• Title/Summary/Keyword: Gi-Hak

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Compressive Strength Control of High Strength Concrete Structure Using Samples with Isolated Junction Test (고강도콘크리트 벽체부재에 접합분리 시험체를 활용한 강도관리에 관한 연구)

  • Ki, Jun-Do;Kim, Hak-Young;Kim, Kwang-Ki;Paik, Min Su;Lim, Nam Gi;Jung, Sang Jin
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2009.11a
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    • pp.47-50
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    • 2009
  • The existing techniques used to estimate and manage the compressive strength of concrete do not include the environmental factors that influence the development of compressive strength and the compressive strength itself. Thus, it is necessary to develop a reasonable yet simple way to measure the compressive strength of concrete structures at construction sites by considering concrete's mechanical properties and curing environment. This study was conducted to propose an acrylic form and a junction isolation mold with crack-inducing boards that uses non-destructive methods to create and collect concrete test samples that are cured in the same condition as the actual concrete structures. junction isolation molds were used in high-strength and super high-strength concrete to evaluate the reliability of compressive strength evaluation on the test sample. The following were the findings of this study:

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A research for self-supporting management of business incubation center in region (지역 내 창업보육센터의 발전 방향에 대한 소고(小考))

  • Moon, Hyung-Joo;Choi, Kyo-Won;Hong, Ki-Hak;Lee, Gi-Sung;Son, Chang-Kyun
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.2 no.1
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    • pp.1-14
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    • 2007
  • In this paper we investigated the organization of regional business incubation center itself and that of companies in center and scrutinized the problems and obstacles to take self-supporting administration for both of center and companies in it. We classified the companies operating inside the center into four types according to the formation of organizations analyzed them, and proposed some solutions to enhance their operating abilities to obtain elf- supporting administration.

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Physiological Assessment of the Psychophysical Maximum Acceptable Weight of Load for Manual Materials Handling Tasks (인력물자취급시의 인체심리학적 최대허용중량의 생리학적 고찰)

  • Jeong, Seong-Hak;Kim, Hong-Gi
    • Journal of the Ergonomics Society of Korea
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    • v.18 no.1
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    • pp.1-12
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    • 1999
  • The objective of this study was to investigate the metabolic energy consumption rate of the psychophysical Maximum Acceptable Weight of Loads (MAWLs) for different manual materials handling tasks. Lifting activities with four different lifting frequencies (2, 5, 8, 11 lifts/min) for a lifting range (from floor to 76cm height) were studied. The oxygen consumption rate and heart rate were measured or recorded while subjects were lifting their MAWLs. It was found that the relationship between MAWL and frequency can be described best by the exponential function with the R-sq value 0.9865 for this study. Psychophysical MAWL decreased from 22.38 to 7.48 kg, while the oxygen consumption rate with the MAWL increased from 717.8 to $1114.7m{\ell}-O_2/min$ as the frequency increased from 2 to 11 lifts/min. Heart rate also increased from 104.5 to 120.7 bpm. The ratio of oxygen consumption for the MAWL to the Physical Work Capacity (PWC) ranged from 28 to 43%. The MAWLs were greater than or equal to the Maximum Permissible Limits (MPLs) when the frequencies were higher than 8 lifts/min. It seems that the MAWLs by psychophysical approach when the frequencies were higher than 8 lifts/min tend to be overestimated from the viewpoint of the physiological criterion of the oxygen consumption rates. From these findings it is suggested that the NIOSH Guideline should not be directly applied to Korean without reasonable modifications.

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2-DOF PID Control for the Steam Temperature Control of Thermal Power Plant

  • Kim, Dong-Hwa;Hong, Won-Pyo;Jung, Chang-Gi;Lee, Seung-Hak
    • Proceedings of the KIEE Conference
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    • 2001.07d
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    • pp.2123-2125
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    • 2001
  • In thermal power plant, the efficiency of a combined power plant with a gas turbine increases, exceeding 50%, while the efficiency of traditional steam turbine plants is approximately 35% to 40%. Up to the present time, the PID controller has been used to operate this system. However, it is very difficult to achieve an optimal PID gain without any experience, since the gain of the PID controller has to be manually tuned by trial and error procedures. This paper focuses on the neural network tuning of the 2-DOF PID controller with a separated 2-DOF parameter (NN-Tuning 2-DOF PID controller), for optimal control of the Gun-san gas turbine generating plant in Seoul. Korea. In order to attain optimal control, transfer function and operating data from start-up, running, and stop procedures of the Gun-san gas turbine have been acquired, and a designed controller has been applied to this system. The results of the NN-Tuning 2-DOF PID are compared with the PID controller and the conventional 2-DOF PID controller tuned by the Ziegler-Nichols method through experimentation. The experimental results of the NN-Tuning 2-DOF PID controller represent a more satisfactory response than those of the previously-mentioned two controller.

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Study on the Comparison of Effects by Extraction Methods of Roast and Raw Semen Zizyphi Spinosae (생산조인(生酸棗仁)과 초산조인(炒酸棗仁)의 추출방법에 따른 효능비교연구)

  • Lee, Eun-Kyoung;Hong, Hak-Gi;Chong, Myong-Soo
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.23 no.6
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    • pp.1416-1422
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    • 2009
  • To observe the difference and change of the efficacy and ingredient appearing according to whether semen zizyphi spinosae has been roasted and its extraction method, locomotor activity, anticonvulsant activity, sleeping effect of each hot water and UMPM low temperature extracts of roast and raw semen zizyphi spinosae were measured through animal tests. Roast semen zizyphi spinosae showed superior pharmacological efficacy than raw semen zizyphi spinosae. Also, hot water extraction method showed superior pharmacological efficacy than low temperature extraction method(UMPM) that uses ultrasonic waves and microwaves. In short, it was shown that herbal medicine's extraction method needs to maximize medicinal effects by trying optimum extraction methods according to efficacy by considering characteristics of each herbal medicine. Together, there's also the need for in-depth studies on water-soluble ingredients of semen zizyphi spinosae that may be extracted through full hot water extraction method.

3GPP RAN LTE 기술 개요 및 표준화 현황

  • Kim, Hak-Seong;Kim, Bong-Hoe;Kim, Gi-Yeong;Choe, Jin-Seong
    • Information and Communications Magazine
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    • v.24 no.3
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    • pp.97-111
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    • 2007
  • 전 세계적으로 2세대 및 3세대 무선이동통신 서비스의 성공적인 상용화에 힘입어 현재 3.5세대 이동통신시스템의 상용화 단계까지 이르렀다. 한걸음 더 나아가 3GPP/3GPP2에서는 MT-2000 고도화시스템에 대한 표준화 작업이 활발히 진행되고 있다. 각 표준화 기구에서 제시한 향후 표준화 일정 및 현재의 기술개발 추세로 미루어 볼 때 수년 내에 무선통신시스템의 새로운 장이 펼쳐질 것으로 기대된다. 특히 3GPP에서는 기존 3G-WCDMA 무선접속기술 대신에 하향 OFDMA 및 상향 SC-FDMA 무선접속기술을 이용하는 E-UTRA/UTRAN 시스템의 표준화 작업을 진행하고 있다. 특히 이 표준화 작업에 전 세계 운영회사, 제조사, 표준화 기구 및 관련종사자들의 관심이 어느 때보다 높기 때문에 표준 기술의 논의 및 검증이 더 활발히 진행되고 있으며 이는 표준기술 완성도를 높여 향후 발간될 LTE 시스템의 경쟁력 제고에 크게 이바지 할 것으로 예상된다. 현재 LTE 표준화 작업은 3단계로 나누어 진행되어 왔으며 2006년 3월 현재 마지막 세 번째 단계를 막 시작하는 시기에 있다. 이에 즈음하여 본기고문에서는 LTE 표준기술의 이해를 돕고 및 향후 표준화에 대한 향방을 가늠하는데 일부 도움을 제공하기 위해 현재까지 진행된 물리계층 표준기술 및 향후 해결해야할 문제들에 대해서 개념위주로 기술하였다. 기고문은 LTE 시스템 요구사항 및 향후 일정을 서론부에 제시하고 이어 E-UTRAN 프로토콜 구조, 상 하향 무선접속 기술, 물리계층 기술표준 현황, 그리고 마지막으로 맺음말의 순으로 구성되어 있다.

Parameter dependent conduction path for nano structure double gate MOSFET (나노구조 이중게이트 MOSFET에서 전도중심의 파라미터 의존성)

  • Jeong Hak-Gi;Lee Jae-Hyeong;Lee Jong-In
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2006.05a
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    • pp.861-864
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    • 2006
  • In this paper conduction phenomena have been considered for nano structure double gate MOSFET, using the analytical model. The Possion equation is used to obtain the analytical model. The conduction mechanisms to have an influence on current conduction are thermionic emission and tunneling current, and subthreshold swings of this paper is compared with those of two dimensional simulation to verify this model. The deviation of current path and the influence of current path on subthreshold swing have been considered according to the dimensional parameters of double gate MOSFET, i.e. gate length, gateoxide thickness, channel thickness. The optimum channel doping concentration is determined as the deviation of conduction path is considered according to channel doping concentration.

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Analysis of Salmonella Contaminated Beef Odor Using an Electronic Nose

  • Kim, Gi-Young;Lee, Kang-Jin;Son, Jae-Yong;Kim, Hak-Jin
    • Food Science of Animal Resources
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    • v.30 no.2
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    • pp.185-189
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    • 2010
  • An electronic nose was used to identify Salmonella contamination on beef based on odors. To detect pathogen contamination of beef, $100{\mu}L$ of $10^5CFU/g$ Salmonella Enteritidis or Salmonella Typhimurium cell suspensions were spiked onto 5 g beef sirloin samples in individual vials. Odor changes over time were then measured and analyzed using an electronic nose system to identify pathogen contamination. In principle, the electronic nose system based on a surface acoustic wave (SAW) detector produced different frequency responses depending on the time and amount of each chemical. Multivariate analysis of the odor data was conducted to detect Salmonella contamination of beef. Salmonella odors were successfully distinguished from uncontaminated beef odors by principal component analysis (PCA). The PCA results showed that Salmonella contamination of beef could be detected after 4 h of incubation. The numbers of cells enumerated by standard plate count after 4 h of inoculation were $2{\times}10^6CFU/g$ for both Salmonella Enteritidis and Salmonella Typhimurium.

3D Avatar Modeling through Composite Photograph for Smartphone Environment (스마트폰 사진 합성을 통한 3D 아바타 모델링)

  • Han, Je-Wan;Lee, Chang-Gyu;Song, In-Seok;Nam, Jae-Woo;Kwon, Gi-Hak;Moon, Hyeonjoon
    • Proceedings of the Korea Information Processing Society Conference
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    • 2018.05a
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    • pp.476-478
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    • 2018
  • 현대 사회의 발전으로 인해 사람들의 삶의 질이 향상됨에 따라 사람들은 다양한 방식으로 자신 및 자신의 개성을 표출하려는 시도를 한다. 특히 IT 기술의 발전은 가상현실 및 3D 기술의 성장을 이끌어냈다. 본 논문은 다가올 4차 산업혁명에 발맞추어 사용자의 개성을 표출할 실용적이고 개성 있는 3D 모델링 아이디어를 제안하고자 한다. 스마트폰 사진 촬영과 동시에 사용자가 선택한 다른 캐릭터 사진과의 합성 사진을 Convolutional Neural Network (CNN)과 Generative Adversarial Network (GAN) 기반 딥러닝 기술을 통해 생성한다. 생성된 이미지는 사용자의 모습과 합성의 대상이 되는 캐릭터의 모습을 동시에 담고 있다. 본 연구의 결과물로 생성된 합성 사진을 3D 프린터를 이용하여 자신만의 모습이 담긴 굿즈를 생산 혹은 이모티콘을 생성하는 등 다양한 실용적인 응용분야에 적용 가능하다.

A Study on Combustion Characteristic with Port-Diameter of fuel in Hybrid Rocket (하이브리드 로켓에서의 연료포트 직경에 따른 연소특성에 관한 연구)

  • Lee, Jung-Pyo;Cho, Jung-Tae;Kim, Gi-Hun;Kim, Soo-Jong;Kim, Hak-Chul;Woo, Kyoung-Jin;Moon, Hee-Jang;Sung, Hong-Gye;Kim, Jin-Kon
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2008.11a
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    • pp.239-242
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    • 2008
  • Combustion Characteristic with initial port-diameter of fuel was studied in hybrid propulsion system using cylindrical single port-grain. In order to understand a variation of combustion characteristic with initial port-diameter, experimental studies were performed with the GOX and $GN_2O$ as oxidizer, and PE as fuel. As results, burning rate decreased with increase of initial port-diameter of fuel. And the variation of burning rate with using $GN_2O$ is smaller than using GOX.

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