SIP 말뚝의 비선형 수치모델식 산정

황의성(Hwang Yi-Sung),도종남(Do Jong-Nam),김도형(Kim Do-Hyeong),천병식(Chun Byung-Sik) 대한토목학회 2007 대한토목학회 학술대회 Vol.2007 No.10

웹 기반의 복수 비디오 대여점 관리 시스템 설계

황의성(Eui-Sung Hwang),황원록(Won-Rock Hwang),강태구(Tae-Goo Kang),제원섭(Won-Sub Je),김정인(Jung-In Kim) 한국멀티미디어학회 2003 한국멀티미디어학회 학술발표논문집 Vol.2003 No.1

마술을 활용한 중학생 영어 학습 효과 연구

황의성(Hwang, Eui Seong),민찬규(Min, Chan Kyoo) 한국영어교과교육학회 2010 영어교과교육 Vol.9 No.3

This paper aims to investigate the effects of teaching English through magic to first grade middle school students. The experimental group and the control group were chosen based on their pretest results and were compared after 10-week treatments in the following two areas: academic achievement and affective domain. The results are as follows. First, the experimental group showed better performance in the post-test than the control group. In addition, a significant statistical difference in the post-test scores was also observed between the two groups. The post written test was composed of three parts: vocabulary, grammar, and reading comprehension. Among the three parts, the participants in the experimental group demonstrated the most noticeable improvement in reading comprehension. A significant statistical difference between the two groups occurred only in reading comprehension. Second, concerning affective domain, the subjects in the experimental group showed substantially enhanced interest and motivation, although they did not show as much confidence as interest. This result implies that using magic in English class is useful and effective to stimulate learners’ interest and intrinsic motivation. Third, according to questionnaire results collected from both the 31 participants and 15 secondary teachers who participated in the study, more than 50% of them responded that using magic in English class helped them greatly with their English learning and teaching respectively.

재하시험을 통한 초고강도 선단확장 PHC말뚝의 적용성 연구

황의성(Ui-Seong Hwang) 한국산학기술학회 2019 한국산학기술학회논문지 Vol.20 No.3

경제 규모의 확장으로 국가 산업이 점차 발전해 나갈수록 사회 인프라를 구축하기 위한 대형·초고층 구조물의 건설이 증가함에 따라 상부의 큰하중을 하부의 암반지지층까지 안전하게 전달할 수 있는 연구가 활발히 이루어지고 있다. 본 연구에서는 우리나라의 단단한 암반층을 활용하여 지지력을 극대화 할 수 있도록 PHC의 콘크리트 압축강도를 기존 80 MPa에서 110 MPa로 높인 초고강도PHC에, 말뚝의 선단을 확장시킨 선단확장PHC를 항타공법과 매입공법으로 시공한 후 재하시험을 통해 지지력의 경향성을 확인해 보았다. 항타공법을 사용하여 선단확장PHC의 지지력을 측정해 본 결과 주면마찰력이 일반 PHC에 비해 작게 나타났으며, Stet-up 효과도 미미하게 나타나 지지력 측면에서 우위를 가질 수 없었다. 그러나 매입공법 적용시 주면마찰력의 발휘 효과는 주면부와 지반의 간격이 넓어 시멘트페이스트가 밀실히 채워질 경우 지지력 증가효과가 기대된다. 또한 초고강도PHC가 일반PHC에 비해 높은 지지력이 나타났으며, 허용항타응력도 60% 이내로 나타나 좀 더 견고한 지반까지 안전한 시공이 가능하였다. 따라서 초고강도PHC의 높아진 강도를 활용하기 위해서는 말뚝의 선단부를 연암의 강도를 지닌 지반에 설계하는 것이 말뚝 본수를 크게 절감 할 수 있으며, 시공비 절감과 공기단축의 효과도 얻을 수 있을 것이다. As the national industry is developing gradually due to the expansion of the economic scale, the construction of large and super high-rise structures for building social infrastructure has been increasing, and studies have been conducted actively to transmit the large loads at the upper portion to the lower bedrock. In this study, the PHC was extended to an ultra-high strength PHC, which increased the concrete compressive strength of the PHC from the conventional 80 MPa to 110 MPa, and the PHC, which extended the tip of the pile. After construction with the driving method and injected pile method, the tendency of the bearing capacity was tested through a load test. Measurements of the bearing capacity of the extended PHC using the pile driving method revealed the main surface friction force to be smaller than that of the general PHC, and the stet-up effect was also insignificant. On the other hand, the effect of the friction force on the ground surface when the injected pile method was applied is expected to increase the bearing capacity when the gap between the main surface and the ground is wide and the cement paste is filled tightly. In addition, the ultrahigh strength PHC showed higher bearing capacity than the conventional PHC, and the permissible pile stress was less than 60%. Therefore, it is possible to reduce the number of piles and reduce the construction cost and effect of shortening the length of the pile by designing the tip of the pile on the ground with the intensity of soft rock as a method for utilizing the increased strength of the ultra-high strength PHC.

GaAs 벌크에서 전자의 과도 전송 특성

임행삼,황의성,심재훈,이정일,홍순석 ( Haeng Sam Lim,Eui Sung Hwang,Jae Hoon Shim,Jung Il Lee,Soon Seuk Hong ) 한국전기전자재료학회 1997 전기전자재료학회논문지 Vol.10 No.3

H.264 인터모드 결정 방법 개선에 관한 연구

공재웅,정재진,황의성,김태형,김두영,Gong, Jae-Woong,Jung, Jae-Jin,Hwang, Eui-Sung,Kim, Tae-Hyoung,Kim, Doo-Young 한국융합신호처리학회 2008 융합신호처리학회 논문지 (JISPS) Vol.9 No.4

In this paper, we propose a new method for improving the H 264 encoding process and motion estimation part. Our approach is a method to reduce the encoding running time through the omission of reference frame in the mode selection process of H 264 and an improvement of SAD computing process. To evaluate the proposed method, we used the H 264 standard image of QCIF size and TIN 4:2:0 format. Experimental results show that proposed SAD algorithm 1 can improve the speed of encoding runnung time by an average of 4.7% with a negligible degradation of PSNR. However, SAD algorithm 2 can improve the speed of encoding runnung time by an average of 9.6% with 0.98dB degradation of PSNR. 본 논문에서는 H 264 인코딩 과정 중 모드 결정 및 움직임 예측 부분의 개선을 위한 새로운 방법을 제안한다. 제안한 방법은 H 264 모드 결정 과정 중 참조 프레임의 선택 과정 생략과 모드 결정 기준의 하나인 SAD 연산과정의 개선을 사용하여 인코딩 과정에서 수행되는 연산량을 감소시켜 인코딩 수행시간을 절감하는 방법이다. 제안하는 방법의 성능 평가를 위하여 H 264 표준에서 제공되는 QCIF 사이즈, YUV 4:2:0 포맷의 영상을 이용하여 실험 영상을 만들어 적용하였다. 본 논문에서 제안한 방법을 적용한 결과 알고리즘 1은 약간의 화질 열화를 보이며 수행시간은 10프레임씩 인코딩 하였을 때 평균 4.7% 감소하였으며, 알고리즘 2는 약 0.98dB정도의 화질 열화를 보이지만 인코딩 수행시간은 평균 9.6% 감소하였다.

규산계 시멘트 주입재의 강도와 STPP의 상관관계

성화돈(Sung Hwa-Don),황의성(Hwang Yi-Sung),천병식(Chun Byung-Sik) 한국구조물진단유지관리학회 2007 한국구조물진단학회 학술발표회논문집 Vol.11 No.1

Portland cement and sodium silicate are widely used as the main components of the injection, which are used to prevent flow and improve ground condition. The main problem of the injection material is the leaching of the sodium hydroxite and silicate due to the limited reaction with the cement. In this paper, the effect of cement dydration retarder on the compressive strength of the sodium silicate-cement gel was studied. A series of tests, including digital-type testing machine, X-ray diffraction and scanning electron microscope were performed. Results were clearly demonstrated that the sodium tripolyphosphate(STPP), which was the cement hydration retarder in the test, significantly improved the initial strength of the homogel.

포구속도 계측 시스템의 정확도 분석

최주호(Ju Ho Choi),황의성(Eui Seong Hwang),박원우(Won Woo Park),홍성수(Sung Soo Hong),유준(Joon Lyou) 제어로봇시스템학회 1999 제어·로봇·시스템학회 논문지 Vol.5 No.1

Vinyl Polysiloxane 인상재를 이용한 이회 인상법에서 contaminants가 putty-wash 결합력에 미치는 영향

김무현,정창모,전영찬,황의성,Kim, Mu-Hyon,Jeong, Chang-Mo,Jeon, Young-Chan,Hwang, Hie-Seong 대한치과보철학회 1996 대한치과보철학회지 Vol.34 No.2

Numerous factors are known to affect the accuracy of elastomeric impression materials. Factor often overlooked is the quality of the bond between putty and wash during corrective reline impression technique. The putty-wash bond strength must be strong enough to over-come the local stress at putty-wash interface. It is not always possible to avoid saliva contamination in making corrective wash impres-sion. And putty preliminary impression material con be used as a template for provisional restoration. Human saliva and the residual monomer of autopolymerizing acrylic resin are thought to affect the bond strength and the failure type. This study examined the effect of contaminants like human saliva, and residual resin monomer on the putty-wash bond strength and the effectiveness of treatment. 1. Of the tested three brands of Vinyl Polysiloxane impession meterial, Express Exhibited the greatest bond strength followed by Eamix and Perfect showed the lowest putty-wah bond strength. 2. Coating the putty substrates with human saliva did not produce decreased failure load in all the breands of Vinyl Polysiloxane impression meterail. 3. Of the three brands of VPS impression material that were exposed to methhylmethacry-late resin(Jet), only the putty-wash bond strength of the Perfect group diminished signifi-cantly. Moreover, all the specimens from group C of Perfect exhibited adhesive failure. 4. Exposing the substrates to ethylmethacrylate resin(SNAP. diminished the putty-wash bond strength significantly. With Perfect and Examix, failure occurred cohesively through the light-body, whereas with Express, failure occurred adhesive-cohesively. 5. Removing approximately 1mm thickness of the contaminated putty interface was the most effective treatment in countering the undesirable effect caused by residual resin monomer. The putty-wash bond strength of the groups that were treated with 1mm even putty reduction was not significantly different from those of control groups. With Perfect and Examix, cleaning the specimens with gauze soaked in 70% isopropyl alcohol increased the putty-wash bond strength, but was not as effective as 1mm even reduction of contaminated putty substrates. With Express, 70% isoproryl alcohol treatment exhibi0ted comparable putty-wash bond strength to that of control group.

소독제가 개인용 트레이와 실리콘 인상재의 접착력에 미치는 영향에 대한 연구

김정한,정창모,전영찬,황의성,Kim, Jung-Han,Jeong, Chang-Mo,Jeon, Young-Chan,Hwang, Hic-Seong 대한치과보철학회 1996 대한치과보철학회지 Vol.34 No.2

The effects of impression tray disinfection procedures on the bond strength of impression-material adhesive to two of types resin trays were evaluated with a tensile test. Autopolyme-rizing acrylic resin was formed into 1x1x1 cm cubes. A hook was attached to each cube with autopolymerizing acrylic resin. Perforated trays were fabricated with stops to maintain an even 3 cm of impression material over the resin block. Hook on the opposite side of the perforated tray permitted attachment of the metal plate to a mechanical testing machine. Before adhesive was applied, one third of the resin specimens were immersed in a 5% sodium hypochlorite solution : one third in a 2% glutaradehyde solution, and one third were kept in the "as fabricated" condition. Three products(Perfect ups, Exafine, and Exp-ress) of polyvynil siloxane impression material-adhesive system were evaluated. The resin-impression material-metal plate couples were attached to a mechanical testing machine and tensile forces were applied at a separation rate of 10 centimeters per second. The results were as follows; 1. Both disinfectant and adhesive had effects on bond strength values, but adhesive had more effect than disinfectant(p<0.01). However, there was no interaction between dinin-fectant and adhesive(p>0.01). 2. Mean bond strength values for the Perfect materials were about 85% less than that of the Exafine or the Express materials. However, there was no stastically significant difference between the mean bond strength values of the Exafine materials and the Express materials(p>0.05). 3. The use of disinfectants produced significant reduction in bond strength values(p<0.05). But there was no stastically significant difference between the mean bond strength values of the groups treated with disinfectants(p>0.05).