• Journal of Korean Society of Environmental Engineers
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• v.31 no.11
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• pp.1007-1018
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• 2009

Hydrocyclone is widely used in industry, because of its simplicity in design, high capacity, low maintenance and operational cost. The separation action of a hydrocyclone treating particulate slurry is a consequence of the swirling flow that produces a centrifugal force on the fluid and suspended particles. In spite of hydrocyclone have many advantage, the application for treatment of urban stormwater case study were rare. We conducted a laboratory scale study on treatable potential of micro particles using hydrocyclone filter (HCF) that was a combined modified hydrocyclone with perlite filter cartridge. Since it was not easy to use actual storm water in the scaled-down hydraulic model investigations, it was necessary to reproduce ranges of particles sizes with synthetic materials. The synthesized storm runoff was made with water and addition of particles; ion exchange resin, road sediment, commercial area manhole sediment, and silica gel particles. Experimental studies have been carried out about the particle separation performance of HCF-open system and HCF-closed system. The principal structural differences of these HCFs are underflow zone structure and vortex finder. HCF was made of acryl resin with 120 mm of diameter hydrocyclone and 250 mm of diameter filter chamber and overall height of 800 mm. To determine the removal efficiency for various influent concentrations of suspended solids (SS) and chemical oxygen demand (COD), tests were performed with different operational conditions. The operated maximum of surface loading rate was about 700 $m^3/m^2$/day for HCF-open system, and 1,200 $m^3/m^2$/day for HCF-closed system. It was found that particle removal efficiency for the HCF-closed system is better than the HCF-open system under same surface loading rate. Results showed that SS removal efficiency with the HCF-closed system improved by about 8~20% compared with HCF-open system. The average removal efficiency difference for HCF-closed system between measurement and CFD particle tracking simulation was about 4%.

• Tuberculosis and Respiratory Diseases
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• v.42 no.1
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• pp.25-34
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• 1995

Background: Endobronchial tuberculosis is classified into 7 subtypes as fibrostenotic type, edematous-hyperemic type, actively caseating type, tumorous type, ulcerative type, granular type and nonspecific bronchitic type by bronchoscopic features, and we make a prospective study to follow up how bronchoscopic findings change during treatment-course in each subtype of active endobronchial tuberculosis. Methods: We planned to do follow-up bronchoscopic examination every month until there was no significant change in endobronchial lesion, then every 3 months and at the end of the treatment in each patient with biopsy proven endobronchial tuberculosis from May, 1990 to August, 1993. Results: 1) This study included 66 cases, but bronchoscopic follow-up was completed as scheduled in 47 cases. 2) In actively caseating and edematous-hyperemic type, bronchostenosis occurred within 2 or 3 months of treatment in about 2/3 of total cases. 3) In fibrostenotic type, bronchostenosis did not improve in spite of the treatment. 4) In tumorous type, the changes in bronchoscopic findings were unpredictable because new lesions occured on other sites even 4 or 6 months after treatment in 2 cases and the size of initial mass increased 6 months after treatment in 1 case (among 7 cases). 5) Granular and nonspecific bronchitic type improved without significant sequelae within 2 or 3 months of treatment. Conclusion: It may be necessary to follow up the patient with bronchoscopy repeatedly 2 or 3 months after starting treatment in active endobronchial tuberculosis, and it is better to perform bronchoscopic examination at 6 months of treatment, especially in patients with tumorous type because there is possibility that new endobronchial lesion occurs. Aggressive therapeutic modalities such as stent-insertion, laser therapy or electrocautery should be considered to prevent bronchostenosis in cases with granulation tissue, fibrostenotic and tumorous types of endobronchial tuberculosis.

• The Korean Journal of Food And Nutrition
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• v.14 no.1
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• pp.34-39
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• 2001

The purpose of this study was to examine physical properties of the addition of green tea powder on bread flour and dough rheology of white pan bread. Three levels(0.1, 0.5 and 1.0% ) of each green tea powder with bread flour were tested for their effects in dough mixing using rapid disco analyzer, alveogram and farinogram. Addition of green tea powder tended to reduce initial pasting temperature and increase peak viscosity, break down and set back. L(extensibility) and G(swelling index) value in alveogram showed decrement with increasing green tea powder. These meant that the volume of white pan bread would show same tendency. The use of green tea powder increased consistency and water absorption of the bread flour but decreased development time, salability and degree of softening on farinogram. White pan bread with green tea powder had higher value of hardness and springness than without it. Sensory evaluation determined that the white pan bread with 0.5% green tea powder had the highest score.

• Journal of the Microelectronics and Packaging Society
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• v.26 no.4
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• pp.75-82
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• 2019

Flexible solar cells have attracted enormous attention in recent years due to their wide applications such as portable batteries, wearable devices, robotics, drones, and airplanes. In particular, the demands of the flexible silicon and compound semiconductor solar cells with high efficiency and high reliability keep increasing. In this study, we fabricated a flexible InGaP/GaAs double-junction solar module. Then, the effects of the wind speed and ambient temperature on the operating temperature of the solar cell were analyzed with the numerical simulation. The temperature distributions of the solar modules were analyzed for three different wind speeds of 0 m/s, 2.5 m/s, and 5 m/s, and two different ambient temperature conditions of 25℃ and 33℃. The flexibility of the flexible solar module was also evaluated with the bending tests and numerical bending simulation. When the wind speed was 0 m/s at 25 ℃, the maximum temperature of the solar cell was reached to be 149.7℃. When the wind speed was increased to 2.5 m/s, the temperature of the solar cell was reduced to 66.2℃. In case of the wind speed of 5 m/s, the temperature of the solar cell dropped sharply to 48.3℃. Ambient temperature also influenced the operating temperature of the solar cell. When the ambient temperature increased to 33℃ at 2.5 m/s, the temperature of the solar cell slightly increased to 74.2℃ indicating that the most important parameter affecting the temperature of the solar cell was heat dissipation due to wind speed. Since the maximum temperatures of the solar cell are lower than the glass transition temperatures of the materials used, the chances of thermal deformation and degradation of the module will be very low. The flexible solar module can be bent to a bending radius of 7 mm showing relatively good bending capability. Neutral plane analysis was also indicated that the flexibility of the solar module can be further improved by locating the solar cell in the neutral plane.

• Radiation Oncology Journal
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• v.21 no.3
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• pp.238-244
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• 2003

Purpose: The Planning of High-Dose-Rate (HDR) brachytherapy treatments are becoming individualized and more dependent on the treatment planning system. Therefore, computer software has been developed to perform independent point dose calculations with the integration of an isodose distribution curve display into the patient anatomy images. Meterials and Methods: As primary input data, the program takes patients'planning data including the source dwell positions, dwell times and the doses at reference points, computed by an HDR treatment planning system (TPS). Dosimetric calculations were peformed in a $10\times12\times10\;Cm^3$ grid space using the Interstitial Collaborative Working Group (ICWG) formalism and an anisotropy table for the HDR Iridium-192 source. The computed doses at the reference points were automatically compared with the relevant results of the TPS. The MR and simulation film images were then imported and the isodose distributions on the axial, sagittal and coronal planes intersecting the point selected by a user were superimposed on the imported images and then displayed. The accuracy of the software was tested in three benchmark plans peformed by Gamma-Med 12i TPS (MDS Nordion, Germany). Nine patients'plans generated by Plato (Nucletron Corporation, The Netherlands) were verified by the developed software. Results: The absolute doses computed by the developed software agreed with the commercial TPS results within an accuracy of $2.8\%$ in the benchmark plans. The isodose distribution plots showed excellent agreements with the exception of the tip legion of the source's longitudinal axis where a slight deviation was observed. In clinical plans, the secondary dose calculations had, on average, about a $3.4\%$ deviation from the TPS plans. Conclusion: The accurate validation of complicate treatment plans is possible with the developed software and the qualify of the HDR treatment plan can be improved with the isodose display integrated into the patient anatomy information.

• Journal of Biomedical Engineering Research
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• v.25 no.3
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• pp.171-182
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• 2004

This study investigates the biomechanical efficacies of vertebroplasty which is used to treat vertebral body fracture with bone cement augmentation for osteoporotic patients using image and finite element analysis. Simulated models were divided into two groups: (a) a vertebral body, (b) a functional spinal unit(FSU). For a vertebral body model, the maximum axial displacement was investigated under axial compression to evaluate the effect of structural integrity. The stiffness of each FE model simulated was normalized by the stiffness of intact model. In the case of FSU model, 3 types of compression fractures were formulated to assess the influence on spinal curvature changes. The FSU models were loaded under compressive pressure to calculate the change of spinal curvature. The results according to the various factors suggest that vertebroplasty has the biomechanical efficacy of the increment of structural reinforcement in a patient who has relatively high level of BMD and a patient with the amount of 15％, PMMA injection of the cancellous bone volume. The spinal curvatures after compression fracture simulation vary from 9$^{\circ}$ to 17$^{\circ}$ of kyphosis compared to that the spinal curvature of normal model was -2.8$^{\circ}$ of lordosis. These spinal curvature changes cause the severe spinal deformity under the same loading. As the degree of compressive fracture increases the spinal deformity also increases. The results indicate that vertebroplasty has the increasing effect of the structural integrity regardless of the amount of PMMA or BMD and the restoration of decreased vertebral body height may be an important factor when the compressive fracture caused the significant height loss of vertebral body.

• Korean Journal of Psychosomatic Medicine
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• v.11 no.1
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• pp.77-88
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• 2003

Objectives: The purpose of this study was to compare reliability and validity of three Korean versions of the 20-item Toronto Alexithymia scale and to confirm the most reliable and validated Korean translation of the 20-item Toronto Alexithymia Scale for both clinical and research purpose in Korea. The first one was a Korean version of the 20-Item Toronto Alexithymia Scale developed by Lee YH et al in 1996 which was designated as TAS-20K(1996) in this study. This scale had a problem with one item due to the cultural difference regarding the word 'analyzing' between western culture and Korean culture. The second one was the revised version of TAS-20K(1996) on that point by Lee YH et al in 1996 without validation which was designated as TAS-20K(2003) in this study. The third one was a 23-item Korean version developed by Sin HG and Won HT in 1997, which was somewhat different from the 20-item Toronto Alexithymia Scale(TAS-20) in the number of total item, the content of some items and the scoring method. This scale was designated as S-TAS here. Methods: 408 medical students were tested with one scale composed of all the different items randomly arranged from the three versions. We evaluated goodness-of-fit and Cronbach $\alpha$ coefficients of three scales for reliability. We used confirmatory factor analysis to compare validity. Results: TAS-20K(2003) showed that it had better internal consistency than TAS-20K(1996), which implied that the cultural difference should be considered in the Korean translation. Both TAS-20K(2003) and S-TAS replicated three-factor structures and had adequacy of fit, good internal consistency and acceptable validity. However, S-TAS had one item with poor item-factor correlation and didn't show high correlation between item 2 and factor 1 as before in 1997. Conclusion: Although S-TAS had added 3 items and changed the content of two items, it didn't show better reliability and validity than TAS-20K(2003). Therefore it is proposed to use TAS-20K (2003) as the Korean version of the 20-item Toronto Alexithymia Scale(TAS-20K) for international communication of results of Alexithymia research. It has good internal consistency and validity and maintains original items, the same construct and scoring method as the 20-item Toronto Alexithymia Scale.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.180-185
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• 2003

The increase of traffic over a bridge has been emerged as one of the most severe problems in view of bridge maintenance, since the load effect caused by the vehicle passage over the bridge has brought out a long-term damage to bridge structure, and it is nearly impossible to maintain operational serviceability of bridge to user's satisfactory level without any concern on bridge maintenance at the phase of completion. Moreover, bridge maintenance operation should be performed by regular inspection over the bridge to prevent structural malfunction or unexpected accidents front breaking out by monitoring on cracks or deformations during service. Therefore, technical breakthrough related to this uninterested field of bridge maintenance leading the public to the turning point of recognition is desperately needed. This study has the aim of development on automated inspection system to lower surface of bridge superstructures to replace the conventional system of bridge inspection with the naked eye, where the monitoring staff is directly on board to refractive or other type of maintenance .vehicles, with which it is expected that we can solve the problems essentially where the results of inspection are varied to change with subjective manlier from monitoring staff, increase stabilities in safety during the inspection, and make contribution to construct data base by providing objective and quantitative data and materials through image processing method over data captured by cameras. By this system it is also expected that objective estimation over the right time of maintenance and reinforcement work will lead enormous decrease in maintenance cost.

• 한국지구물리탐사학회:학술대회논문집
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• 2005.09a
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• pp.125-153
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• 2005

It has been widely known that the seismic piezo-cone penetration test (SCPTU) is one of the most useful techniques for investigating the geotechnical characteristics including dynamic soil properties. As the practical applications in Korea, SCPTU was carried out at two sites in Busan and four sites in Incheon, which are mainly composed of alluvial or marine soil deposits. From the SCPTU waveform data obtained from the testing sites, the first arrival times of shear waves were and the corresponding time differences with depth were determined using the cross-over method, and the shear wave velocity profiles (VS) were derived based on the refracted ray path method based on Snell's law and similar to the trend of cone tip resistance (qt) profiles. In Incheon area, the testing depths of SCPTU were deeper than those of conventional down-hole seismic tests. Moreover, for the application of the conventional CPTU to earthquake engineering practices, the correlations between VS and CPTU data were deduced based on the SCPTU results. For the empirical evaluation of VS for all soils together with clays and sands which are classified unambiguously in this study by the soil behavior type classification Index (IC), the authors suggested the VS-CPTU data correlations expressed as a function of four parameters, qt, fs, $\sigma$, v0 and Bq, determined by multiple statistical regression modeling. Despite the incompatible strain levels of the down-hole seismic test during SCPTU and the conventional CPTU, it is shown that the VS-CPTU data correlations for all soils clays and sands suggested in this study is applicable to the preliminary estimation of VS for the Korean deposits and is more reliable than the previous correlations proposed by other researchers.

• Archives of design research
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• v.19 no.5 s.67
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• pp.85-94
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• 2006

In the 2000s, character animation technique is used at domestic TV character animation ads of diverse items displaying new character patterns and expression techniques of a high level. This study intends to identify the characteristics of TV character animation ads based ell character aesthetic theory and advertising rhetoric theory, and based on these findings, analyze trend and stream of expression in TV character animation ads by examining and classifying advertisements released in the past four years by items, character patterns and expression techniques. The results showed that TV character animation ads have been concentrated on confectionery, beverages and foods in the past, but the items have been diversified through the years. With reference to character patterns, personal and animal characters had made the main pattern, but recently product, virtual and composite characters are on the increase. In expression techniques, cell animation technique was found to be the most frequently used technique, which was followed by full-3D, cell and live action, cell and 3D and the clay animation technique. A trend like this suggests that TV character animation advertising items will continue to increase in line with the participation level of targets. In the meantime, personal and animal characters will continue to make the leading character pattern, while virtual and composite character patterns emerge in new forms. In expression techniques, live action combined with 30 technique and techniques using new expression materials will appear with cell animation technique as a central figure. As a whole, Korean character animation advertisement is expected to keep on growing to a new dimension in the aspect of items, character patterns and expression technique.