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In general, Internet of Things (IoT) devices collect status information or operate according to control commands from other devices. If the safety and reliability of externally accessed devices are compromised, the risk of exposure of internally collected privacy information or abnormal operation of internal devices increases. This paper proposes a method of building a safe smart home environment by pre-blocking devices that may cause a risk by performing mutual safety verification between devices prior to data transmission and reception through the Session Initiation Protocol (SIP) of the home network. Using a Samsung’s commercial smartphone, not a development board to implement the device’s own verification function, and using an open source application and a SIP server providing free service, we established a test environment that is practically applicable and proved the feasibility of the attestation operation of the device. As a result of an operation test involving the capturing of packet data on a communication channel between two devices, it was confirmed that the transmission of parameter data for the actual attestation in SIP/Session Description Protocol packets succeeded without any problems. It was also confirmed that the final verification result of the target device was correctly derived. With the proposed method, it is possible to establish a safe trust relationship between smart home devices and external smart devices or between various IoT devices while also securing the smart home environment by blocking communications with devices that intentionally seek to do harm.

Sewage treatment can remove more than 90% of microplastics, yet large amounts of microplastics are discharged into the ocean. Because microfibers (MFs), primarily generated from the washing of synthetic clothes, are the most abundant type of microplastics among various microplastics detected in the sewage treatment, reducing the amount of MFs entering these treatment plants is necessary. This study aimed to test whether the amount of MFs released from the washing process can be reduced by applying a chitosan pretreatment to the garments before washing. Before the chitosan pretreatment, the polyester clothes released 148 MFs/L, whereas 95% of MFs were reduced after the chitosan pretreatment with 0.7% of chitosan solution. The chitosan pretreatment was applied to other types of garments, such as polyamide and acrylic garments, by treating them with 0.7% of chitosan solution, subsequently, MFs reduced by 48% and 49%, respectively. A morphology analysis conducted after washing revealed that chitosan coating on the polyamide and acrylic were more damaged than on polyester, suggesting that the binding strength of polyamide and acrylic with chitosan was weaker than that of polyester garment. Thus, the results suggested that the chitosan pretreatment might be a promising solution for reducing the amount of MFs generated in the laundering process.

This paper examines the impact of shareholder intervention on investment distortions, which we capture using overinvestment of free cash flow by overconfident CEOs. Using this definition and U.S. data for 1996–2014, our fixed effects and difference-in-difference matching estimation results provide consistent evidence that the threat of potential intervention of shareholders can curb overinvestment by overconfident CEOs. Specifically, firms with greater voting premium and hedge fund activism experience less overinvestment and exhibit lower sensitivity of free cash flow to investment. Such disciplining effects are stronger for firms managed by overconfident CEOs. Overall, our results suggest that shareholder intervention is particularly effective at mitigating overinvestment that is more likely to be distorted.

A DHP (dehumidifying heat pump) has been proposed to save energy consumption in electric vehicles during the dehumidifying and heating operation. Since the mean occupancy rate in a vehicle is less than two people, it is required to optimize the performance of the DHP at low occupancy for an effective operation. The objective of this study is to investigate the performance improvement of a DHP by using the additional waste heat source in electric vehicles with low occupancy. The experiments on the DHP were conducted by varying operating modes, according to various numbers of passengers. Even though the air source DHP in an AL (alternating) mode showed 7.6% lower heating capacity on average, compared to that in the DH (dehumidifying and heating) mode, the COP improvement of the air source DHP in the AL mode against the DH mode was approximately 31% for one passenger. In addition, the dual source DHP in the AL mode showed 15.8% higher heating capacity and 5.2% higher COP on average, compared to the air source DHP in the AL mode.

In electric vehicles, air-conditioning (AC) units and electric heaters have been used for dehumidifying and heating the cabin. However, the air heating process in the electric heater causes higher power consumption due to a lower air temperature entering the electric heater from the sensible cooling in the humidifying process. In this study, a heat pump (HP) and a dual-evaporator heat pump (DHP) combined with a heater are proposed as effective dehumidifying and heating units using waste heat recovery from the dehumidifying process. The performances of the AC, HP, and DHP systems were measured and compared by varying the indoor air wet bulb temperature and compressor speed ratio. Generally, the HP and DHP systems showed superior performance to the conventional AC system in the dehumidifying and heating operation. At the indoor air wet bulb temperature of 13 °C, the DHP system showed 53% and 62% higher specific moisture extraction rate and COP, respectively, than the HP system.

A heat pump has been considered as an alternative to an electric heater to increase the efficiency of the heating unit in electric vehicles. However, the heating performance of a single source heat pump has yet to be improved at low outdoor temperatures. This study investigates the feasibility of a dual source heat pump using both air and waste heat in electric vehicles. The performance of the dual source heat pump was measured at various operation modes: air source-only, waste heat-only and dual heat source. The heating performance of the dual source heat pump was higher than those of the single source heat pumps. In addition, an alternating single mode operation of air source-only and waste heat-only modes was proposed to improve performance at low outdoor air temperatures.

Fluid generated within the sonic or ultrasonic waves are reflected by the wall, while the opposite direction forming a predetermined sound wave to the acoustic standing wave is referred to. In this study, the frequency of 1.0 MHz and 2.0 MHz acoustic standing wave generation module is installed in a continuous particle separation device, the laminar flow of influent, taking into account the hydraulic retention time (HRT) in accordance with changes in particle separation characteristics investigated. Operation of a standing wave in the particle separation device about temperature is increased, but did not significantly affect the formation of standing waves. During operation, the HRT 1 hr frequency 1.0 MHz 2 hr, 4 hr longer as the particle separation efficiency (turbidity) were 64.1%, 70.0%, 74.3% and, 2.0 MHz has 58.0%, respectively, depending on HRT, 61.8%, 70.7% in the respectively. That is, the same frequency, the HRT treatment efficiency is 10% or more, depending on differences in generation and, 1.0 MHz frequency, 2 hr, 2.0 MHz 4 hr at about 70% or more of the processing efficiency can be maintained. Frequency of 1.0 MHz and 2.0 MHz operation at the same time, as a result, HRT 1 hr, 2 hr, 4 hr particle separation efficiency of 63.8%, respectively, 70.6%, 77.6%, rather than the generation of standing waves appear continuous HRT is affecting a lot of particles to separate could know.

We measured chrominance of chrysotile powder using a colorimeter and a luminance meter under different light sources with seven color filters to test feasibility for the real time asbestos detector development. Chrysotile powder was prepared by heating asbestos fabric at 150 °C for 1hr and hydrochloric acid treatment was followed to remove other elements. Refractive index liquid was used as a color changing analyte to observe the change in chrominance of chrysotile. From the measurements, it revealed that a colorimeter was more suitable for the chrysotile detection by the maximum change in chrominance, especially in the short wave length range of blue regions. A luminance meter was not able to separate the difference in chrominance depending on different color and light sources regardless dyeing. It might be due to that reflected light from chrysotile particle was relatively weaker than that from illuminated area. It is our suggestion that the real time monitoring of asbestos in indoor air can be possible using a color sensor, specified to the unique wavelength of dyed chrysotile based on our chrominance data.

Due to its irregular structure, the efficiency of the pelletized fibrous filter can be improved if the target substance is line-shaped. Thus, this study was conducted to examine the applications of the pelletized fibrous filter for biological sewage water with line-shaped particles. Towards this end, the pelletized fibrous filter was applied to advanced treatments in which the particles in the sewage water in the supernatant using solid-liquid separation from the final-settling reservoir was filtered with pelletized fibrous filters. To determine the process efficiency of the filter device, a multiparameter water quality analyzer and a data transmission system were established, which showed the efficient process even at a large distance, as well as the good operational status of the filter device. The pilot plant operation results showed that the concentration of TSS in the influent at 20-75 mg/L was reduced to 0.4-10 mg/L in the processed water. The average processing efficiency was 94.9% between 71.4 and 97.9%, and particularly, that of the suspended solids was very high. The results also showed that 27.2% CODMn, 22.5% T-N, and 30.0% T-P were removed.

In this research, micro-sized copper bump for multi-layered printed circuit board (PCB) was successfully developed using pulse-reverse electroplating method. The electroplating parameters of current density, pulse-reverse ratio and brightener content were optimized for fabrication of suitable micro-bumps. The pulse-reverse electroplated micro-bumps were characterized using various analytical tools and techniques such as optical microscopy, scanning electron microscopy, atomic force microscopy and hydraulic bulge testing. Optical microscope and scanning electron microscope analysis results indicated good electroplating uniformity in the current density range of 1.4–3.0 A/dm 2 , pulse-reverse ratio of 1:1, and brightener concentration of 600 ppm.

In case of cleaning the tap water in Korea, focus has been concentrated on how to improve water quality during the process of purification after taking in original water. However, the interest in human health has been increased, so 'secondary contamination' ,polluted in the process of crossing water reservoir, distributing pipes, indoor water tanks and water pipes after water left a filtration plant, is soared up as an important object of water quality control. Especially the copper pipe for the tap water, its characteristic was acknowledged as a pipe with many merits such as excellent corrosion resistance and easy assembly at the time to lay, is being frequently used in the advanced countries like East Europe, North America, Australia, etc, and is also being used as the material of pipe laying among the pipes for distributing water in Germany and Netherlands. But in case of Korea, the blue or green water problem is found even in the less than 6 year old copper pipes after being installed newly in indoor pipe laying for water distributing that causes to bring about aesthetic distrust to citizens, so the necessity of study is raised to control this situation. In this study tried to control the corrosion and the blue and green water problem happening in the copper pipe using corrosion inhibitors to settle down the various problems available to happen by this problem and suggested an optimized method to manage this situation.

The cost for nonpoint source in urban area tends to increase as it's distanced farther from the pollution source. Thus it's more effective to dispose of the pollution at the pollution source. It becomes more difficult when nonpoint source is flowed into the surface water by stormwater. In case of combined sewer, increasing stormwater on impermeable surface causes the Combined Sewer Overflows (CSOs) containing the high level of pollutants which runs into the water system through the storm overflow diverging tank without treatment process. A huge amount of CSOs is generated instantly and as it carries the pollutants on impermeable surface as well as the deposits in sewage pipe, it's necessary to develop the technology for treatment of CSOs. This study was intended to develop the solid fabric filter which will be suitable for treatment of CSOs and the characteristic and performance of solid fabric filter were evaluated.

Taguchi' design of experiment method and statistical F-test were used to optimize design of tuning forks for use in Qualcomm® mobile station modem (MSM)-3000TM series central processing unit chips of code division multiple access, personal communication system, and global system for mobile communication systems. Design parameters for motional capacitance C1 was further optimized after much trial and error so that as-fabricated resonance frequency values of a tuning fork blank remain almost the same prior to final frequency adjustment plating of the mounted crystals, regardless of packaging pressure change from ambient to designated 6 × 10– 5 Torr. Finite element method modeling was used in conjunction with Taguchi' design of experiment method and, after much trial and error, this enabled selection of essential design parameters to effectively manufacture tuning fork test samples using photolithography with subsequent photoresist spray coating. The tuning fork test samples thus fabricated were characterized and analyzed using Taguchi' method and statistical F-test to evaluate sensitivity of motional capacitance C1 and as-fabricated resonance frequency for various design parameters at ambient to designated packaging pressure of 6 × 10– 5 Torr. Motional capacitance C1 is most sensitive to tine width and tine surface electrode width. Unlike as-fabricated resonance frequency values, motional capacitance values do change with vacuum level of the package. However, tine width asymmetry, electrode thickness and tine tip electrode thickness could be freely adjusted for crystal impedance level without affecting resonance frequency and motional capacitance value. Other design parameters could be adjusted to best suit the manufacturing process.

To realize the voice privacy between CDMA mobile phone and PSTN terminal, the voice frames shall be transmitted transparently between the heterogeneous networks. For satisfying this requirement, we propose the method which transmits voice frames using the CDMA circuit data channel in real time. In this paper we analyze the causes of voice delay which occurs during voice transmission using circuit data channel. And in order to overcome this kind of delay, the technique controlling the TCP control flag and the variable audio block construction algorithm according to the vocoder output rate are proposed. As a result of experimenting by applying the proposed method, we confirmed that the transit delay was improved with about average 70%.

To realize the voice privacy between CDMA mobile phone and TSTN terminal, the voice frames shall be transmitted transparently between the heterogeneous networks. For satisfying this requirement, we propose the method which transmits voice frames by the CDMA circuit data channel in real time. In this paper we analyze the causes of voice delay which occurs during voice transmission by circuit data channel, propose methods which overcome the voice transmission delay and prove proposed methods by the experiment.

Purpose: To compare the clinical outcomes of myectomy, recession, and anterior transposition (AT) of the inferior oblique muscle in congenital unilateral superior oblique palsy. Methods: A total of 40 patients who were followed for longer than three months postoperatively and, who underwent inferior oblique myectomy, recession, or AT were evaluated retrospectively. Results: We compared the result of inferior oblique myectomy, recession, and AT in congenital unilateral superior oblique palsy. The decreased amounts of inferior oblique overaction (IOOA) were 2.240.67, 2.000.76, 3.001.15 for myectomy, recession, and AT, respectively. Improvement of superior oblique underaction was 0.800.66, 0.860.83, 1.000.58, and the changes in hyperdeviation were 10.96PD, 8.25PD, 14.86PD for myectomy, recession, and AT, respectively. There were no significant differences among the surgical methods. The proportion of patients who showed IOOA in the contralateral eye after operation were 20.0% in myectomy, 25.0% in recession, and 57.1% in AT. Conclusions: The efficacies of myectomy, recession, and AT of inferior oblique muscle in the congenital unilateral superior oblique palsies showed no significant differences among methods. The AT group tended to show a larger effect than did the other methods, along with a high development percentage of contralateral eye IOOA. Based on these results, AT of the IO shoud be selectively chosen in more severe cases.

Purpose: To report a case of atypical Miller Fisher syndrome with pupil involvement. Case summary: An 18-year-old woman visited our clinic with a headache and blurred vision. Ophthalmic examination revealed a corrected visual acuity of 20/20 in both eyes, with both pupils dilated to 7.5 mm. There was a loss of light reflex and near reflex in both eyes. Ocular motor examination revealed bilateral abduction, and supraduction limitation, and mild adduction limitation. Neurological examination demonstrated hyporeflexia without ataxia. Brain CT, brain MRI, nerve conduction test, CSF study, and thyroid function tests were normal. The serologic anti-GQ1b IgG test was positive. Conclusions: We confirmed a case of atypical Miller Fisher syndrome with an anti-GQ1 antibody test that had pupil involvement, areflexia, and acute ophthlamoparesis.

Purpose: We report a case of ophthalmic artery occlusion with third nerve paresis in the left eye due to acute occlusion of the left ICA. Case summary: A 37-year-old man visited our emergency room with "black out" in the left eye, headache, and nausea. The corrected visual acuity was 20/25 in the right eye, and hand motion in the left eye. In the left eye, a relative afferent papillary defect was noted, with an intraocular pressure of six mmHg. Twenty prisms of exotropia in the primary position was observed, and ocular motor examination revealed limitations of supraduction, infraduction, and adduction in the left eye, suggesting third nerve palsy of the left eye. Fundus examination revealed a pale retina in the macula of the left eye. Brain MRI demonstrated multifocal faint low densities in the left caudate nucleus as well as the frontal and parietal lobes. CT angiography and four-vessel angiography demonstrated complete occlusion in the proximal part of the left internal carotid artery ICA. After five months the corrected visual acuity of the left eye improved to 20/200. The 20 prism diopters of exotropia persisted, and ocular motor examination revealed only a mild limitation of adduction in the left eye.

Purpose: To report a case of a granular cell tumor in the form of cilliary body tumor. Case Summary: A 42-year-old women visited our clinic with blurred vision of the right eye, which began was 1 month earlier ago. Her medical history was unremarkable. Slit-lamp examination revealed a ciliary body tumor and complicated cataract due to a mass lesion. For treatment, an excisional biopsy of the ciliary body tumor and phacoemulsification were performed. The pathologic finding confirmed the diagnosis of a granular cell tumor. There was no evidence of a recurrent lesion of the tumor at the 6-month postoperative follow-up. Conclusions: We confirmed a granular cell tumor in the form of a cilliary body tumor based on pathologic findings.