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Critical flicker fusion frequency (CFF) is a short but sensitive method for evaluating optic nerve function. We measured CFF in patients with pituitary neuroendocrine tumors (Pit-NETs) to assess its usefulness. Data from 184 patients with nonfunctioning Pit-NETs, who had been treated with transsphenoidal surgery and had no medical history of eye diseases, was used in this retrospective study. Visual acuity decline (VAD) was defined as > 0.10 reduction in logMAR visual acuity and CFF decline (CFD) was defined as CFF value < 35 Hz. Visual field defect (VFD) was evaluated by automated perimetry on a Humphrey visual field analyzer. Potential associations between abnormal test results and tumor height from the suprasellar were analyzed. Contact between the optic nerve or chiasma and the tumor was present and absent in 161 and 23 patients, respectively. In patients showing contact, the difference in CFF between the left and right eyes was larger (p = 0.0008), and the optimal cutoff value using the receiver operating characteristic curve was 3 Hz. Therefore, ≥ 3 Hz was considered positive for CFF laterality (CFL), the most prevalent condition. Tumor height was lower in patients with CFL positivity compared to those with VAD or VFD (p < 0.01). The prevalence of test abnormalities was the highest for small tumors compared to those of other tests. Changes in CFL permit early detection of Pit-NETs. Our results indicate that CFF laterality can be seen in the early stages of compressive optic neuropathy due to Pit-NET. [ABSTRACT FROM AUTHOR]

Purpose: To clarify the invasiveness to surrounding structures and recurrence rate of each subtype of nonfunctioning pituitary neuroendocrine tumor (Pit-NETs) according to the WHO 2022 classification. Methods: This retrospective study utilized data from 292 patients with nonfunctioning Pit-NETs treated with initial transsphenoidal surgery. Recurrence was evaluated on 113 patients who were available for a magnetic resonance imaging follow-up ≥ 60 months. All tumors were assessed by immunohistochemical staining for Pit-1, T-PIT, and GATA3. Invasiveness to surrounding structures was evaluated based on intraoperative findings. Results: Cavernous sinus invasion was found in 47.5% of null cell tumors, 50.0% of Pit-1 lineage tumors, 31.8% of corticotroph tumors, and 18.3% of gonadotroph tumors. Dura mater defects in the floor of sellar turcica, indicating dural invasion, were found in 44.3% of null cell tumors, 36.4% of corticotroph tumors, 16.7% of Pit-1 lineage tumors, and 17.3% of gonadotroph tumors. In logistic regression analysis, Pit-1 (OR 5.90, 95% CI 1.71–20.4, P = 0.0050) and null tumors (OR 4.14, 95% CI 1.86–9.23, P = 0.0005) were associated with cavernous sinus invasion. Recurrence was found in 8 (4.9%) patients, but without significant differences between tumor subtypes. The presence of cavernous sinus invasion was correlated with recurrence (HR = 1.95, 95% CI 1.10–3.46, P = 0.0227). Conclusion: Among nonfunctioning Pit-NETs, Pit-1 lineage tumors tend to invade the cavernous sinus, corticotroph tumors may produce dura mater defects, and null cell tumors tend to cause both. Pit-NETs with cavernous sinus invasion require a careful attention to recurrence. [ABSTRACT FROM AUTHOR]

Introduction: To investigate the differences in the incidence rates of suspected stage 0/1 osteonecrosis of the jaw (ONJ) and incidence risk of relevant clinical findings of suspected stage 0 ONJ between patients treated with sequential therapy comprising weekly teriparatide for 72 weeks followed by alendronate for 48 weeks vs. those who received monotherapy with alendronate for 120 weeks. Materials and methods: Suspected stage 0/1 ONJ was defined by non-specific symptoms. Tooth mobility and periodontal symptoms (gingival bleeding, swelling, and/or pain) were selected as clinical findings of suspected stage 0 ONJ. Poisson regression models were applied to calculate the incidence rate ratios of suspected stage 0/1 between the teriparatide group (TG) and alendronate group (AG). Generalized linear models were used to calculate the risk ratios of clinical findings between groups. Results: Two hundred and sixty-one participants in the TG and 344 in the AG answered a structured questionnaire on oral health and were included in this study. There were no significant differences between the groups in the incidence rate of suspected stage 0/1 ONJ at both 72 and 120 weeks. The risk ratio of the TG to AG for tooth mobility was 0.34 (95% confidence interval [CI] 0.13–0.88, p = 0.02) at 72 weeks and 0.90 (95% CI 0.40–2.03, p = 0.83) at 120 weeks. The incidence rate of tooth mobility related to periodontal symptoms decreased in the TG and increased in the AG during the study. Conclusion: Tooth mobility accompanied by clinical periodontal symptoms may be a useful early sign of stage 0 ONJ. [ABSTRACT FROM AUTHOR]

Introduction: A 2015 survey of the Japan Osteoporosis Society (JOS) on medication-related osteonecrosis of the jaw (MRONJ) revealed that cooperation between physicians and dentists was poor. Discontinuation of antiresorptive agents before tooth extraction was found to increase adverse events without preventing MRONJ. We compared this 2015 survey with a new survey conducted in 2022 to investigate cooperation between physicians and dentists for MRONJ. Materials and methods: A web-based structured questionnaire including 13 key queries was sent to 3813 physicians who were members of JOS, and 1227 (32.2%) responses were received. Results: Of the 1227 respondents, 909 (74.1%) had complied with a discontinuation request from a dentist before tooth extraction, although 25.4% of medications were not related to the incidence of MRONJ. Of these, 177 respondents reported 252 adverse events including 10 (1.3%) cases of MRONJ. The prevalence of fractures increased from 4.8% in 2015 to 8.2% in 2022. The rates of respondents who requested oral health care by a dentist before antiresorptive agent therapy and reported cooperation between physicians and dentists were 72.7% and 42.4% in 2022 compared with 32.9% and 24.8% in 2015, respectively. The rates of cooperation among the 47 prefectures in Japan were significantly different, ranging from 10.0 to 83.3% (p = 0.02). Conclusion: This study confirmed increased cooperation between physicians and dentists for MRONJ in Japan. However, a more equal distribution of cooperation across Japan is necessary to optimally manage MRONJ. Discontinuation of antiresorptive agents is no longer necessary because fractures during discontinuation continue to increase in Japan. [ABSTRACT FROM AUTHOR]

Introduction: Little is known about whether substances inducing tissue protein degeneration in the oral cavity are associated with the number of teeth present in postmenopausal women. We sought to investigate the association of urinary pentosidine and serum homocysteine levels with the number of teeth and subsequent tooth loss in Japanese postmenopausal women. Materials and methods: Among participants in the Nagano Cohort Study, 785 postmenopausal women (mean age, 68.1 years) participated in the present study. The number of teeth was re-counted at the time of follow-up in 610 women. Poisson regression analysis was used to investigate differences in the number of teeth among quartiles of pentosidine or homocysteine, adjusting for covariates that correlated with the number of teeth. A Cox proportional hazard model was used to evaluate the association of subsequent tooth loss with pentosidine or homocysteine levels. Results: Pentosidine quartiles were not associated with the number of teeth at baseline. Participants in the highest homocysteine quartile had significantly fewer teeth at baseline than those in the third and lowest quartiles (p < 0.001 for both). Those in the second quartile had fewer teeth than those in the third (p = 0.001) and lowest (p < 0.001) quartiles. An increased risk of tooth loss during follow-up was significantly associated with higher urinary pentosidine (hazard ratio = 1.073 for 10 pmol/mgCre; p = 0.001). Conclusion: Postmenopausal women with higher homocysteine levels had fewer teeth at baseline. A higher pentosidine concentration increased the risk of subsequent tooth loss. High pentosidine or homocysteine concentrations may be associated with tooth loss in postmenopausal women. [ABSTRACT FROM AUTHOR]

Endoscopic third ventriculostomy (ETV) for obstructive hydrocephalus and endoscopic biopsy (EB) for intraventricular and paraventricular tumors are standard therapies because they are minimally invasive procedures. Although EB-associated hemorrhagic risk has been well documented, there have been only a few reports on hemorrhagic risk associated with ETV. We conducted a single-institution retrospective study on the incidence of hemorrhage secondary to EB and/or ETV. We retrospectively reviewed patient characteristics, procedure, pathological findings, and complications including hemorrhage of 100 patients with intraventricular and paraventricular tumors who underwent EB and/or ETV at our institution from 2000 to 2020. EB/ETV combined surgery (combined group), EB-alone surgery (EB-alone group), and ETV-alone surgery (ETV-alone group) were performed in 44 (44%), 24 (24%), and 32 (32%) patients, respectively, and all procedures were successful. The rates of definitive and suggestive diagnoses in EB were 76.5% and 23.5%, respectively. Adverse events were observed in 6 patients. In the combined group, acute obstruction of the ETV stoma was observed in 1 patient and transient double vision was observed in 1 patient. Transient aqueductal stenosis/obstruction was observed in 2 patients in the EB-alone group. In the ETV-alone group, hemorrhage was observed in 2 patients; these patients developed intratumoral hemorrhage despite ETV-alone surgery. Subsequently, these 2 patients underwent tumor removal, and the histopathological diagnosis was atypical teratoid/rhabdoid tumor in both. For obstructive hydrocephalus with atypical teratoid/rhabdoid tumor, physicians must be aware of the risk of postoperative intratumoral hemorrhage after performing ETV. [ABSTRACT FROM AUTHOR]

Background: Several recent randomized controlled trials have reported that perioperative complications of carotid artery stenting increase with age, and Japan has the highest proportion of elderly in the world. We retrospectively compared clinical factors, treatment outcomes, and adverse events between younger and elderly carotid artery stenting patients at a single institution in Japan to assess carotid artery stenting safety for the aged population. Methods: A total of 150 consecutive patients treated with carotid artery stenting using the dual protection (simultaneous flow reversal and distal filter) and blood aspiration method were enrolled. Patients were classified into an elderly (O) group ≥75 years (54/150, 36.0%) and a younger (Y) group <75 years (96/150, 64%) for comparison of demographics, clinical background, incidence of captured debris during the procedure, outcome, minor stroke, major adverse events (major stroke, myocardial infarction, or death) within 30 days, hyperintense spots on diffusion-weighted images after carotid artery stenting, and postoperative hospitalization days. Results: The carotid artery stenting procedure was successful in all cases. No major adverse events occurred within 30 days in the Y group, and only one occurred in the O group (P = 0.348). Visible debris was captured in a significantly greater proportion of O group patients than in Y group patients (33/54 (63.5%) vs. 40/96 (42.1%), P = 0.016), but there was no significant difference in the frequency of hyperintense spots on diffusion-weighted images between Y and O groups (23/96 (24.0%) vs. 16/52 (30.8%), P = 0.435). Conclusions: Carotid artery stenting using dual protection and blood aspiration is equally safe for younger and elderly patients. [ABSTRACT FROM AUTHOR]

Introduction: Fragility fractures can cause delayed wound healing after tooth extraction, which contributes to an increased risk of osteomyelitis of the jaw. We evaluated whether a history of fragility fracture was associated with increased risk of delayed wound healing after tooth extraction in older adults in Japan.Materials and Methods: Of 5352 people aged 50-89 years in the 2014 basic resident registry of the town of Obuse, the present study included 376 subjects (190 men and 186 women) who completed a structured questionnaire and measurement of the bone mineral densities (BMDs) of the bilateral femoral neck. Delayed wound healing after tooth extraction was self-reported. Fragility fractures were confirmed via examination of hospital medical records. Logistic regression analyses adjusted for age and gender were used to evaluate association of clinical variables with delayed would healing after tooth extractions. Odds ratios (ORs) and the 95% confidence intervals (CIs) of all possible associated variables for the presence of delayed wound healing were calculated.Results: Subjects with a history of fragility fractures had a significantly higher risk of delayed wound healing compared with those without previous fragility fractures (OR 2.68; 95% CI 1.11-6.46, p = 0.028). This association still remained after adjusted for all other variables (OR 2.70; 95% CI 1.10-6.60, p = 0.030). Delayed wound healing was not significantly associated with the BMD of the femoral neck.Conclusions: History of fragility fracture may be associated with increased risk of delayed wound healing after tooth extraction in Japanese men and women aged 50-89 years. [ABSTRACT FROM AUTHOR]

Osteonecrosis of the jaw (ONJ) associated with bisphosphonate therapy is a rare but severe side effect in osteoporosis patients. Recently, the number of osteoporosis patients with ONJ has dramatically increased in Japan. This has contributed to an increase in the number of patients avoiding extractions. However, there has been no prospective study providing definitive incidence data for ONJ in Japanese patients. The purpose of this study was to elucidate the true as well as suspected incidence of ONJ. A total of 3229 subjects (1612 subjects in the minodronic acid group and 1617 subjects in the raloxifene group) in the Japanese Osteoporosis Intervention Trial protocol number 4 participated in this study. ONJ was diagnosed by experienced dentists. Suspected Stage 0 and 1 (bone exposure of the jaw) ONJ was assessed by a structured questionnaire at baseline and at 6, 12, 18, and 24 months. No established ONJ cases were diagnosed during the study. The incidence of suspected Stage 0 and/or Stage 1 ONJ was 6.14 per 1000 patient-years in the minodronic acid group and 3.38 per 1000 patient-years in the raloxifene group [hazard ratio (95% confidence interval) = 1.82 (0.84-3.93), P = 0.13]. Approximately 50-60% of bone exposures that appeared during the study had disappeared at the next observation. Although the subjects in this study may have developed a greater interest in the health of the oral cavity, the incidence of ONJ after minodronic acid treatment would be lower than the expected incident rate. [ABSTRACT FROM AUTHOR]

Background: While it is well known that teriparatide (TPTD) increases bone mineral density (BMD) in osteoporotic patients, it is unknown whether TPTD pretreatment affects BMD after denosumab (DMAb) therapy.Methods: Fifty-seven patients in TPTD-pretreated group and 35 patients in DMAb-alone group had been further analyzed, all of whom were treated by DMAb for 1.5 years. Vitamin D (400 IU) and Ca (600 mg) supplementation was used in all patients. The BMD of lumbar 1-4 vertebrae (L-BMD), bilateral total hips (H-BMD), and bilateral femoral neck (FN-BMD) was quantified at first visit, and at 4, 8, 12, and 18 months after daily TPTD treatment following four times DMAb treatment.Results: There were significant differences in L-BMD (p=0.004) and H-BMD (p=0.026) at baseline between TPTD-pretreated and DMAb-alone groups, although there was no significant difference in FN-BMD between the two groups. The increase of L-BMD by DMAb therapy was less in TPTD-pretreated group than in DMAb-alone group. There was no significant difference in H-BMD, although percent changes of H-BMD tended to be higher in the TPTD-pretreated group than those in the DMAb-alone group. Percent change in FN-BMD at 4 months (p=0.067) and 12 months (p=0.057) tended to be higher in TPTD-pretreated group than in DMAb-alone group. Percent change in FN-BMD at 18 months was significantly higher in TPTD-pretreated group (p=0.004) than in DMAb-alone group.Conclusion: These findings suggest that the pretreatment of TPTD might have enhanced the increase of BMD in cortical bones treated by DMAb. Thus, it is favorable that TPTD can be used for osteoporotic patients who have high fracture risks with cortical bones. [ABSTRACT FROM AUTHOR]

The desorption and enrichment of tritiated water from organic functionalized mesoporous SBA-15 were investigated. The desorption behavior of tritiated water was dependent on the nature of the organic functional group present i.e., COOH, SO 3 H, and NH 2 . Enriched tritiated water was obtained by thermal desorption from SO 3 H and NH 2 grafted SBAs after spontaneous desorption of tritiated water at 25 °C. Although the volumetric amount of concentrated tritiated water was small, the concentration ratios of tritiated water thermally desorbed and at 25 °C were 1.2 and 1.3 for SO 3 H and NH 2 grafted SBA, respectively. In contrast, COOH grafted SBA showed a lower T concentration after thermal desorption. Fourier transform infrared spectroscopy studies using deuterated water (D 2 O) indicated the presence of strong interactions between COO groups and D. [ABSTRACT FROM AUTHOR]

Objective: Our previous questionnaire-based survey suggested that discontinuation of antiresorptive agents before tooth extraction may increase adverse events and disturb osteoporosis treatment without completely preventing osteonecrosis of the jaw (O.N.J.). We also found little cooperation between physicians and dentists in Japan. However, limitations of our previous study included a survey of doctors belonging to small clinics and a small sample size. Our current study aimed to confirm the results of our previous survey in doctors mainly belonging to academia.Methods: A structured questionnaire including 14 key clinical queries was sent to 1812 physicians of the Japan Osteoporosis Society, and 629 responses were received.Results: Dentists requested discontinuation of many medications that were not associated with the incidence of O.N.J. A total of 523 respondents had received discontinuation requests from dentists. Of these, 97 respondents experienced 119 adverse events including 25 fractures and seven incidences of O.N.J. The ratios of valid responses for fractures were 3.6% and 5.3% in patients with a discontinuation of <3 and ≥3 months, respectively. Those for O.N.J. were 0.7% and 1.6%, respectively. Respondents who refused discontinuation requests reported no cases of O.N.J. Approximately 17% of respondents had patients who discontinued osteoporosis treatment following a requested drug discontinuation after tooth extraction. Approximately 62% of respondents did not request oral health care by a dentist before antiresorptive therapy, and 72% reported no cooperation between physicians and dentists in their region.Conclusions: This study reconfirms the results of our previous survey. Discontinuation of antiresorptive treatment may increase both fractures and O.N.J. Immediate development of a strategy for sharing information about O.N.J. among physicians, dentists, and patients is required to reduce the incidence of both O.N.J. and skeletal events in osteoporosis treatment. Study limitations were selection bias due to low response rate and possible inaccurate responses to the questionnaire. [ABSTRACT FROM AUTHOR]

Dentists request a discontinuation of antiresorptive agents, such as bisphosphonate, before and after tooth extractions to prevent osteonecrosis of the jaw (ONJ). However, little is known about how this affects ONJ and osteoporosis treatment and how medical professionals and dentists cooperate to treat ONJ in patients with osteoporosis. This study aimed to clarify the impact of ONJ on osteoporosis treatment in Japan. A structured questionnaire including 14 key clinical queries was sent to 488 medical professionals as part of the Japanese Osteoporosis Intervention Trial (JOINT)-04, and 206 responses were received. A total of 173 respondents had received discontinuation requests from dentists. Of these, 28 respondents experienced 30 adverse events including ten fractures and one incidence of ONJ. The respondents who refused discontinuation requests observed no cases of ONJ. Approximately 16 % of respondents had patients who discontinued osteoporosis treatment, following a requested drug discontinuation, after tooth extraction. Dentists requested discontinuations for many medications that were not associated with the incidence of ONJ. Approximately 76 % of respondents had never requested oral health care from dentists before osteoporosis treatment and 72 % reported no cooperation between dentists and medical professionals in their region. Our results suggest that drug discontinuation may increase adverse events and disturb osteoporosis treatment without completely preventing ONJ. Currently, both medical professionals and dentists in Japan still continue to recommend their own treatment position. A forum to share information about ONJ among medical professionals, dentists, and patients is required. [ABSTRACT FROM AUTHOR]

Background: Poor oral health is associated with an increased risk of dementia in the elderly. One possible pathway linking these two phenomena is lacunar infarction, a potential cause of dementia. An association between poor oral health and an increased risk of ischaemic stroke has been recognised through the oral infection-inflammation pathway. However, little is known about whether poor oral health is associated with the progression of lacunar infarction. Objective: We examined the association between variables related to oral health and lacunar infarction, as detected by magnetic resonance imaging (MRI). Methods: A total of 110 subjects (52 men, 58 women), aged 27-76 years, who visited our periodontology clinic participated in this study. The subjects underwent dental radiography, periodontal examinations and brain MRI. One experienced specialist in cardiovascular disease and one experienced neurosurgeon determined the number of lacunar infarctions on brain MRI. Periodontologists performed clinical periodontal examinations. Variables related to oral health were determined from the radiographs by an oral radiologist. Information on the subjects' lifestyles and disease histories were obtained using a structured questionnaire and confirmed by clinical records. Adjacent categories logit regression analysis with backward elimination was used to determine variables associated with three groups based on the number of lacunar infarctions. Results: Of the 110 subjects, 61 had lacunar infarctions. Nineteen had multiple (≥7) lesions. Aging (p = 0.0004), increased time spent in physical activity per day (p = 0.042), the presence of hypertension (p = 0.006), the absence of hyperlipidaemia (p = 0.045), the presence of diabetes mellitus (p = 0.025) and low alveolar bone height (p = 0.026) were significantly associated with an increased number of lacunar infarctions in the final regression model. The significance of hyperlipidaemia and alveolar bone height disappeared in an unadjusted model. An increased pocket depth, which indicates current periodontal disease progression, tended to be associated with an increased number of lacunar infarctions (p = 0.058). This tendency did not disappear in an unadjusted model. Conclusion: Our results suggest that lacunar infarction may be associated with current periodontal disease in Japanese adults. Copyright © 2013 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Bit-length of digital images is decided by the Analog-to-Digital (AD) converter. The bit-length expansion technique is necessary for high-quality displays such as the liquid crystal display (LCD) and the plasma display. Bit-length expansion is also necessary for low-bit length images, which are degraded by the pseudo-contour. In this paper, we propose a bit-length expansion method from M-level to N-level [N=3(M-1)+1]. This operation means that two quantization levels are introduced between existing levels. The bit-length expansion method results in the estimation problem of an error image between an M-level's image and an N-level's image. The error image is the pattern image which consists of three values. We show the estimation method of the three values pattern image and that the proposed method can remove the pseudo-contour of digital images through several application results. © 2009 Wiley Periodicals, Inc. Electron Comm Jpn, 92(10): 32–40, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10105 [ABSTRACT FROM AUTHOR]

Abstract: The transition of Pt from a nanoparticle to a film on SiO2 particles modified by the sputtering system with barrel-type powder sample holder (the barrel sputtering system). X-ray diffraction (XRD) and scanning electron microscopy (SEM) measurements reveal that the Pt nanoparticles grow in size with an increase in the duration of sputter deposition. The morphology of Pt changes from highly dispersed nanoparticles to a worm-like structure followed by a continuous Pt film, depending on the amount of Pt modified. Transmission electron microscopy (TEM) measurements reveal that the thin Pt film in the worm-like structure has a uniform thickness of approximately 2.6nm, indicating film growth in a two-dimensional mode followed by an island mode. [Copyright &y& Elsevier]

Abstract: Our newly developed “barrel-sputtering” technique has been employed for the surface coating of solid substrates with complex shapes such as bolts, nuts, and screws. The entire surface of the iron bolts and nuts including the flank and the root in the thread is homogeneously coated with the Au film. SEM measurements reveals that the surface of the Au film is very smooth. In the SEM measurements of the cross-sectional area, it is found that the Au film possess uniform thickness without any significant defects and/or pits. The Au film coating can also be successfully conducted on polycarbonate bolts and small SUS screws. The results provide evidences that the sputter deposition takes place in “three-dimensionally.” [Copyright &y& Elsevier]

Abstract: Micron-sized spherical polymer particles were homogeneously coated with Au, Ag, Pd, Cu, and Ni by the barrel sputtering technique. Surface coating was successfully performed independent of the sputtered metal and the diameter of the polymer particles used. Optical microscope observations revealed a mirror-like appearance with a color that depended on the coated metal. SEM and EDX studies revealed that the surface of metal-coated samples was very smooth and the sputtered metal was homogeneously distributed over the entire sample surface. The amount of coated metal was evaluated using TG–DTA and ICP-AES measurements. The thickness of the metal film was within several 10nm. [Copyright &y& Elsevier]

In the information and communications field, digital images have come to be widely used in mobile communications devices, and digital image processing is very important. Because of the different resolutions of the displays and output devices in each terminal, digital images undergo reduction and enlargement processing very frequently. Conventionally, reduction and enlargement processing is performed using an interpolation algorithm based on the sinc function. However, because the frequency band increases when digital images are enlarged, an enlarged image of sufficient quality cannot be attained through interpolation. In recent years, an enlargement method has been proposed which uses estimation of the frequency bands (high-frequency components) which increase with the enlargement of a digital image. The authors have also clarified interpolation algorithms using the preservation of step edge signals, coordinate point warping for generating peak signals, and signal amplitude biasing. They have implemented an interpolation algorithm which produces high-frequency components. In calculating the bias in this method, the smaller of the biases found to either side of the interpolation is selected. This choice is not necessarily optimal; the larger bias should be selected depending on certain conditions. For example, the selection of the larger bias makes it possible to preserve the precipitous changes in a step edge signal. This makes it possible to preserve step edge signals and generate peaks, without also using coordinate point warping, by selecting the optimal bias according to local information. The proposed interpolation algorithm using data-dependent biasing was compared to an interpolation algorithm using coordinate point warping and signal amplitude biasing. The proposed algorithm was found to have a similar performance and clearly shown to be a method with low computational complexity. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(8): 18–28, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20306 [ABSTRACT FROM AUTHOR]

The authors have addressed developments of SMES system effective for power system stabilizing control. Focused on control logics that can be used to efficiently regulate SMES, a number of unique control logics were devised by combining the popularly used power deviation (ΔP) of a generator with the angular velocity deviation (Δw) of a generator or the phase correction. We practiced a digital simulation analysis for the created logics under both conditions of one- and multi-machine infinite-bus systems using the Y-method power system dynamics analysis program, which was compiled by the CRIEPI. As a result, it was revealed that the rated capacity and the amount stored energy of SMES necessary for power system stabilizing can be reduced by approximately 3 to 5% when compared to that obtained by employing the conventionally used ΔP control method alone. [ABSTRACT FROM AUTHOR]

The YUV 4:2:0 format is a representative format for color images in international standards. In this format, both color difference components U and V reduce the number of pixels in the horizontal and vertical directions by one-half. Consequently, this reduction degrades the color difference components. At a relatively high bit rate, the degradation produced by reducing the number of pixels is often worse than the degradation that depends on the coding. Thus, processing to compensate for the degradation due to the format transform becomes necessary. The pixels of the color difference components reduced once on the encoding side are determined by interpolation on the decoding side. The typical interpolation methods are bilinear interpolation, bicubic interpolation, and interpolation by a finite impulse response (FIR) filter. When these interpolation methods were applied to interpolate the color difference components in the YUV 4:2:0 format, blur and lower saturation were produced in the colors in the color difference components returned to the original number of pixels. In this paper, we propose a method that uses information in the luminance component not having a reduced number of pixels to interpolate the color difference components in the YUV 4:2:0 format. Consequently, color blurring is prevented in the edges of the image, and an objective is to improve the saturation in the entire image. We based the proposed method on bilinear interpolation and bicubic interpolation, and formulated an interpolation method using the luminance component as an extended form. The proposed method and the bicubic interpolation are compared in both objective and subjective evaluations, and demonstrate the effectiveness of the proposed method. © 2006 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 89(9): 1–10, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20218 [ABSTRACT FROM AUTHOR]

When a multiscale digital image is output into a device with fewer simultaneous generation scales, such as two scales (black and white), halftoning is performed for approximate representation of the grayscale. A typical approach is the error diffusion method. Problems in this error diffusion method are the generation of regular patterns (worms) in the flat portion and of constant value regions not halftoned after variations where the signal varies suddenly. In this paper, the constant value region is investigated. A new method is proposed to avoid constant value regions. The constant value region is generated by diffusion of the quantization error with an inappropriate value for the forward scanning direction. In order to prevent this problem, the edge sections where generation of the constant value region is expected are eliminated by a smoothing filter. In this way, inappropriateness of the quantization error values for regions with different values in the forward scanning direction is suppressed. In order to prevent blurring of the input image, the filtering process is a data-dependent type that is limited to avoiding constant value regions. The proposed method is a simple one allowing avoidance of the constant value region without causing blurring by inserting a simple data-dependent prefilter. © 2006 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 89(5): 1–11, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20214 [ABSTRACT FROM AUTHOR]

Abstract: Mechanical grinding (MG) leads to a sequential phase transition of γ-MnO2 to form the thermodynamically stable α-Mn2O3 and, subsequently, Mn3O4 depending on the duration of MG treatment. By MG treatment for 150h, α-Mn2O3 became a predominant species. A subsequent transition to Mn3O4 was observed on further MG treatment for 200h. The particle size of the resultant manganese oxides was reduced to as small as 20nm after 300h of MG treatment. The change in the specific capacitance of manganese oxides obtained was monitored by XRD and electrochemical experiments. It was observed that the specific capacitance of MG-treated manganese oxides depends on the amount of γ-MnO2 left without phase transition. [Copyright &y& Elsevier]

Introduction: Eroded or thin inferior cortex of the mandible detected on dental panoramic radiographs may be useful for identifying postmenopausal women with low bone mineral density (BMD) or osteoporosis. The purpose of this study was to evaluate whether these panoramic measurements are useful for identifying low BMD or osteoporosis in postmenopausal women younger than 65 years. Methods: We compared the diagnostic performances of panoramic measurements with those of the osteoporosis self-assessment tool (OST) for identifying women with low BMD (T-score of −2.0 or less at either the lumbar spine or the femoral neck) and osteoporosis (T score of −2.5 or less) in 158 healthy Japanese postmenopausal women aged 46 years to 64 years. Mandibular cortical shape (erosion) and width were evaluated on dental panoramic radiographs. Receiver operating characteristic curve analysis was used to determine the optimal cutoff thresholds for cortical width and OST index. Results: The sensitivity and specificity, respectively, for identifying women with low BMD were 82.3% and 55.2% for OST index, 79.0% and 50.0% for cortical width, and 72.6% and 74.0% for cortical shape. The sensitivity and specificity, respectively, for identifying women with osteoporosis were 86.7% and 46.9% for OST index, 90.0% and 45.3% for cortical width, and 86.7% and 65.6% for cortical shape. Likelihood ratio for identifying women with low BMD was 13.90 for thin cortical width (<3.0 mm) and 10.84 for severely eroded cortex. That for identifying women with osteoporosis was 6.40 for thin cortical width and 7.11 for severely eroded cortex. Conclusions: Dentists may be able to refer postmenopausal women younger than 65 years for bone densitometry on the basis of incidental findings on dental panoramic radiographs. [ABSTRACT FROM AUTHOR]

Dentists are a potentially valuable resource for initial patient screening for signs of osteoporosis, as individuals with osteoporosis have altered architecture of the inferior border of the mandible as seen on panoramic radiographs. Our aim was to evaluate the efficacy of combining clinical and dental panoramic radiographic risk factors for identifying individuals with low femoral bone mass. Bone mineral density was measured at the femoral neck and classified as normal, osteopenic or osteoporotic using WHO criteria in 227 Japanese postmenopausal women (33-84 years). Panoramic radiographs were made of all subjects. Mandibular cortical shape and width was determined and trabecular features were measured in each ramus. Mean subject age, height, and weight were significantly different in the three bone-density groups (P<0.0001). A classification and regression trees (CART) analysis using just clinical risk factors identified 136 (87%) of the 157 individuals with femoral osteopenia or osteoporosis. Mean mandible cortical width (P<0.0001), cortical index (P<0.0001) and trabecular features (P=0.02) were also significantly different in the three bone density groups. A CART analysis considering only radiographic features found 130 (83%) of the 157 individuals with femoral osteopenia or osteoporosis, although none of the subjects with osteoporosis was correctly identified. A CART analysis using both clinical and radiographic features found that the most useful risk factors were thickness of inferior border of the mandible and age. This algorithm identified 130 (83%) of the 157 individuals with femoral osteopenia or osteoporosis. The results of this study suggest that 1) clinical information is as useful as panoramic radiographic information for identifying subjects having low bone mass, and 2) dentists have sufficient clinical and radiographic information to play a useful role in screening for individuals with osteoporosis. [ABSTRACT FROM AUTHOR]

Since the dimensions for digital images are set by the acquisition system, digital image enlargement is indispensable when the dimensions that can be displayed are larger in the display system than in the acquisition system. Conventionally, this enlargement process was performed by interpolation. The digital image enlargement corresponds to a larger Nyquist frequency, but the frequency band that is expanded during the enlargement cannot be considered by the interpolation scheme, and blur is produced in the enlarged image. The parts where the image blur stands out subjectively are primarily the signals forming the image contours having the step edge shape and the details of the image consisting of mountain- and valley-shaped signals when viewed microscopically. Therefore, the proposed method moves the coordinate points interpolated to preserve the discontinuities of step edge signals and decides whether the interpolated points are the vertices of the mountain- or valley-shaped signals, and then moves the amplitudes of the interpolated points for creating these peak signals up or down. In other words, we explain an interpolation scheme involving the warping and biasing that randomly moves the coordinate points and the signal amplitudes, and implement digital image interpolation with improved resolution. Furthermore, the parameter settings for the proposed method are both objectively and subjectively evaluated. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 88(2): 10–21, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20095 [ABSTRACT FROM AUTHOR]

Abstract: Ordered mesoporous catalysts could open the door for new catalytic processes, based partly on novel principles, owing to their hitherto unprecedented intrinsic features. For the preparation of ordered mesoporous catalysts, many strategies have been described. These strategies and the essential properties of the resulting materials are described in the first part of this review. Catalytic processes over such mesoporous materials, especially such reactions where the specific features of ordered mesoporous catalysts are exploited, are described in the second part. [Copyright &y& Elsevier]

The purpose of this case-control study was to determine if elderly subjects with a history of osteoporotic fractures have fewer teeth and greater residual ridge resorption than subjects without such fractures. Patients older than 60 with a panoramic radiograph were invited to a phone interview. Information was obtained regarding fracture history, smoking, and hormone replacement therapy (HRT). The number of teeth was obtained from the panoramic radiograph. The residual ridge height of the edentulous mandible was measured at the site of the mental foramen. Multiple regression models were used to assess the association between fracture status and number of teeth or residual ridge height (controlling for age, gender, HRT, smoking, height and weight). Cases (n=93) were individuals reporting osteoporotic fractures (fractures occurring after minor impact). Controls (n=394) were individuals reporting traumatic fractures (n=105) or no fractures (n=289). Fracture status in this population affect neither the number of teeth nor the residual ridge height. In the regression model, the variables that had a statistically-significant effect on the number of teeth were age (p<0.0001) and smoking (p<0.0001). There was a dose-effect of smoking on the number of teeth. In the regression model, the variables that had a significantly-significant on residual ridge height (n=95 edentulous subjects) were age and gender. Our conclusion was that in elderly dental-school patients the number of teeth and residual ridge height were not influenced by fracture status. Age and smoking had the most influence ; there was no effect from HRT. The clinical implication is that a history of osteoporotic fractures is not an important cause for tooth loss and residual ridge resorption in an elderly dental-school population. [ABSTRACT FROM AUTHOR]

Recent studies suggest that a small number of remaining teeth may be associated with low skeletal bone mineral density (BMD) in postmenopausal women. Estrogen deficiency after menopause is considered potential cause relating to tooth loss accompanied by low skeletal BMD in women. Since estrogen plays a dominant role in regulating the male skeleton, it is likely that a small number of remaining teeth also may be associated with low skeletal BMD in men. However, it remains uncertain whether tooth loss is associated with low skeletal BMD in both men and women. We investigated the association between self-reported number of remaining teeth and BMD of the spine and the femoral neck in a cohort of 1914 Japanese subjects aged 48-95 years who were recruited from the Adult Health Study conducted by the Radiation Effects Research Foundation (RERF). BMD of the spine and the femoral neck was measured by dual energy X-ray absorptiometry (DXA). Tooth count was self-reported in response to a simple question to subjects about the number of remaining teeth they had at the time of the survey. Multiple regression analysis adjusted for age, weight, height, smoking, estrogen use, and years since menopause revealed a significant association between number of remaining teeth and BMD of the femoral neck in both men and women; however, no association was found between number of remaining teeth and BMD of the spine in both sexes. Retention of four teeth was significantly associated with a 0.004 g/cm2 increase in femoral neck BMD in men (P<0.05), which was similar to that observed in women (P<0.01). Our results suggest the presence of common causes, except age and body weight, relating to tooth loss accompanied by low BMD of the femoral neck in both men and women. [ABSTRACT FROM AUTHOR]

It is widely believed that the vasculature plays an important role in bone remodeling. We investigated the relationship between forearm endothelial function and bone mass in the lumbar spine in early postmenopausal women without a history of smoking or diabetes mellitus.We studied the forearm resistance artery endothelial function in 110 Japanese women—52 postmenopausal women with normal spinal bone mineral density (BMD), 36 postmenopausal women with osteopenia, and 22 osteoporotic postmenopausal women. Forearm blood flow (FBF) during reactive hyperemia and after sublingual nitroglycerin (NTG) administration was measured by strain-gauge plethysmography. BMD of the lumbar spine (L2–L4) was measured by dual-energy X-ray absorptiometry. After adjustment for age, body mass index, years since the start of menopause, and basal FBF, women with osteoporosis had a lower maximal FBF response to reactive hyperemia (28.4 ± 3.8 mL/min per 100 mL tissue) than those with normal BMD (39.8 ± 2.8 mL/min per 100 mL tissue) or osteopenia (35.6 ± 2.5 mL/min per 100 mL tissue) (P = 0.029). A significant increase in serum angiotensin-converting enzyme (ACE) activity (P = 0.042) and a significant decrease in the serum concentrations of nitrite/nitrate (P = 0.041) were noted in osteoporotic women compared to women with normal BMD or osteopenia.The present findings suggest that postmenopausal women with low BMD, especially those with osteoporosis, have impaired endothelial function in the forearm resistance arteries. [Copyright &y& Elsevier]

Enlargement of digital images is equivalent to narrowing the sampling spacing. Hence, it is necessary for enlargement of the digital images to estimate the high-frequency components lost in the sampling by some means. Recently, an enlargement method accompanied by estimation of lost high-frequency components has been proposed. The present authors have also noted the Laplacian pyramid layer expression, which is a multiresolution representation of digital images, and have proposed an enlargement method to estimate lost high-frequency components. Based on the Laplacian pyramid layered representation, estimation of unknown high-frequency components is equivalent to estimation of unknown high-resolution Laplacian components. Since the layered expression of the Laplacian pyramid has band division encoding as the objective, the image size between the layers is 2 and the enlargement method based on this expression is also limited to 2. However, it is possible to obtain a layered expression with an arbitrary size ratio by varying the passband width of the Gaussian filter and eliminating the pixels corresponding to the bandwidth, in place of continuous use of the half-band Gaussian filter and downsampling of the usual Laplacian pyramid layered image. In this paper, based on this concept, an enlargement method with high-frequency component estimation that allows setting of an arbitrary enlargement rate is proposed. The effectiveness of the proposed method is clarified from abundant application examples. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 86(8): 41–51, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.10018 [ABSTRACT FROM AUTHOR]

One excellent method for restoration of images with superposed impulsive noise uses the position information of the impulsive noise for the pixels used for processing and of the processing point. This method consists of two steps. In Step 1, the impulsive noise existing in the image is detected and the noise position image is formed. In Step 2, by using the noise position image formed in Step 1, the filter processing is carried out on the pixels degraded by impulsive noise only with the pixels not affected by the impulsive noise. An excellent procedure for Step 2, using an average filter (PSA filter), has been proposed. However, in the method with an average filter, a uniform weight is provided on all pixels in the filter window. Therefore, if the generation probability of the impulsive noise is increased, the window size cannot be increased even if the filter window size should be increased. Also, an individual image has directionality specific to the image. This directionality is not taken into account in the filter processing. In the present paper, in order to resolve this problem, a PSWA filter is proposed for the filter processing in Step 2 by using the weighted average filter with weights considering the distance from the process point and the directionality of the image. In order to appropriately apply the proposed filter, there are two parameters (window size N and parameter κ) to be set. From experimental investigation, it is found that these two parameters do not depend on the type of the original image but only on the generation probability of the impulsive noise. Further, from the generation probability of the impulsive noise, the method for providing these two parameters is presented specifically. The effectiveness of the proposed method is confirmed through several processing examples. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 86(3): 33–43, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.1138 [ABSTRACT FROM AUTHOR]

Enlargement processing of digital images is usually carried out by means of an interpolation function obtained by simplification of the sinc function. However, in such an interpolation method, restoration of the high-frequency components lost in digitizing the images is not carried out at all. Hence, the enlargement causes blurring for images with many edges and detailed signals. For one-dimensional signals, Carrato and colleagues have proposed an interpolation method in which the discontinuities of the step edge signals are preserved while other signals are linearly interpolated. In this method, no blurring occurs in the expansion processing of strong frames of the images. However, Carrato's method has the following problems. (1) Only the step edges in the image signals are taken into account so that consideration of the detailed signals is insufficient. (2) Extension of the one-dimensional interpolation method given by Carrato to a two-dimensional interpolation method has a problem in interpolation at the center of the lattice. In this paper, a method is proposed to accomplish improvement of Carrato's method. With regard to problem (1), the interpolation not only is effective for the step edge signals but also preserves the apex of the peak and valley signals. With regard to problem (2), improvement is planned by directly deriving the interpolation value from the original signals. The proposed interpolation processing is accomplished by describing the processing sequence by a rule. The proposed method consists of two sets of fuzzy reasoning. The proposed method and the conventional interpolation method are compared from the numerical and visual perspectives and the effectiveness of the proposed method is clarified. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 86(3): 57–66, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.1140 [ABSTRACT FROM AUTHOR]

The digitization and restoration of images that have been degraded by white or black blotches seen in motion picture films prior to the 1950s have attracted attention. Conventional restoration methods are composed of two processes. The first process is motion estimation by block matching (BM). The second process matches the current frame to the previous and next frames based on the motion estimates and filters in the temporal direction. Blotch detection accompanies the filtering in the second process. The BM used in the first process is average BM or sorted BM. Blotch detection in the second process employs Spike Detection Index-a (SDIa). In conventional BM, however, there are limits to the accuracy of motion estimation when blotches are present in the blocks used to estimate the motion in images corrupted by blotches. Furthermore, the accuracy of the filtering in the second process is affected by the accuracy of the motion estimation. And although blotch detection based on SDIa is a simple method, the accuracy of its blotch detection is a problem. To solve these problems in this paper, we create a blotch position image by using a median filter with an iteration constraint as the first stage, and obtain a virtual original image with the blotches removed by filtering based on the blotch position image. The accuracy of the motion estimation is improved by using the virtual original image, and the accuracy of the filtering is improved by using the blotch position image in the filtering. Based on these innovations, we propose a new method to obtain a restored image sequence having enhanced image quality. The effectiveness of the proposed method is clearly demonstrated through a variety of examples. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 85(10): 8–18, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.1121 [ABSTRACT FROM AUTHOR]

The authors propose a new method for restoring images corrupted by high-probability impulsive noise at 10 to 50%. The strength (number of instances) of impulsive noise present in the area adjacent to a processing point is not uniform even in images that are corrupted by high-probability impulsive noise. In addition, when a processing point itself does not represent high-probability impulsive noise, outputting the input signal as is without performing median filter processing is vital to avoid image degradation. Given the above, one approach for restoring images degraded by high-probability impulsive noise is to first determine whether or not a processing point represents impulsive noise, and then perform median filter processing only when it is determined that impulsive noise is present. Second, when performing median filter processing, the amount of impulsive noise adjacent to a processing point must be estimated, the size of the filter window appropriate to that amount must be set, and efforts to preserve the signal must be made. In the proposed method the authors were able to unify three types of fuzzy inference. In addition, the proposed method is superior at handling images degraded by impulsive noise over a probability range of 10 to 50% when the fuzzy sets are fixed by setting the fuzzy sets in the three fuzzy inferences appropriately. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 85(9): 43–57, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.1118 [ABSTRACT FROM AUTHOR]

We propose a method that uses multiple Wiener filters based on region decomposition to restore natural images degraded by Gaussian noise. Usually, a Wiener filter is designed to be optimal for the entire image. However, because natural images are highly nonstationary, an effective method switches to the optimum filter for each local region. In this paper, we consider a method that repeatedly decomposes into four equal parts, the four regions obtained by dividing an image into four equal parts, and design a Wiener filter for each region. As the regions become smaller, the desired Wiener filter is not necessarily obtained because of the drop in reliability of the correlation functions used to find the Wiener filter. Therefore, we first study to what extent the restoration accuracy of a known source image is improved by ideal decomposition that repeatedly decomposes only regions where the accuracy will improve. We then present a practical method that sufficiently improves the restoration accuracy even when the source image is unknown. We next merge similar decomposed regions and investigate how many classes are essential for the decomposition and these class boundaries. Thus, we verify that the proposed decomposition implicitly accounts for properties such as the contours in the image and clearly demonstrate the suitability of the proposed method. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 85(8): 51–61, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.1112 [ABSTRACT FROM AUTHOR]

In the enlargement of a digital image, it is required to estimate the high-frequency components, which were lost in sampling. As a method of meeting this requirement, the authors have proposed an image enlargement method using a high-resolution neural network (NN). The high-resolution neural network provided excellent results of image enlargement. There remained, however, the following two problems. (1) When the image is enlarged by the high-resolution NN, artifacts are produced in the smooth region of the enlarged image when the magnification ratio is increased as 4, 8, . . . . (2) There is a variation of approximately 10% in the accuracy of the enlarged result, depending on the kind of image used in the training of the high-resolution NN. In order to cope with such problems, this paper newly proposes the high-resolution multi-neural network (MNN), which is based on the local variance. The training procedure is shown. In the high-resolution MNN, two NN are used, corresponding to the region with a rapid change (high local variance) and the region requiring a smooth interpolation (low local variance), in the image for which resolution improvement is required. The weighted sum of the two NN outputs is defined as the result of enlargement. It is shown through application examples that the two problems in the high-resolution NN are remedied by using the high-resolution MNN. © 2001 Scripta Technica, Electron Comm Jpn Pt 3, 84(11): 61–69, 2001 [ABSTRACT FROM AUTHOR]

Discusses the restoration of a signal corrupted by additive noise and develops a smoothing filter which can utilize both the rank-and temporal-order information of the input data. Canonical linear combination of weighted order statistics (LWOS) filter and its optimal design; Modified LWOS filters based on threshold decomposition; Applications of modified LWOS filters to image restoration.

We propose a new model of texture images using morphological filters. This method is based on a linear predictive model [autoregressive (AR) model], which is a representative texture image model. This method embeds the frequency characteristics of the texture image in the AR model. In this paper, we will demonstrate a new model that represents the spatial features of a texture image. Morphological filters can remove the spatial features and are used for pattern spectra. In this paper, we consider embedding the spatial features in the structuring elements of morphological filters and propose an Opening Model (OM) to model the convex up features and a Closing Model (CM) to model the convex down features. We examine the reliability of the proposed model and present improvements to the low-reliability model. Furthermore, our recognition tests clearly show excellent recognition when OM and CM are used together. © 2001 Scripta Technica, Electron Comm Jpn Pt 3, 84(7): 53–62, 2001 [ABSTRACT FROM AUTHOR]

Since the enlargement of digital images is carried out by insertion of sample points, the Nyquist frequency of the enlarged image is naturally larger than that prior to enlargement. Hence, estimation of unknown higher-frequency components is required for enlargement of digital images. On the other hand, Laplacian pyramid representation is widely known as a layered expression of the images. Based on this Laplacian pyramid representation, the unknown higher-frequency components to be estimated at the time of enlargement of digital images correspond to the unknown higher-resolution Laplacian components. There is strong correlation between the Laplacian images at different layers. Specifically, the edge information spans several continuous layers as zero crossings and hence appears at the same location. Differences in the layers are recognized as differences in gradient near the zero crossing. In this paper, this property is directly used to provide a method of obtaining unknown higher-resolution Laplacian images from low-resolution Laplacian images (direct method). The results of enlargement by the direct method are particularly good in the smoothly varying parts of the images, but there are some difficulties in enlargement at the edges and of details. The paper proposes a hybrid method in which the direct method is combined with the method of Greenspan, with excellent enlargement results at edges and details, after the enlargement of images by estimation of the unknown higher-resolution Laplacian images as in the direct method. It is demonstrated by many application examples that this hybrid method is reasonably simple and is superior numerically and subjectively. © 2001 Scripta Technica, Electron Comm Jpn Pt 2, 84(6): 40–49, 2001 [ABSTRACT FROM AUTHOR]

In this paper, the authors propose a data-dependent weighted average filter (Video-DDWA: Video Data-Dependent Weighted Average) aimed at restoration of dynamic images deteriorated due to Gaussian additive noises. As proposed by the authors, this filter is based on the data-dependent processing, in which the filter weight is varied by multiple local information items derived from the data proximal to the processing point in a still image, with extension of this processing from a spatial filter to a temporal-spatial filter; and then the weight of adjacent frames is determined by detecting presence or absence of motion from the motion information such as new local information. There are several conventional methods of restoration of dynamic images that involve motion compensation with subsequent spatiotemporal filter processing, but they all have limitations as to the filter restoration performance due to noise-affected deterioration of the estimation accuracy of the motion vector. The proposed data-dependent filter using the motion information has among others the following advantages: (1) Because it involves detection of the motion degree at which noise influence is suppressed, it enables restoration of dynamic images featuring a high noise cancellation performance in still areas, without motion deterioration due to filter processing in motion areas—in other words, with processing that does not cause deterioration of movement and (2) the computing load is lower than that with motion-compensated filters. As compared to the conventional methods using motion compensation, this method enables attaining a high restoration performance not only for signals with a low S/N ratio at which the accuracy of the motion compensation estimation vector starts decreasing, but also for signals with a wide range of S/N ratios. The authors demonstrate with various application examples that this method is efficient for restoration of dynamic images. © 2000 Scripta Technica, Electron Comm Jpn Pt 3, 84(4): 1–10, 2001 [ABSTRACT FROM AUTHOR]

Since weighted median filters effective in recovering images belong to the class of stack filters, the authors have proposed a fuzzy weighted median (FWM) filter, which is a weighted median filter defined by a fuzzy Boolean function, and have presented its design method. The design of the FWM filter can be considered in terms of the design of the weight and the design of the fuzzy Boolean function separately. In the design methods developed to date, the fuzzy Boolean functions are sigmoid-type functions and the weights are S-type functions with only the distance from the processing point as a variable, which are approximated and require derivations of four parameters, which is an easy task. Such methods, however, are restricted to the class of designable FWM filters. In this paper, the class of designable FWM filters has been significantly expanded to incorporate nearly all classes of FWM filters by establishing all weights independently and by defining the fuzzy Boolean functions by appropriate functions in addition to the sigmoid-type functions. Thus, a high-performance filter is designed by the filter weight and the fuzzy Boolean function designed for the kinds of added noise for real image processing examples, which change more flexibly as compared with the FWM filters developed in the previous design methods. In addition, a design procedure for realistic cases in which only the images which are targets of processing are known is presented and a design method for an FWM filter, which is effective in practical terms, is presented by showing its performance. © 2000 Scripta Technica, Electron Comm Jpn Pt 3, 84(2): 95–106, 2001 [ABSTRACT FROM AUTHOR]

We propose a method to restore images degraded by additive noise by threshold decomposition filtering. The background regions in many natural images can be interpreted as concentrations of pixels having amplitudes close to certain constant values. These concentrations of pixels are observed as the peaks in a histogram. In this paper, we present a numerical algorithm to determine whether a two-channel filter bank for threshold decomposition is effectively applied to images having one histogram peak, in particular. We also explain how to determine specific thresholds for applicable images. Thus, the application of threshold decomposition is clearly indicated for images having at least one peak in its histogram. Then by applying the results of this study, we demonstrate through specific examples the precise application of threshold decomposition on images having different histogram characteristics. © 2000 Scripta Technica, Electron Comm Jpn Pt 3, 83(10): 17–26, 2000 [ABSTRACT FROM AUTHOR]

We have presented in this paper a new enhancement technique utilizing the high-frequency component information and the edge information sensor defined in Ramponi's method. These kinds of information were used in Ramponi's method, and it is clear that they were effective for the enhancement of noisy images, carrying out enhancement of edges only without enhancing the noise. However, enough extraction is not done because of the way the two kinds of information are considered. Therefore, we proposed in this paper a method based on fuzzy inference, in which the antecedent variables are these two kinds of information and the inference result is the enhancing component. The fuzzy sets for both kinds of information were established experimentally. Through application examples we made clear that we can set the fuzzy sets independently of the kind of images or the additive noise variance, and still greatly improve the enhancement results from Ramponi's method. In this paper we focused on the tuning of the enhancement function ƒ(i,j), whose variables are the edge information sensor defined by Ramponi (square of amplitudes) and the high-frequency component information. Naturally, the scheme of computation for the edge information sensor is still one subject of study, but we leave this topic for further investigation. © 2000 Scripta Technica, Electron Comm Jpn Pt 3, 83(7): 1–11, 2000 [ABSTRACT FROM AUTHOR]

Aiming at the elimination of Gaussian noise and impulsive noise, the authors have proposed the median filter and mean hybrid (MMH) filter, which combines the mean filter, which is useful in eliminating Gaussian noise, with the median filter, which is useful in eliminating impulsive noise. This paper proposes the learning MMH (LMMH) filter with the learning function, where the mean filter and the median filter in the MMH filter are replaced by the FIR filter and the order statistics (OS) filter, respectively, which are more general filters. The LMMH filter is optimized by learning, and the information concerning the position and the order in the training signal are well reflected on the LMMH filter, which improves the accuracy of the signal restoration, compared to the MMH filter. This paper further proposes a method by which the learning signal to be used in the learning of the LMMH filter can be constructed based only on the signal to be processed, which is degraded by the noise. By applying both the LMMH filter and the method of constructing the learning signal, a precise method for learning of the LMMH filter is provided, even in actual situations where the original signal for the signal to be processed is unknown. It is shown through an application example that the LMMH filter obtained by the learning exhibits a stable and better performance than the MMH filter. © 1999 Scripta Technica, Electron Comm Jpn Pt 3, 83(3): 95–107, 2000 [ABSTRACT FROM AUTHOR]

The stack filter is the largest class of nonlinear digital filters, including weighted median filters and morphology filters. The design of the stack filter is reduced to the problem of determination of the Boolean function defining its filter and is divided into design methods of estimation type using a training signal, and design methods maximizing the noise elimination capability under the constraint of preserving a specific configuration. With a view to expanding the class of stack filters, the authors have proposed the fuzzy stack filter, a stack filter defined by the fuzzy Boolean function. Also, for the fuzzy weighted median filter, as the most fundamental fuzzy stack filter, a design method based on the estimation standpoint is provided. In this paper, a new fuzzy stack filter preserving a specific structure is explained. The noise elimination characteristics of the fuzzy stack filter preserving a specific structure and the preservation characteristics of the specific structure under the effect of the noise are clarified. Further, a procedure is presented for deriving a filter suitable for restoration of the degraded images in a wide range without departing from the standpoint of a design method preserving the specific structure (for which empirical information on the signal to be processed cannot be obtained). The effectiveness of the filter obtained by this procedure is presented. © 1999 Scripta Technica, Electron Comm Jpn Pt 3, 83(2): 11–21, 2000 [ABSTRACT FROM AUTHOR]

When edges are to be extracted from an image signal with superposed impulsive additive noises, the noise must be eliminated beforehand. In other words, two independent processing operations must be executed, in the order of noise elimination and edge detection. The elimination of the impulsive noise naturally degrades the edges of the original signal. Consequently, noise elimination and edge detection should be executed in connection with each other. This study tries to realize a new edge detector method, which includes both impulsive noise elimination and edge detection by using fuzzy inference. In the proposed method, the extent of edge detection and the extent of noise elimination can be adjusted continuously by varying the setting of the membership function for the fuzzy inference. This paper presents a detailed guide for setting the membership function through several applied examples and demonstrates the usefulness of the approach. © 1999 Scripta Technica, Electron Comm Jpn Pt 3, 83(1): 61–69, 2000 [ABSTRACT FROM AUTHOR]

The stack filter is the most systematic among the nonlinear filters, including the weighted median filter and the morphology filter. The authors undertook to expand the class of stack filters and to increase the number of degrees of freedom in the design. They employed a fuzzy Boolean function in which the output Boolean function takes a continuous value between “0” and “1,” and proposed a fuzzy stack filter defined by that function. Up to the present, the fuzzy median filter and the fuzzy center weighted median filter have been presented as the most fundamental and simplest fuzzy stack filters. This paper proposes a fuzzy weighted median filter in which the weighted median filter, which is a more general nonlinear filter, is given a fuzzy property through the stack filter. The fuzzy weighted median filter changes continuously from the weighted median filter to the weighted average filter by varying the setting of the fuzzy Boolean function. This implies that the fuzzy weighted median filter has a high noise elimination ability for both impulsive and Gaussian noise. The fuzzy weighted median filter can be designed independently for the weight function and the fuzzy Boolean function. This paper aims at a simple design for the weight function and the fuzzy Boolean function, without losing its general character. The weight is approximated by an S-shaped function with only the distance from the processed point as the parameter, and the fuzzy Boolean function is approximated by a sigmoid function. The design is reduced to the determination of four parameters, which is performed by the LMS algorithm. Through application examples, the properties and the effectiveness of the fuzzy weighted median filter are revealed. © 1999 Scripta Technica, Electron Comm Jpn Pt 3, 82(10): 40–49, 1999 [ABSTRACT FROM AUTHOR]

Nonlinear filters are known to be effective for restoration of image signals subject to additive noise. Among them, the most typical are median filters, and particularly popular are stack filters. Signal processing in the stack filters involves the following three stages: threshold value decomposition, calculation of the Boolean function output at each level, and signal synthesis. The Boolean function is defined by the binary input/output. However, to achieve better filter characteristics and design diversity, the authors considered using fuzzy Boolean functions defined by continuous output values from 0 to 1, rather than conventional Boolean functions. In the current study, the authors performed fuzzification of such common stack filters as the median filter and center weighted median (CWM) filter. Fuzzification was performed by using fuzzy Boolean functions to define the median filter or the CWM filter. The fuzzy Boolean function is derived from fuzzy inference. As a next step, the authors developed a method for fuzzy inference optimization (tuning method). © 1998 Scripta Technica, Electron Comm Jpn Pt 3, 82(2): 83–94, 1999 [ABSTRACT FROM AUTHOR]