• Korean Journal of Materials Research
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• v.9 no.11
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• pp.1095-1101
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• 1999

Electroless Ni plating is applied to form bumps and UBM layer for flip chip interconnection. Characteristics of electroless Ni are also investigated. Zincate pretreatment is analyzed and plated layer characteristics are investigated according to variables like temperature, pH and heat treatment. Based on these observations, characteristics dependence to each variables and optimum electroless Ni plating conditions for flip-chip interconnection are suggested. Electroless Ni has 10wt% P, $60\mu\Omega$-cm resistivity, 500HV hardness and amorphous structure. It changes crystallized structure and hardness increases after heat treatment After interconnection of electroless Ni bumps by ACF flip chip method, we show their advantages and possibility in microelectronic package applications.

• Journal of the Society of Naval Architects of Korea
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• v.57 no.4
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• pp.182-190
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• 2020

This study reports a series of drop impact tests performed to generate denting damages on stiffened plates and their residual ultimate strength tests under axial compression. The models were fabricated of general structural steel, and each model has six longitudinal stiffeners and two transverse frames. Among six fabricated models, four were damaged, and two were left intact for reference. To investigate the effects of collision velocity and impact location on the extent of damage, the drop height and the impact location were changed in each impact test. After performing the collision tests, the ultimate axial compression tests were conducted to investigate the residual strengths of the damaged stiffened plates. Finite element analyses were also carried out using a commercial package Abaqus/Explicit. The material properties obtained from a quasi-static tensile tests were used, and the strain-rate sensitivity was considered. After importing the collision simulation results, the ultimate strength calculations were carried out and their results were compared with the test data for the validation of the finite element analysis method.

• The Korean Journal of Food And Nutrition
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• v.28 no.4
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• pp.717-727
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• 2015

Although the NutriPlus program has shown considerable evidence of enhancing users' nutritional status, the budget does not cover all eligible mothers and children. This study aimed to conduct a cost-benefit analysis of the NutriPlus program to assess its economic efficiency. 53 families with 79 users in the NutriPlus program at Daejeon Dong-gu Health Center participated in this study with informed consent. The costs and benefits were estimated from both the administrator's and users' perspectives. We converted the time cost into Korean currency based on the minimum wage in 2014. The value of nutrition education and service (B2), estimated by contingency valuation method (CVM), was counted as an economic benefit. 6 families (11.3%) were recipients of national medical care and 22 families (41.5%) paid 10% of the food package cost by themselves. The total cost was \7,450,167 and the total benefit was \12,402,239. The budget for the health center (C1+C2+C3+C4) was \5,984,381 a month. Time and transportation cost for receiving nutrition education (C6) differed significantly according to the economic status of families. Household food consumption increase (C4-B4) was 40,379 in the poverty group, which was four times more than in the other groups. The net benefit (B-C) was \4,852,172 and the B/C ratio was 1.66. Therefore, the NutriPlus program is beneficial in the economic aspect as well as in the nutritional aspect. If the enhancement of nutritional status was also considered, the total benefit would be even higher. These results confirm the legitimacy of a secure budget for the NutriPlus program. And we suggest expanding its budget to cover more eligible individuals to improve people's health and welfare.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.3
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• pp.137-143
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• 2009

Through the development of techniques, robots are becomes smaller, and many of robots needed for application are greater and greater. Method of coordinating large number of autonomous robots through local interactions has becoming an important research issue in robot community. Swarm Robot System is a system that independent autonomous robots in the restricted environment infer their status from preassigned conditions and operate their jobs through the coorperation with each other. Within the SRS,a robot contains sensor part to percept the situation around them, communication part to exchange information, and actuator part to do a work. Specially, in order to cooperate with other robots, communicating with other robot is one of the essential elements. In such as Bluetooth has many adventages such as low power consumption, small size module package, and various standard procotols, it is rated as one of the efficent communcating system for autonomous robot is developed in this paper. and How to construct and what kind of procedure to develop the communicatry system for group behavior of the SRS under intelligent space is discussed in this paper.

• Journal of Korean Dental Science
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• v.3 no.2
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• pp.20-25
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• 2010

Aim : This study was conducted to assess the oral health status of deaf and mute children attending special school. Materials and Methods : A cross-sectional descriptive survey was conducted among 137 deaf and mute children with ages ranging from 7 to 18 years. A total of 76 males (55.47%) with mean age of $14.2{\pm}4.5$ and 61 females (44.53%) with mean age of $13.8{\pm}4.2$ years and studying in a school for deaf and mute children in Warora were considered. Data were collected using a standard method recommended by WHO for the oral health survey in 1977. Oral health status was assessed using OHIS, Loe and Sinless, and CPI Index along with DMFT and DMFS Index. Gingival position was considered for measuring attachment loss. Statistical analysis was performed using the SPSS software package (version 17.0). Results : The mean DMFT was found to be $2.53{\pm}1.72$, and mean DMFS, $3.37{\pm}3.16$. The prevalence of dental caries was pegged at 35.32%, with mean OHIS score at $1.49{\pm}0.76$. Overall gingival index among deaf and mute children was $0.81{\pm}1.4$, whereas that for the upper arch and lower arch was $0.92{\pm}0.84$ and $1.19{\pm}0.95$, respectively. The mean score for the CPI Index among deaf and mute children was found to be $0.42{\pm}0.32$. Gingival clinical attachment loss was found to be $0.26{\pm}0.15mm$. Conclusion : These findings suggest that children with hearing disabilities can also have good oral hygiene comparable to normal individuals of the same age group. These results may be attributed to the fact that the study sample was taken from a single school of a private organization with a well-equipped dental setup.

• The Research Journal of the Costume Culture
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• v.23 no.1
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• pp.32-44
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• 2015

Increasing of Korean old women's rate is demographic characteristics attributed an aging society, silver generation would lead to silver fashion market with steady competitiveness and interest in fashion. So the study attempts to use foundation material for silver's fashion design by analyzing design characteristics and processing development of design representative women's top. Selecting brand for collecting photo using study represents a mid- and premium-priced with reference Brand Yearbook. After selecting brand on domestic and foreign I have collected picture from Internet shopping mall and web-site of fashion brand, from October 2013 to July 2014, but I selected 840 pictures based on front poses for easy decision. In order to search design characteristics according to sort of silver blouse design on domestic and foreign. I have examined shape, color, pattern, fabric sensation, inside composition line and decoration with reference standard of analysis in preceding research. Data analysis method was conducted on analysis of frequency and cross analysis using SPSS statistical package 21.0. The conclusion of design characteristic according to type of blouse design for silver, H-silhouette in shirt blouse seems to fit in body transformation and expose silhouette with correcting the body flaw. Using soft material in T-shirt blouse they are able to conceal a body defect and express beautiful silhouette. By using detail in pullover shirt blouse and tunic blouse for point of design, it express glamour and luxurious. Most of blouse are printed various pattern, it would looks more gorgeous using pattern.

• Korean Journal of Community Nutrition
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• v.8 no.6
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• pp.977-985
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• 2003

This study was done to evaluate the health and nutritional status of female college students in Seoul. The subjects were 63 healthy college students aged 20 to 29 years. Their body composition, dietary intakes, clinical blood indices were investigated. Their body composition was determined by means of a multifreqency bioelectrical impedance analysis. Their dietary intake was determined using 3-day record method and their nutrient intake was analyzed by Computer Aided Nutritional analysis program for professional (CAN-pro). Their hemoglobin, hematocrit, red blood cell (RBC), white blood cell (WBC) and mean corpuscular volume (MCV) were determined by semi-automated microcell counter (F-520). Their plasma total cholesterol, TG, and HDL-cholesterol levels were measured using test kits. All data were statistically analyzed by SAS PC package program. Their average consumption of calcium, iron vitamin A, vitamin B2 and niacin were 63.3%, 65.0%, 85.2%, 89.2% and 95.2% of RDA, respectively. The overall mean values of the hematological indices in the female college students were within the normal range. However anemic subjects with hemoglobin (< 12 g/dl) and hematocrit (<36%) accounted for about 20% of the subjects. The mean levels of total cholesterol, HDL-cholesterol and TG were 188.4mg/dl, 69.9mg/dl and 67.4mg/dl, respectively. The percentages of the subjects with plasma total cholesterol level (> 200mg/dl) and LDL-cholesterol (＞130mg/dl) were about 41% and 30.4%, respectively. The data showed a significantly positive correlation between either body fat (%) or BMI and TG. However. there was a significantly negative correlation between either body fat (%) or BMI and HDL-cholesterol. These overall results suggest that it is necessary for college women to be educated regarding consuming more iron and vitamin C and less fat, in order to prevent iron deficiency anemia and/or cardiovascular diseases in later life.

• The KSFM Journal of Fluid Machinery
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• v.19 no.4
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• pp.35-38
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• 2016

A PFA lined ball valve, which is machined with fluorinated resin PFA to its inner part for improving corrosion resistance, non-stickness, heat-resistance, has been widely used in semiconductor/LCD manufacturing processes with the high purity chemicals as working fluid. Due to the safety concerns, the experiments for measuring the flow coefficient of a PFA lined ball valve should be conducted with water at room temperature according to IEC standards. However, it is required to know the real flow coefficient with the real working fluid, because the flow coefficient is critical to correctly design valves in piping system. In this study, we calculated the flow coefficient of a PFA lined ball valve 40A with hydrochloric acid ($40^{\circ}C$ 36% HCl) as the working fluid using a commercial CFD package, ANSYS CFX v15. The computational results had a good agreement with the measured data and showed a little difference between water and hydrochloric acid as the working fluid of a PFA lined ball valve.

• Journal of electromagnetic engineering and science
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• v.17 no.1
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• pp.20-28
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• 2017

A fully integrated dual-band CMOS power amplifier (PA) is developed for 802.11n WLAN applications using wafer-level package (WLP) technology. This paper presents a detailed design for the optimal impedance of dual-band PA (2 GHz/5 GHz PA) output transformers with low loss, which is provided by using 2:2 and 2:1 output transformers for the 2 GHz PA and the 5 GHz PA, respectively. In addition, several design issues in the dual-band PA design using WLP technology are addressed, and a design method is proposed. All considerations for the design of dual-band WLP PA are fully reflected in the design procedure. The 2 GHz WLP CMOS PA produces a saturated power of 26.3 dBm with a peak power-added efficiency (PAE) of 32.9%. The 5 GHz WLP CMOS PA produces a saturated power of 24.7 dBm with a PAE of 22.2%. The PA is tested using an 802.11n signal, which satisfies the stringent error vector magnitude (EVM) and mask requirements. It achieved an EVM of -28 dB at an output power of 19.5 dBm with a PAE of 13.1% at 2.45 GHz and an EVM of -28 dB at an output power of 18.1 dBm with a PAE of 8.9% at 5.8 GHz.

• Journal of Korean Academy of Nursing Administration
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• v.11 no.3
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• pp.289-301
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• 2005

Purpose: This study was to examine the ego-identity of nursing students and their adjustment to home and university in an effort to identify the correlation of their ego-identity to their adjustability and lay the foundation for providing better personality education to them. Method: The subjects in this study were 400 nursing students at H and S universities in south Chungcheong province. The instruments used in this study were Park A-cheong(2003)'s Korean-version Ego-Identity Inventory and Jeong Jonggweon(1998)'s Home and School Adjustment Inventory. For data analysis, SPSS/PC+ Package was used, and statistical data on frequency and percentage were obtained. Besides, t-test, one-way ANOVA and Pearson correlation coefficient were employed. Result: The findings of the study were as follows: The nursing students investigated got a 3.46 and 3.53 in ego-identity and family life adjustment respectively out of possible five points, which were both above the average. Their score in school adjustment was 2.89, which wasn't high. As for connections between general characteristics and ego-identity, their academic school year, their type of residence, presence or absence of parents and their birth order made no statistically significant differences to their ego-identity. But as to motivation of choosing nursing, the students who chose their major at their own option were the best in that regard. Their adjustment to family life made no significant differences, and regarding school adjustment, ego-identity was better among those who lived in a lodging house or dormitory(F=4.01, p<.05) and who chose their major at their own option(F=4.88, p<.01). In addition, those with better ego-identity were better adjusted to home and school. Conclusion: As the above-mentioned findings suggested that nursing educators should teach students by mapping out specific plans to enhance the ego-identity of students and facilitate their school adjustment, and full-fledged nurses should be produced by teaching students to build the right work ethics and become qualified as a professional.