Search

The postoperative hypofractionated intensity-modulated radiation therapy (POHIM-RT) trial is a phase II study to evaluate toxicity following hypofractionated intensity modulated radiation therapy (IMRT) for cervical cancer. This study describes the results of a benchmark procedure for RT quality assurance of the POHIM-RT trial. Six participating institutions were provided computed tomography for RT planning and an IMRT plan for a sample and were instructed to delineate volumes, create a treatment plan and quality assurance (QA) plan, and submit the results of all procedures. The inter-institutional agreements on RT volume and plan results were evaluated using the kappa value and dice similarity coefficients. The simultaneous truth and performance level estimation (STAPLE) method was employed to generate a consensus target volume. The treatment volumes, organs-at-risk volumes, and results of the RT plan and QA reported by the institutions were acceptable and adhered well to the protocol. In terms of clinical target volume (CTV) delineation, there were differences between the institutions, particularly in vaginal cuff and paracolpium subsites. Consensus CTV was generated from the collected CTVs with the STAPLE method. The participating institutions showed considerable agreement regarding volume, dose and QA results. To improve CTV agreement in CTV, we provided feedback with images of the consensus target volume and detailed written guidelines for specific subsites that were the most heterogeneous.

An optical see-through (OST) display is affected more severely by ambient light than any other type of displays when placed in an outdoor environment with bright illuminance because of its transparency and thus, its inherent color distortion can worsen. It is hard to directly apply existing gamut mapping methods to an OST display because of its morphological gamut characteristic and the effect of ambient light. In this paper, we propose a new robust gamut mapping method which works against bright ambient light. The process is divided into two steps: lightness mapping (LM) and chroma reproduction. LM aligns the lightness level of sRGB gamut with OST gamut and partitions the region of OST gamut based on the relative size of the sRGB gamut and its lightness value. The second step (chroma reproduction) determines an appropriate chroma reproduction method (gamut compression or extension) and a proper direction for gamut mapping based on the characteristics of each region in order to minimize the effects of ambient light. The quality of color reproduction is qualitatively and quantitatively evaluated based on accurate measurements of the displayed colors. It has been experimentally confirmed that the proposed gamut mapping method can reduce color distortion more than the existing parametric gamut mapping algorithms.

Nowadays, cameras embedded in smartphones can take high resolution photographs that can be used to analyze skin conditions without using specialized equipments. In shooting photographs with a smartphone, it is difficult to maintain a uniform shooting distance. Therefore, it is essential to adapt a skin analysis method to the shooting distance. In this paper, we focus on a pore detection algorithm that is adaptive to the camera distance. We develop a relationship model between the shooting distance and the appropriate size of the pore detection mask. In addition, we propose a method to estimate the normalized pore size (i. e. pore size at a standard shooting distance). We conducted experiments on skin images taken from different shooting distances. It was verified that the proposed method can achieve more accurate pore detection result, close to those from skin images taken at a standard shooting distance.

In Optical See-Through (OST) displays, the chroma component in color space is often distorted. OST displays appear to have a uniquely different gamut feature compared with conventional color devices. In this paper, we proposed a novel two-step gamut mapping method for OST displays. The conventional CARISMA (Color Appearance Research for Interactive System Management and Application) algorithm is extended straightforwardly, and its process is divided into two separate steps (lightness mapping and chroma compression) by reflecting the characteristics of the newtype OST. We confirmed experimentally that the proposed gamut mapping method can reduce color distortion better than the existing CARISMA.

Transparency of optical see-through head-mounted displays (OST-HMDs) makes them suffer from background blending. Existing works have tackled this problem by color correction, but have not addressed how to estimate the background color accurately. In this paper, we apply colorimetric estimation to the subtraction compensation for background blending. Moreover, we propose an optimization framework that trades-off the overall color distortion and clipping to achieve the optimal color correction, constrained to keeping image structures and details.

In an augmented reality scenario, the perceived image of OST-HMD contains color distortion due to background color blending. In order to reduce color blending, accurate estimation of background color is necessary. In this paper, we perform colorimetric estimation of background using camera images, via local linear regression. Using the estimated background color, virtual image is compensated. Experimental results show that the proposed colorimetric background estimation closely estimates the background color within an error of 1.635 degrees, and that the color blending reduction error typically falls under 5 degrees in most cases.

A fluidized bed reactor made of quartz with 0.055 m i.d. and 0.65 m in height was employed for the thermocatalytic decomposition of methane to produce CO2 free hydrogen. The fluidized bed reactor was proposed in order to overcome the reactor plugging problem due to carbon deposition, which was resulted in the shut-down of the fixed bed reactor system. Several kinds of activated carbons were employed as the catalyst to examine the reaction activity. The experimental results in this study were compared with that of fixed bed reactor. The reaction rate and deactivation of carbon catalyst were similar to that of lab scale fixed bed reactor system. The deactivation due to carbon deposition was verified with the SEM images of fresh and used carbon catalysts. The effects of gas velocity, reaction temperature and particle size on the reaction rates were also investigated. From the experimental results of this study, the optimum operating conditions for fluidized bed were also determined.

Purpose To assess the feasibility and therapeutic benefits of a combination of external beam radiotherapy (EBRT) and high-dose-rate intraluminal brachytherapy (ILBT) for treating patients with inoperable carcinoma of the extrahepatic bile ducts. Methods and materials Of 31 patients who received RT at the Yonsei Cancer Center, Yonsei University College of Medicine in Seoul, Korea between 1986 and 1995, 17 patients underwent EBRT alone (Group 1) and 14 patients were treated with EBRT in combination with high-dose-rate ILBT (Group 2). After external drainage, EBRT was delivered with a total dose ranging from 36 to 55 Gy (median 50.4) in both groups. High-dose-rate ILBT for the patients in Group 2 was performed using a high-intensity 192 Ir source (Gamma-med remote afterloading system) within the expandable intrabiliary prosthesis (Gianturco stent), inserted transhepatically at the site of the obstruction. The radiation dose of the high-dose-rate ILBT was prescribed at 1.5 cm from the center of the source with a single daily dose of 5 Gy to a total of 15 Gy given in three fractions. The response rate, patterns of treatment failure, treatment morbidity, and survival data in the two groups were compared. Results Although locoregional recurrence was the most common pattern of failure in both groups, no statistically significant difference was found in the recurrence rates between those who did and did not receive ILBT (53% for Group 1 vs. 36% for Group 2; p > 0.05). However, a prolongation of the median time to tumor recurrence was observed in the Group 2 patients (5 months for Group 1 vs. 9 months for Group 2; p = 0.06). When the EBRT dose delivered was >50 Gy, most patients experienced various degrees of GI symptoms, but the frequency of radiation-induced complications in the two groups was similar. No enhancement in treatment morbidity was attributed to the addition of high-dose-rate ILBT to EBRT. With a median follow-up of 12 months, the overall actuarial 2-year survival rate for Group 2 patients was significantly better than that for Group 1 patients (0% for Group 1 vs. 21% for Group 2; p = 0.015). Conclusion Given these observations, we believe that the combined use of EBRT and high-dose-rate ILBT is a beneficial, relatively safe, and effective method of improving the treatment outcome in selected patients with inoperable carcinoma of the extrahepatic bile ducts.

Monitoring of the cutting force signals in turning process has been well emphasized for unmanned machining. Although the cutting force can be directly measured by a tool dynamometer, direct sensing in factory environment is not feasible because of high cost and limitations in setup. In this paper two indirect cutting force estimation systems are developed based on the measured output power and on the calculated input power signals, respectively. These estimation systems consider the cutting force as a disturbance input to the spindle drive and estimate the cutting force based on the inverse dynamic model. The inverse dynamic model represents the dynamic relation between the cutting force, the motor torque and the motor power. The proposed estimation systems are realized on a CNC lathe and their estimation performance is evaluated experimentally.

Monitoring of the cutting force signals in a cutting process has been well emphasized in machine tool communities. Although the cutting force can be directly measured by a tool dynamometer, this method is not always feasible because of high cost and limitations in setup. In the paper an indirect cutting force monitoring system is developed so that the cutting force in a turning process is estimated based on an AC spindle drive model. This monitoring system considers the cutting force as a disturbance input to the spindle drive and estimates the cutting force based on the inverse dynamic model. The inverse dynamic model represents the dynamic relation between the cutting force, the motor torque and the motor power. The proposed monitoring system is realized on a CNC lathe and its estimation performance is evaluated experimentally.

Background: Most lung cancer patients receive systemic chemotherapy at an advanced stage disease. Cisplatin-based chemotherapy is the main regimen for treating advanced lung can cer. Recently, autophagy has become an important mechanism of cellular adaptation under starvation or cell oxidative stress. The purpose of this study was to determine whether or not autophagy can occurred in cisplatin-treated lung cancer cells.Methods: H460 cells were incubated with RPMI 1640 and treated in 5 μM or 20 μM cisplatin concentrations at specific time intervals. Cells surviving cisplatin treatment were measured and compared using an MTT cell viability assay to cells that underwent apoptosis with autophagy by nuclear staining, apoptotic or autophagic related proteins, and autophagic vacuoles. The development of acidic vascular organelles was using acridine orange staining and fluorescent expression of GFP-LC3 protein in its transfected cells was observed to evaluate autophagy.Results: Lung cancer cells treated with 5 μM cisplatin-treated were less sensitive to cell death than 20 μM cisplatin-treated cells in a time-dependent manner. Nuclear fragmentation at 5 μM was not detected, even though it was discovered at 20 μM. Poly (ADP-ribose) polymerase cleavages were not detected in 5 μM within 24 hours. Massive vacuolization in the cytoplasm of 5 μM treated cells were observed. Acridine orange stain-positive cells was increased according in time-dependence manner. The autophagosome-incorporated LC3 II protein expression was increased in 5 μM treated cells, but was not detected in 20 μM treated cells. The expression of GFP-LC3 were increased in 5 μM treated cells in a time-dependent manner.Conclusion: The induction of autophagy occurred in 5 μM dose of cisplatin-treated lung cancer cells.Key Words: Autophagy; Cisplatin; Lung Neoplasms