• Journal of KIBIM
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• v.12 no.4
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• pp.19-31
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• 2022

With the development of 3D-based CAD (Computer Aided Design), attempts at freeform building design have expanded to small and medium-sized buildings in Korea. However, a standardized system for continuous utilization of shape data and BIM conversion process implemented with 3D-based NURBS is still immature. Without accurate review and management throughout the Freeform building project, interference between members occurs and the cost of the project increases. This is very detrimental to the project. To solve this problem, we proposed a continuous utilization process of 3D shape information based on BIM parameters. Our process includes algorithms such as Auto Split, Panel Optimization, Excel extraction based on shape information, BIM modeling through Adaptive Component, and BIM model utilization method using ID Code. The optimal cutting reference point was calculated and the optimal material specification was derived using the Panel Optimization algorithm. With the Adaptive Component design methodology, a BIM model conforming to the standard cross-section details and specifications was uniformly established. The automatic BIM conversion algorithm of shape data through Excel extraction created a BIM model without omission of data based on the optimized panel cutting reference point and cutting line. Finally, we analyzed how to use the BIM model built for automatic conversion. As a result of the analysis, in addition to the BIM utilization plan in the general construction stage such as visualization, interference review, quantity calculation, and construction simulation, an individual management plan for the unit panel was derived through ID data input. This study suggested an improvement process by linking the existing research on atypical panel optimization and the study of parameter-based BIM information management method. And it showed that it can solve the problems of existing Freeform building project.

• Journal of Korea Society of Industrial Information Systems
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• v.14 no.4
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• pp.1-7
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• 2009

This paper presents a process routing (PR) algorithm with multiple objectives. PR determines the optimum sequence of operations for transforming a raw material into a completed part within the available machining resources. In any computer aided process planning (CAPP) system, selection of the machining operation sequence is one of the most critical activities for manufacturing a part and for the technical specification in the part drawing. Here, the goal could be to generate the sequence that optimizes production time, production cost, machine utilization or with multiple these criteria. The Pareto Stratum Niche Cubicle (PS NC) GA has been adopted to find the optimum sequence of operations that optimize two conflicting criteria; production cost and production quality. The numerical analysis shows that the proposed PS NC GA is both effective and efficient to the PR problem.

• Journal of Biomedical Engineering Research
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• v.44 no.3
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• pp.211-217
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• 2023

Recently, many studies have introduced artificial intelligence systems in the surgical process to reduce the incidence and mortality of complications in patients. Bleeding is a major cause of operative mortality and complications. However, there have been few studies conducted on detecting bleeding in surgical videos. To advance the development of deep learning models for detecting intraoperative hemorrhage, three models have been trained and compared; such as, YOLOv5, RetinaNet50, and RetinaNet101. We collected 1,016 bleeding images extracted from five surgical videos. The ground truths were labeled based on agreement from two specialists. To train and evaluate models, we divided the datasets into training data, validation data, and test data. For training, 812 images (80%) were selected from the dataset. Another 102 images (10%) were used for evaluation and the remaining 102 images (10%) were used as the evaluation data. The three main metrics used to evaluate performance are precision, recall, and false positive per image (FPPI). Based on the evaluation metrics, RetinaNet101 achieved the best detection results out of the three models (Precision rate of 0.99±0.01, Recall rate of 0.93±0.02, and FPPI of 0.01±0.01). The information on the bleeding detected in surgical videos can be quickly transmitted to the operating room, improving patient outcomes.

• Korean Journal of Exercise Nutrition
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• v.13 no.2
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• pp.101-107
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• 2009

The objectives of this study were to investigate 1) the nutritional knowledge, 2) the use of nutritional supplements, and 3) nutrient intakes of male elite bodybuilders (n=20). Participants carried out a comprehensive survey, anthropometric assessment, and 1 day food record. Daily nutrient intakes of the subjects were analyzed using Computer Aided Nutritional Analysis Program (Can-pro 3.0). The mean age of the subjects was 23.4 years. The mean duration of exercise was 5.3 years. The average scores of nutritional knowledge were 71.0%. The subjects were gathered nutrition information from nutrition book (65%), mass communication (50%), friends (50%) and coach (30%) in order. Ninety percentage of the subjects reported that they were taking nutritional supplements. Major reasons for taking nutritional supplements were to improve performance and to build-up muscle. The most frequently taken nutritional supplements were protein powder (85%), multivitamin/mineral (75%), BCAA (60%) and glutamine (55%) in order. The average daily energy intakes of the subjects were 4,248.7 kcal. The mean intake of protein was 370.3 g/day (3.93 g/kg BW). The ratio of total energy intake from carbohydrate, protein and lipid was 51 : 34 : 15. The intakes of most vitamin and minerals through food and nutrition supplements were much higher than those of each nutrient of the RDAs. Especially, vitamin B complex and vitamin C intakes were ranged from 500 to 3,000% of KNHNES. More research needs to be conducted to determine the optimal amounts of carbohydrates, protein, lipid and micro-nutrients for the bodybuilders.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.5
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• pp.534-540
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• 2013

Interest of the hand effect on the electromagnetic wave are internationally increasing with the increase of the use of the mobile phone. IEC TC106(International Electrotechnical Commission, Technical Committee 106) promotes international research exchange program in order to reflect the effect of human hands in the standard assessment method of human exposure dosimetry by the electromagnetic wave of mobile phones. Since current commercialized hand phantom is manufactured by taking into account the average size of westerners and provides only one grip posture, it imposes many restrictions on the accurate SAR measurement. Therefore, the development of proper hand phantom accounting for domestic situation and various grip posture capability is essential in order to analyze the accurate effect of human hand on the exposure estimation. In this paper, a jelly hand phantom suitable for Korean was manufactured with various grip posture capability at 835 MHz and 1,800 MHz bands. Although the tolerances of permittivity and conductivity of the manufactured hand phantom are with ${\pm}10%$ each, it was much less than CTIA(Cellular Telecommunication Industry Association) tolerance of ${\pm}20%$ at both bands. Its 3D CAD(3 Dimensional Computer Aided Design) file which was developed can be utilized for the simulation of human hand effect on SAR measurement of mobile phones. The findings in this study can be utilized for the analysis of human hand effect on SAR measurement of a mobile phone.

• Korean Journal of Materials Research
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• v.8 no.8
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• pp.744-750
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• 1998

Unlike common device, MEMS(micro-electro-mechanical system) device consists of very small mechanical structures which determine the performance of the device. Because of its small mechanical structure inside. MEMS device is very sensitive to thermal stress caused by CTE(coefficient of thermal expansion) mismatch between its components. Therefore, its characteristics are affected by material properties. process temperature. and dimensions of each layer such as chip, adhesive and substrate. In this study. we investigated the change of the thermal stress in the chip attached to a substrate. With computer-aided finite element method (FEM), the computer simulation of the thermal stress was conducted on variables such as bonding material, process temperature, bonding layer thickness and die size. The commercial simulation program, ABAQUS ver5.6, was used. Subsequently 3-layer test samples were fabricated, and their degree of bending were measured by 3-D coordinate measuring machine. The experimental results were in good agreement with the simulation results. This study shows that the bonding layer could be the source of stress or act as the buffer layer for stress according to its elastic modulus and CTE. Solder adhesive layer was the source of stress due to its high elastic modulus, therefore high compressive stress was developed in the chip. And the maximum tensile stress was developed in the adhesive layer. On the other hand, polymer adhesive layer with low elastic modulus acted as buffer layer, and resulted in lower compressive stress. The maximum tensile stress was developed in the substrate.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.4
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• pp.1-6
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• 2008

In this paper, millimeter-wave broadband MHEMT (Metamorphic High Electron Mobility Transistor) cascode amplifiers were designed and fabricated. The $0.1{\mu}m$ InGaAs/InAlAs/GaAs MHEMT was fabricated for cascode amplifiers. The DC characteristics of MHEMT are 670 mA/mm of drain current density, 588 mS/mm of maximum transconductance. The current gain cut-off frequency($f_T$) is 139 GHz and the maximum oscillation frequency($f_{max}$) is 266 GHz. To prevent oscillation of the designed cascode amplifiers, a parallel resistor and capacitor were connected to the drain of common gate device. By using the CPW (Coplanar Waveguide) transmission line, the cascode amplifier was designed and matched for the broadband characteristics. The designed amplifier was fabricated by the MHEMT MMIC process that was developed through this research. As the results of measurement, the amplifier was obtained 3 dB bandwidth of 50.37 GHz between 20.76 to 71.13 GHz. Also, this amplifier represents the S21 gain with the average 7.07 dB gain in bandwidth and the maximum gain of 10.3 dB at 30 GHz.

• Journal of Animal Science and Technology
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• v.48 no.6
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• pp.777-784
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• 2006

This study was designed to investigate between the semen characteristics and sperm chromatin structure in boar with different farrowing rates and relationship between fertility by AI and results of sperm chromatin structure assay (SCSA). The CASA (computer-aided sperm analysis) and SCSA were performed with liquid semen in boars. The all SCSA parameters based on the farrowing rates by AI were significantly differ (P<0.05). The significant negative correlations (P<0.05) were observed between all SCSA parameters and farrowing rate obtained by AI in the field. In conclusion, these results suggest that the sperm parameters evaluated in these studies may be useful indicators to predict the fertility by AI.

• Journal of dental hygiene science
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• v.18 no.2
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• pp.113-123
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• 2018

The purpose of this study to review clinicians and educators on required communication education factors of dental hygienists using qualitative research by focus group interview. The participants were dentists, dental hygienists and professors. A questionnaire was developed on communication education to collect data. The collated data derived concepts related to communication education. After transferring the data, were analyzed by open coding and axial coding using computer-aided qualitative data analysis software. Focus group emphasized that higher education on communication should be preceded before they are put into the clinical field. However, the dental hygienist emphasized experiential education in the clinical field, the professor emphasized additional education for continuity of communication education even after graduation. Besides, focus group emphasized role play, and the professor required that the standardization of the dental communication training courses objectives and role play modules and the education environment infrastructure should be established to implement communication education efficiently. The categories of communication education stated in the focus group were time and method for the dental communication training courses, dental communication training courses standardization and educational environment, of evaluation of communication competency, of perception of the dental communication training courses. This study identified the communication education development to conform with the needs of the clinical field strengthen and cultivate communication competency dental hygienists based on factors of communication education emphasized in focus groups.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.12
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• pp.1-6
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• 2007

In this study, we have performed the channel modification of the conventional MHEMT (metamorphic high electron mobility transistor) to improve the breakdown characteristics. The Modified channel consists of the InxGal-xAs channel and the InP sub channel instead of the InxGa1-xAs channel. Since InP has the lower impact ionization coefficient in comparison with In0.53Ga0.47As, we have adopted the InP-composite channel in the modified MHEMT. We have investigated the breakdown mechanism and the RF characteristics for the conventional and the InP- composite channel MHEMTs. From the measurement results, we have obtained the enhanced on and off-state breakdown voltages of 2.4 and 5.7 V, respectively. Also, the increased RF characteristics have brought about the decreased output conductance for the InP-composite channel MHEMT. The cut-off frequency (fT) and the maximum oscillation frequency (fmax) for the InP-composite Channel MHEMT were 160 GHz and 230 GHz, respectively. It has been shown that the InP-composite channel MHEMT has the potential applications for the millimeter wave power device.