• Title/Summary/Keyword: Jungki

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Wood Thermal Conductivity Database Construction for the Application of Building Energy Simulation (건축물 에너지 시뮬레이션 적용을 위한 목재 열전도율 데이터베이스 구축)

  • Seo, Jungki;Kang, Yujin;Kim, Sumin
    • Journal of the Korea Furniture Society
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    • v.27 no.2
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    • pp.122-127
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    • 2016
  • The increasing interest in the environment and climate change around the globe, while the importance of building energy saving is increasing. The building energy simulation program is used for evaluating of energy performance of buildings. However, an input value of wood thermal conductivity in the programs is different from each other. Therefore, in this study, wood thermal conductivity was measured according to species. Through construction database by species of wood, the error of simulation program are able be decreased. In addition, if used as a structural and interior of buildings, the thermal conductivity and moisture of the wood is difficult to apply to the program because they were changed according to the occupant's lifestyle. In this paper, thermal conductivity and moisture content.of wood confirmed changes in the constant temperature and relative humidity ($25^{\circ}C$, 50% R.H.) condition.

A Analysis Study of Dual-Mode Scramjet Engine Flowpath (이중모드 스크램제트 엔진 Flowpath 해석 연구)

  • Byun, Jong-Ryul;Ahn, Jungki;Ananthkrishnan, N.
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2017.05a
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    • pp.277-284
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    • 2017
  • This study is the results of the analytical research for a dual-model scramjet engine flowpath which is included inlet, isolator, combustor, and nozzle. To design a dual-mode scramjet engine and to investigate its performance, the performance analysis models and tools are required to develope for aerodynamic, thermodynamic characteristics, propulsion, and total system. Therefore, analysis models for air inlet, isolator, supersonic combustor, and nozzle of a dual-mode scramjet engine were accomplished, the performance characteristics of a dual-mode scramjet engine is investigated with using the developed analysis tools.

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An Analytical Study on Structural Stability Evaluation and Design Improvement of Fire Truck Water Tank for Aircraft Rescue (항공기 구조용 소방차 탱크룸의 구조 안정성 평가 및 설계 개선에 대한 해석적 연구)

  • Hyukjin Kwon;Myeongcheol Kang;Suil Lim;Han wook Kim;Jungki Hong;Ho Lee;Yongson Hwang
    • Journal of Drive and Control
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    • v.20 no.1
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    • pp.1-7
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    • 2023
  • In this study, the structural stability of the tank room of an aircraft rescue fire engine is to be studied. The tank room of the aircraft rescue fire engine is filled with fire extinguishing water and chemicals. Fire extinguishing water and chemical are filled to a capacity of about 12.5 tons and are subjected to high stress. The tank room is made of PP material with low yield stress. Structural analysis of the tank room is performed and structural weakness is analyzed. In addition, if a structural problem occurs as a result of structural analysis, an analysis simulation result is presented to derive an improved design and to show the validity of the structural stability of the tank room.

The Effect of Psychological Control Felt by Overseas Medical Tourists on Service Satisfaction and Word of Mouth Communication (해외 의료관광객이 느끼는 통제력이 서비스 만족 및 구전의도에 미치는 영향)

  • Chengcheng Ma;Jungki Lee
    • Asia-Pacific Journal of Business
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    • v.14 no.3
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    • pp.25-44
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    • 2023
  • Receiving medical services abroad is an event that involves a high level of risk and stress for most people. This study proposes and empirically examines perceived control as a factor that has a potential to reduce the stress associated with overseas medical experience and enhance satisfaction with it. Based on the research findings in environmental psychology, one's perceived control was divided into cognitive control, behavior control, and decision control. A research model and a set of hypotheses were constructed to investigate the effect of each control on satisfaction and word-of-mouth communications among consumers who had overseas medical service experiences. The data collection was conducted through an online survey of 220 Chinese consumers who had visited Korea as plastic medicine tourists. Satisfaction with their service experience was significantly affected by both behavioral control and decisional control, but not by cognitive control. Thus, Chinese medical tourists prefer to maintain the belief that they are in charge of major decisions associated with the medical procedure, and that the results of the medical procedure will have personally desirable consequences. In addition, satisfaction experienced by Chinese consumers with overseas medical services had a significant impact on their word-of-mouth activities. Based on the research results, a set of academic and practical implications were derived.

An Investigation of Factors Affecting Consumer Intention to Use Branded App : Focused on Technology Acceptance Model(TAM) (브랜드앱(Branded App)의 사용의도에 영향을 미치는 요인에 관한 연구 : 기술수용 모델(TAM)을 중심으로)

  • Jang, Sunghyun;Lee, Jungki
    • Journal of Information Technology Services
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    • v.13 no.3
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    • pp.51-76
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    • 2014
  • As the smart phone devices gain popularity, companies no longer consider mobile application marketing as an auxiliary marketing tactic. The branded mobile application (branded app) becomes an important part of marketing strategies. This study is an attempt to investigate antecedents of the use intention of the branded app from the perspective of TAM (Technology Acceptance Model). This study takes a macro perspective in explaining the adoption process by incorporating a set of new, yet promising additional variables into the TAM model such as flow experience, benefits, innovation inclination, and customization features. Data were collected by using a survey research. A total of 270 responses were collected. Questionnaires from 25 individuals were removed from the data set due to the insincere responses, leaving the final sample size of 245. Findings support all but one hypotheses of the study. Both perceived utilitarian benefits and customization features of the branded app were found to have positive influences on the perceived usefulness of the branded app. Also, the innovation inclination and perceived entertainment of branded app users showed positive influences on the perceived ease of use of branded app. In addition, it was shown that the perceived usefulness about the use of the branded app influenced positively the flow experience and the users' attitudes toward branded app. Also, the ease of use perceived by branded app users had positive influences on the perceived usefulness and the user's attitude toward branded app. However, the ease of use of branded app did not have a significant influence on the flow experience among users. Moreover, the flow experience from the use of branded app users influenced positively the user's attitude toward branded app. Finally, the users' attitudes toward branded app had positive influences on their intention to use the branded app. Implications for practitioners and academicians are provided.

Study on the Free Volume in Polymer by Positron Annihilation Lifetime Spectroscopy (PALS) (양전자소멸 수명시간 측정을 통한 폴리머소재의 자유부피에 관한 연구)

  • Kim, Yongmin;Shin, Jungki;Kwon, Junhyun
    • Journal of the Korean Society of Radiology
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    • v.6 no.6
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    • pp.489-493
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    • 2012
  • Positron Annihilation Lifetime Spectroscopy is a non-destructive technique to study voids and defects in solids by the measurement of gammas from electron-positron annihilation. In this study, we measured the lifetime of CR, EPDM, NBR, all of which are widely used polymer in various fields. A conventional fast-fast coincidence system in KAERI(Korea Atomic Energy Research Institute) has been used to measure the lifetime spectra, Three lifetime components were analyzed from each lifetime spectra. According to Tao-Eldrup model equation, the size and fraction of free-volume were calculated. Mean radius and free volume fraction of CR, EPDM NBR are $0.1217nm^3$(1.9103%), $0.14780nm^3$(5.3147%), $0.1216nm^3$(2.6381%), respectively. Through these measurements, we identified the feasibility of the PAL system for polymer analysis.

A Substitute Model Learning Method Using Data Augmentation with a Decay Factor and Adversarial Data Generation Using Substitute Model (감쇠 요소가 적용된 데이터 어그멘테이션을 이용한 대체 모델 학습과 적대적 데이터 생성 방법)

  • Min, Jungki;Moon, Jong-sub
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.29 no.6
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    • pp.1383-1392
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    • 2019
  • Adversarial attack, which geneartes adversarial data to make target model misclassify the input data, is able to confuse real life applications of classification models and cause severe damage to the classification system. An Black-box adversarial attack learns a substitute model, which have similar decision boundary to the target model, and then generates adversarial data with the substitute model. Jacobian-based data augmentation is used to synthesize the training data to learn substitutes, but has a drawback that the data synthesized by the augmentation get distorted more and more as the training loop proceeds. We suggest data augmentation with 'decay factor' to alleviate this problem. The result shows that attack success rate of our method is higher(around 8.5%) than the existing method.

A Convergence Research for Development of VR Education Contents for Core Fundamental Nursing Skills (핵심기본간호술 VR 교육 콘텐츠 개발을 위한 융복합 연구)

  • Kim, Jungki;Yu, Hye-Yon;Lee, Young-Soo
    • The Journal of the Korea Contents Association
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    • v.21 no.9
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    • pp.714-722
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    • 2021
  • In this study, intends to propose virtual reality education contents for fundamental nursing skills to develop various teaching methods in nursing education. Blood sugar test & insulin subcutaneous injection among the 20 core fundamental nursing skills is one of that frequently performed and can be used for self-management education for diabetic patients. This study designed a core fundamental nursing skill on immersive VR contents by dividing the learner's experience into three stages: guide, mission, and feedback with these skills. And it is designed by tracking the movement of the hand through finger joint recognition without using a controller for immerse in training. This study will help develop VR nursing education contents that can improve clinical practice competency and the effect of the nursing education.

Development of Appropriate Acid Digestion Method used for the Determination of Total Uranium in Soil by Inductively Coupled Plasma-Mass Spectrometer (ICP-MS) (유도결합플라즈마-질량분석기(ICP-MS)를 이용한 토양의 총 우라늄 정량에 요구되는 적정 산분해 전처리 방법 개발)

  • Shin, Gunhwan;Lee, Goontaek;Kang, Jiyoung;Yoon, Jungki;Kim, Hyunkoo;Noh, Hoejung;Kim, Jiin;Kim, Kyehoon
    • Journal of Soil and Groundwater Environment
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    • v.23 no.6
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    • pp.73-81
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    • 2018
  • Inductively coupled plasma-mass spectrometry (ICP-MS), one of the most commonly used instruments for metal analysis, was used to determine total uranium in soil. The method was named as "Modified ASTM C1345-96". When comparing with ASTM C1345-96, digestion time (2~3 days) was shorten to 7 hours and the treatment in furnace was eliminated. In analyses of 26 field soil samples, there was a significant difference in the average concentration of total uranium between modified ASTM C1345-96 and ASTM C1345-96 (F : 6.22 > Fc : 4.03, significance level : 0.05, n=26). The average concentration of modified ASTM C1345-96 was 1.8 times larger than that of ASTM C1345-96. In addition, modified ASTM C1345-96 was compared with other acid digestion methods for soil including ISO 11466, Modified ISO 11466, US EPA-3051, US EPA-3051A and US EPA-3052 using a certificated reference material (SRM 2711a, NIST) and field soil samples with different level of organic matter content (1.6%, 5.8%, 10.6%). Modified ASTM C1345-96 showed the best accuracy of 93.01% for SRM 2711a. Also, modified ASTM C1345-96 showed the higher extraction rates than other digestion methods by 11~45%.

Effects of supplementation of high pressured red ginseng and ginseng berry on the duration of running time to exhaustion and the body lipid profiles in SD rats (5주간의 초고압 홍삼섭취가 흰쥐의 운동지속시간 및 체내 지질성분에 미치는 영향)

  • Kim, Shinae;Shin, Myungkil;Kim, Jungki;Lee, Myungsook;Park, Hyon
    • Korean Journal of Exercise Nutrition
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    • v.14 no.2
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    • pp.63-68
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    • 2010
  • This study evaluated the effects of high pressured red ginseng(HRG) and ginseng berry(GB) supplementation on lipid profiles and run to exercise time in SD rats. Five weeks-old male rats were randomly assigned into six groups, ie. control group(AC: n = 8), exercise group(AE: n = 7), general extracted red ginseng group(C: n = 8), HRG group(high density D: n = 8, low density E: n = 7), and HRG + GB group(F: n = 7). The AC and AE groups had a supplementation of AIN-93G, and AE group performed 40 min treadmill exercise five times per week for five weeks. E, C, D, and F groups had a supplementation composed of general extracted red ginseng(GRG), HRG(250 mpk and 500 mpk), and HRG(250 mpk) + GB(167 mpk) in the AIN-93G. Main results of the study were as follow 1) the duration of running time to exhaustion was higher in exercise group compared to other groups. HRG had no effect on run to exhaustion time, but, GRG and HRG + GB showed longer run time than control groups. 2) Blood TC, TG, HDL-C and liver TG showed no difference between groups, but, liver TC showed lower level in the HRG groups than other groups. It was concluded that the 5 weeks of supplementation of HRG extract would have positive effects on liver cholesterol, and GRG and HRG + GB have a positive effect on exercise performance tested run to exhaustion time, but, we can not find a positive effect of supplementation of HRG on exercise performance.