지진조기경보를 위한 신속 진앙위치 결정

김광희,석봉출,Kim. Kwang-Hee,Rydelek. Paul A.,Suk. Bong-Chool 한국방재학회 2008 한국방재학회논문집 Vol.8 No.6

경제규모의 증가, 산업화, 도시화 등은 결과적으로 우리국민의 잠재적 지진 위험 증가를 야기하였다. 최근에는 비록 우리나라에서 지진으로 인한 인명과 재산의 손실이 미비했지만, 과거 문헌 기록을 보면 우리나라에서도 대규모 피해를 야기한 지진이 발생한 바 있었으므로, 향후 피해를 유발할 수 있는 지진발생 가능성을 간과할 수는 없다. 현재의 과학기술력으로는 단기 지진 예보가 불가능함을 고려할 때 지진재해 저감을 위하여 취할 수 있는 대비책의 하나로써 지진조기경보체계 확립의 중요성이 점차 증가하고 있다. 지진조기경보체계 확립의 취지는 지진발생 후 강진동이 시작하기 전 수 초 혹은 수십 초의 지진대비시간을 확보하고 미리 계획된 조치를 취함으로써 지진재해를 저감하는 것이다. 본 논문에서는 신속한 지진 발생위치 결정을 위하여 진원 부근 2개의 지진 관측소에서 확보한 초동 도착시간과 주변의 다른 관측소에서는 아직 초동이 관측되지 않았다는 사실을 이용한다. 우리나라 내륙 및 주변해역에서 발생한 주요 지진의 신속한 진앙 위치결정에 이 기술을 적용하였다. 관측소 외부에서 지진이 발생할 경우 이 기술로는 효과적인 지진위치의 결정이 어렵지만, 관측망 내부에서 지진이 발생할 경우 본 기술을 이용하여 지진의 위치를 신속히 결정 할 수 있다. 수도권의 경우 <TEX>$10{\sim}50$</TEX>초의 지진대비시간을 확보할 수 있을 것으로 예상되며, 주어진 시간 내에 사전 준비된 조치를 취함으로써 유사시 지진재해저감에 크게 기여할 것이다. Economic growth, industrialization and urbanization have made society more vulnerable than ever to seismic hazard in Korea. Although Korea has not experienced severe damage due to earthquakes during the last few decades, there is little doubt of the potential for large earthquakes in Korea as documented in the historical literature. As we see no immediate promise of short-term earthquake prediction with current science and technology, earthquake early warning systems attract more and more attention as a practical measure to mitigate damage from earthquakes. Earthquake early warning systems provide a few seconds to tens of seconds of warning time before the onset of strong ground shaking. To achieve rapid earthquake location, we propose to take full advantage of information from existing seismic networks; by using P wave arrival times at two nearest stations from the earthquake hypocenter and also information that P waves have not yet arrived at other stations. Ten earthquakes in the Korean peninsula and its vicinity are selected for the feasibility study. We observed that location results are not reliable when earthquakes occur outside of the seismic network. Earthquakes inside the seismic network, however, can be located very rapidly for the purpose of earthquake early warning. Seoul metropolitan area may secure <TEX>$10{\sim}50$</TEX> seconds of warning time before any strong shaking starts for certain events. Carefully orchestrated actions during the given warning time should be able to reduce hazard and mitigate damages due to potentially disastrous earthquakes.

실리콘 이온주입 SiO₂층의 나노결정으로 부터의 광루미네센스

김광희,오항석,장태수,권영규,이용현,Kim, Kwang-Hee,Oh, Hang-Seok,Jang, Tae-Su,Kwon, Young-Kyu,Lee, Yong-Hyun 한국센서학회 2002 센서학회지 Vol.11 No.3

Photoluminescence(PL) properties of $Si^+$-implanted $SiO_2$ film, which was thermally grown on c-Si substrate, is reported. We have compared room temperature photoluminescence (PL) spectra of the samples which was made in several kinds of implantation, subsequent annealing and $SiO_2$ film thickness. XRD data was correlated with the PL spectra. Silicon nanocrystals in $SiO_2$ film is considered as the origin of the photoluminescence. PL spectra was investigated after wet etching of the $SiO_2$ film by using BOE (Buffered Oxide Etchant) at every one minute. PL peak wavelength was varied as the etching is proceeded. These results indicate that the quantity and the distribution of dominant size of Si nanocrystals in $SiO_2$ film seem to have a direct effect on PL spectrum.

일부 성인의 구강건강 지식이 구강건강 증진 행위에 미치는 영향

김광희,정윤숙,Kim, Kwang-Hee,Jung, Yun-Sook 한국치위생학회 2021 한국치위생학회지 Vol.21 No.2

Objectives: This study aimed to investigate oral health-related knowledge in adults and to determine the effect of oral health knowledge on correct brushing and use of dental care products. Methods: The subjects of this study were 552 adults who visited dental clinic, and a self-administered questionnaire was administered. Statistical analysis was performed using the t-test, ANOVA, and multiple regression using the SPSS statistics program (ver. 23.0, IBM Co., Chicago, IL, USA). Results: The oral health knowledge level, correct brushing, and dental care product usage scores were found to be positively correlated (r=0.015, 0.016), and both correlation coefficients were statistically significant (p<0.05). Oral health knowledge was found to have a significant effect on correct brushing among oral health promotion behaviors (β=0.116, p=0.006), but it was not found to have a significant effect on the use of dental care products (β=0.053, p=0.214). Conclusions: Oral health promotion behavior is closely related to oral health knowledge, and it is thought that oral health promotion behavior can be improved by raising oral health knowledge levels.

Hydroxyl Ionization and Iodination of Tyrosine Residues in ${\alpha}$-Amylase

김광희,양철학,최명언,Kwang Hee Kim,Chul-hak Yang,Myung-un Choi Korean Chemical Society 1992 대한화학회지 Vol.36 No.4

확률적 표본추출 방법을 이용한 집단 약동학 모형의 추정과 검증에 관한 고찰

김광희,윤정화,이은경,Kim, Kwang-Hee,Yoon, Jeong-Hwa,Lee, Eun-Kyung 한국통계학회 2015 응용통계연구 Vol.28 No.2

This study is about estimation methods for the population pharmacokinetic and pharmacodymic model. This is a nonlinear mixed effect model, and it is difficult to find estimates of parameters because of nonlinearity. In this study, we examined theoretical background of various estimation methods provided by NONMEM, which is the most widely used software in the pharmacometrics area. We focused on estimation methods using a stochastic sampling approach - IMP, IMPMAP, SAEM and BAYES. The SAEM method showed the best performance among methods, and IMPMAP and BAYES methods showed slightly less performance than SAEM. The major obstacle to a stochastic sampling approach is the running time to find solution. We propose new approach to find more precise initial values using an ITS method to shorten the running time.

공구접근 경로가 밀링 가공된 원통 구멍 형상에 미치는 영향

김광희,Kim, Kwang-Hee 한국기계가공학회 2004 한국기계가공학회지 Vol.3 No.4

Because of the development in mold industries, the geometrical form accuracy of the milled surface is getting more and more important. It has been known that the geometrical form accuracy is affected by machine conditions, cutting conditions, tool conditions and tool path and so on. Among them, the tool approaching path causes the change in material removal per tooth at the end of each machining cycle. And, this change generates the geometrical form error around the region where the tool engages the workpiece initially. So, it is impossible to eliminate the geometrical error caused by the tool approaching path. Thus, characteristics of this geometrical error are studied analytically and experimentally to minimize this region.

A study on the grinding characteristics of the workpiece using the laminated grinding wheel in the cylindrical grinding process

김광희,이은종,김강,Kim, Kwang-Hee,Lee, Ewn-Jong,Kim, Kang The Korean Society of Manufacturing Technology Eng 2000 한국공작기계학회지 Vol.9 No.5

To get smoother ground surface, it is required to replace the grinding wheel with a finer-grit wheel. When the operator replaces the grinding wheel, the balancing and dressing of the wheel surface are necessary. So this replacement has a lot of problems like inconvenience to operators, delays in the operation time, and ineffectiveness in the production process. Therefore, a laminated grinding wheel, which consists of three layers, is provided. The side layers are coarse grits and the middle layer is made up of fine grits. To show the effectiveness of the laminated grinding wheel, experiments on the surface roughness and the material removal rate were performed respectively. As a result, it was found that the grinding process using a laminated grinding wheel can generate smoother ground surface in shorter time.

역공학기반의 프레스 부품 변형 보정에 관한 연구

김광희(Kim, Kwang-Hee),이윤영(Lee, Yun-Young) 한국산학기술학회 2013 한국산학기술학회논문지 Vol.14 No.1

본 연구에서는 프레스 부품의 스프링 백을 보정하기 위한 새로운 방법론을 제안하였다. 먼저, CAD 데이터 와 측정데이터 사이의 오차를 비교하였다. 새로운 방법은 스프링 백을 보정하기 위한 수동적인 모델링 공정 대체가 가능한 3차원 측정데이터 기반의 자동 모델링을 제안하였다. 본 연구를 통해 프레스 부품의 스프링 백 보정을 위한 새로운 방법론을 적용하면 실제 공정에 소요되는 시간 및 비용 절감이 가능할 것으로 기대된다. In this study, we suggested new method for compensation on spring back of press part. At first, we compared between error on CAD data and scanning data. The new method can be substituted for manual modeling process in compensation on spring back. The new method is available for automatic modeling based on 3D scanning data. From the study, the results expect that time and cost reduction for process applying new method for compensation on spring back of press part.

Bit 설계형상의 굴진성능에 관한 연구

김광희(Kim, Kwang-Hee),이윤영(Lee, Yun-Young) 한국산학기술학회 2012 한국산학기술학회논문지 Vol.13 No.10

본 연구에서는 지반시추용 드릴비트의 설계를 검증하기 위해 유한요소 해석을 수행하였다. 드릴비트 해석결 과와 실제 굴진시험장비의 실험결과와 비교하여 해석의 타당성을 검증하였다. 본 연구를 통해 드릴비트의 다양한 형 상, 재료 물성치 선정을 위해 유한요소해석을 활용하여 실제 실험에 소요되는 시간 및 비용 절감이 가능할 것으로 기대된다. In this study, we carried out finite element analysis for drill bit design on ground boring. We verified analysis between drill bit analysis results and experiment results of test machine. From the study, the results expect that time and cost reduction for experiment using finite element analysis for determination on drill bit geometry and material property.

촉감시스템의 부식패턴을 적용한 실리콘 금형 개발

김광희(Kim, Kwang-Hee),김정식(Kim, Jeong-Sig) 한국산학기술학회 2012 한국산학기술학회논문지 Vol.13 No.9

본 연구에서는 시작형 몰드재료인 실리콘 레진(RTV-3040)을 이용하여 엠보패턴을 활용한 몰드금형 개발을 위한 것이며, 상용패키지(Freeform)를 사용하여 필요한 패턴을 선택 한 후 면에 투영 엠보 면을 만들어 부품에 적용 가능을 검토하였다. 소량의 부품 개발 시 부식패턴이 필요로 한 제품들은 알루미늄 금형과 같은 시작형을 제작하여 대응하였으나, 부식패턴을 적용한 실리콘 금형 개발로 시간단축 및 원가절감이 가능한 것으로 나타났다. In this study, the start-type molded material, silicone resin(RTV-3040) was used to develop a mold that is utilized for embossing pattern. After selecting a required pattern using the commercial package (Freeform), we examined whether this is applicable to components creating projective embossed side on the surface. We responded to products that require corrosive pattern, such as aluminum mold, by making the starting type when small amounts of components are developing. However, the development of silicone mold that is applied to corrosive pattern showed the possible reduction in time and cost