• Title/Summary/Keyword: Repeat time

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Effect of Eucommia ulmoides Extracts on Allergic Contact Dermatitis and Oxidative Damage Induced by Repeat Elicitation of DNCB (두충 추출물이 DNCB로 유발된 알레르기성 접촉피부염과 산화적 손상에 미치는 영향)

  • Shon, Mi-Yae;Nam, Sang-Hae
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.12
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    • pp.1517-1522
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    • 2007
  • Inhibitory effects of allergic contact dermatitis of hot water extract of Duchung (Eucommia ulmoides Oliver) leaf, bark and stem growing at Sancheong-gun were investigated for female BALB/c mouse induced by repeat elicitation of DNCB (2,4-dinitro-chlorobenzene). Skin reactions, consisting of increased ear thickness and the presence of ear inflammation, were observed in mice treated with DNCB and Duchung. Weight of lymph node, spleen and thymus in mice treated with Duchung extracts were lower than that of mouse treated with DNCB. Ear weight of mouse treated with Duchung extracts was decreased by increasing the concentration of sample as compared to control group and dropped as low as control level at 1,000 mg/kg. Ear thickness became thinner as test time on Duchung extract progressed. MDA (malondialdehyde) contents in liver tissue were not different in sample group with DNCB group, but were different in ear tissue. NO (nitric oxide) contents was decreased in Duchung extract groups at serum and ear tissues as compared to 1% DNCB group. In the present study, the results suggested that Duchung extract inhibits inflammatory response and oxidative damage induced DNCB allergen.

Effect of Types of Force-fields on Gas Transport Thorough Polymer Membrane (Force-field가 고분자 분리막의 기체 투과거동에 미치는 영향)

  • Lee, Ji-Su;Park, Chi Hoon
    • Membrane Journal
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    • v.29 no.1
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    • pp.37-43
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    • 2019
  • In this study, we investigated how the force-field, which is the most important factor to define atomic motion in molecular dynamics (MD), affects the motion of the polymer and gas molecules. The repeat units and the polymer structure were well simulated in all five force-fields, and the distribution of the polymer linear chain in the final polymer 3D model did not show any significant difference. However, the movement of actual gas molecules showed a very different tendency, which was also observed in COMPASS and pcff using the same functional form. Therefore, even if the same structure is used, it can be seen that the motion of the gas molecule moves under the influence of the force-field continuously over time, so that the effect is much larger than that of macromolecules such as a polymer linear chain. Accordingly, in case of using different force-fields, it is necessary to be very careful in comparison of those results.

A Study on Improvement of Submarine Torpedo Acoustic Counter Measure Launcher System Safety Device Performance (잠수함용 어뢰기만기 발사체계 안전장치 작동성능 향상에 관한 연구)

  • Chang, Ho-Seong;Seo, Dae-Su;Lee, Gyeong-Chan;Lee, Jong-Gwan;Jo, Byeong-Gi;Kim, Joong-Bae
    • Journal of Korean Society for Quality Management
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    • v.46 no.3
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    • pp.411-424
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    • 2018
  • Purpose: The purpose of this study is to improve submarine TACM launcher system safety device performance. Methods: In this study, EPLD(Electrically Programmable Logic Device) control and time sharing method to the safety device actuator motor and discrete signal processor in launch control panel were used to resolve unusual performance of safety system. Results: The result of this study are as follows; First, sporadic stopping of safety device actuator motor due to insufficient In-Rush current was resolved. Second, repeat of safety device condition as lock & release due to chattering for motor activating was resolved. Third, simultaneous release function for safety device actuator was available. Conclusion: The unusual performance of function for submarine TACM launcher system was overcame by applying EPLD control and time sharing method. The suggestions were proved by performance test in the pressure chamber. The results of this study enhanced survivability of ${\bigcirc}{\bigcirc}{\bigcirc}$ class submarine from enemy torpedo.

A Case Study on Manufacturing Processes for Virtual Garment Sample

  • Choi, Young Lim
    • Fashion & Textile Research Journal
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    • v.19 no.5
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    • pp.595-601
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    • 2017
  • Advances in 3D garment simulation technology contribute greatly to consumers becoming more immersed in movies and games by realistically expressing the garments the characters in the movie or game are wearing. The fashion industry has reached a point where it needs to maximize efficiency in production and distribution to go beyond time and space in order to compete on the global market. The processes of design and product development in the fashion industry require countless hours of work and consume vast resources in terms of materials and energy to repeat sample production and assessment. Therefore, the design and product development tools and techniques must aim to reduce the sample making process. Therefore, this study aims to study a case for comparing the real garment sample making process to the virtual garment sample making process. In this study, we have analysed the differences between the real and virtual garment making processes by choosing designated patterns. As we can see from the study results, the real and virtual garments generally are made through similar processes in manufacturing, while the time consumed for each shows great variation. In real garment making, scissoring and sewing require the greatest number of work hours, whereas in virtual garment making, most of the time was spent in the simulation process.

Performance of ARQ-Aided Downlink Time Switched Transmit Diversity in the WCDMA LCR-TDD System (WCDMA LCR-TDD 시스템에서 ARQ가 적용된 하향링크 TSTD의 성능)

  • Jeon, Cha-Eul;Ma, Ri-A;Hwang, Seung-Hoon
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.46 no.5
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    • pp.104-108
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    • 2009
  • In this paper, we investigate the performance of ARQ-aided downlink Time Switched Transmit Diversity (TSTD) in the WCDMA LCR-TDD system. Proposed TSTD system applies the ARQ scheme in which the receiver sends the response signal (ACK or NACK signal) to the transmitter and predicts the channel condition based on response signal after receiver checks the error, then it re-sends data. Simulation results demonstrate that the proposed TSTD scheme yields about 5.5dB performance gain, compared with the conventional TSTD in term of the frame error rate(FER) for a mobile speed of 3km/h and an FER value of 1%. In addition, 7% of throughput gain is shown when Eb/N0=7dB.

Improvement and Performance Analysis of Hybrid Anti-Collision Algorithm for Object Identification of Multi-Tags in RFID Systems (RFID 시스템에서 다중 태그 인식을 위한 하이브리드 충돌방지 알고리즘의 개선 및 성능 분석)

  • Choi, Tae-Jeong;Seo, Jae-Joon;Baek, Jang-Hyun
    • IE interfaces
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    • v.22 no.3
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    • pp.278-286
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    • 2009
  • The anti-collision algorithms to identify a number of tags in real-time in RFID systems are divided into the anti-collision algorithms based on the Framed slotted ALOHA that randomly select multiple slots to identify the tags, and the anti-collision algorithms based on the Tree-based algorithm that repeat the questions and answer process to identify the tags. In the hybrid algorithm which is combined the advantages of these algorithms, tags are distributed over the frames by selecting one frame among them and then identified by using the Query tree frame by frame. In this hybrid algorithm, however, the time of identifying all tags may increase if many tags are concentrated in a few frames. In this study, to improve the performance of the hybrid algorithm, we suggest an improved algorithm that the tags select a specific group of frames based on the earlier bits of the tag ID so that the tags are distribute equally over the frames. By using the simulation and mathematical analysis, we show that the suggested algorithm outperforms traditional hybrid algorithm from the viewpoint of the number of queries per frame and the time of identifying all tags.

Effectiveness and Retention of Repeated Simulation-based Basic Life Support Training for Nursing Students (간호학생 대상 시뮬레이션기반 기본소생술 반복교육의 효과와 지속성)

  • Jung, Ji Soo;Hur, Hea Kung
    • Journal of Korean Critical Care Nursing
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    • v.6 no.2
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    • pp.24-36
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    • 2013
  • Propose: This study was to investigate the educational effect and retention of repeated simulation-based basic life support (BLS) training for nursing students. Methods: A comparison group design with pretest and posttest was used. A total of 35 nursing students (18 for the experimental group, 17 for the control group) participated in the study. A repeated simulationbased BLS training program which include a lecture, skills training, and two repeated sessions of simulation practice and debriefing was provided twice for experimental group. Knowledge, self-efficacy, and skill performance of cardiopulmonary resuscitation (CPR) were measured three times: at baseline, week 2, and week 6. Descriptive analysis, repeated measures ANOVA, and t-test were used for data analyses. Results: Knowledge, self-efficacy and skill performance of CPR were not significantly changed by group assignment, by the time, and interaction of group by time. Effectiveness of intervention was not maintained until Week 6. Conclusion: The results suggest that the timing of repeat education, total training time, and students' mastery of CPR performance should be considered when developing simulation-based programs to improve and maintain students' CPR knowledge, self-efficacy, and skill performance.

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Design of a Nuclear Reactor Controller Using a Model Predictive Control Method

  • Na, Man-Gyun;Jung, Dong-Won;Shin, Sun-Ho;Lee, Sun-Mi;Lee, Yoon-Joon;Jang, Jin-Wook;Lee, Ki-Bog
    • Journal of Mechanical Science and Technology
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    • v.18 no.12
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    • pp.2080-2094
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    • 2004
  • A model predictive controller is designed to control thermal power in a nuclear reactor. The basic concept of the model predictive control is to solve an optimization problem for finite future time steps at current time, to implement only the first optimal control input among the solved control inputs, and to repeat the procedure at each subsequent instant. A controller design model used for designing the model predictive controller is estimated every time step by applying a recursive parameter estimation algorithm. A 3-dimensional nuclear reactor analysis code, MASTER that was developed by Korea Atomic Energy Research Institute (KAERI), was used to verify the proposed controller for a nuclear reactor. It was known that the nuclear power controlled by the proposed controller well tracks the desired power level and the desired axial power distribution.

Design of MSSTC for MIMO Retransmissions (다중 안테나 재전송 환경을 위한 MSSTC 부호화 기법)

  • Ko, Dong-Ju;Lee, Jeong-Woo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.5C
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    • pp.265-275
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    • 2011
  • In this paper, we propose a Multi-Strata Space Time Code(MSSTC) for MIMO retransmissions. Since MSSTC is constructed by superimposing two OSTBC matrices, there are no intra-stratum interferences, but there exist inter-strata interferences. In MIMO retransmission environment, the transmitter switches adaptively the phases of strata at each transmission by using 1-bit feedback sent from the receiver in order to reduce the inter-strata interferences efficiently. We also propose a power allocation scheme between strata to improve error performance. Simulation results show that the proposed scheme achieves better performance than other conventional schemes.

A Fast Volume Rendering Algorithm for Virtual Endoscopy

  • Ra Jong Beom;Kim Sang Hun;Kwon Sung Min
    • Journal of Biomedical Engineering Research
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    • v.26 no.1
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    • pp.23-30
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    • 2005
  • 3D virtual endoscopy has been used as an alternative non-invasive procedure for visualization of hollow organs. However, due to computational complexity, this is a time-consuming procedure. In this paper, we propose a fast volume rendering algorithm based on perspective ray casting for virtual endoscopy. As a pre-processing step, the algorithm divides a volume into hierarchical blocks and classifies them into opaque or transparent blocks. Then, in the first step, we perform ray casting only for sub-sampled pixels on the image plane, and determine their pixel values and depth information. In the next step, by reducing the sub-sampling factor by half, we repeat ray casting for newly added pixels, and their pixel values and depth information are determined. Here, the previously obtained depth information is utilized to reduce the processing time. This step is recursively performed until a full-size rendering image is acquired. Experiments conducted on a PC show that the proposed algorithm can reduce the rendering time by 70- 80% for bronchus and colon endoscopy, compared with the brute-force ray casting scheme. Using the proposed algorithm, interactive volume rendering becomes more realizable in a PC environment without any specific hardware.