해양구조물을 위한 유비쿼터스 기반의 혼합현실 유지보수 지원 시스템

이경호,이정민,김동근,한영수,Lee, Kyung-Ho,Lee, Jung-Min,Kim, Dong-Guen,Han, Young-Soo 한국전산구조공학회 2008 한국전산구조공학회논문집 Vol.21 No.6

IT기술의 발전에 따른 각종 산업에서의 유비쿼터스 도입이 이루어지고 있다 특히 자동차 산업에서 유비쿼터스 환경 도입을 위한 연구가 활발히 진행되고 있으며, BMW의 경우 유비쿼터스 환경 기반의 운전자지원시스템을 연구한바 있다. 조선산업에서 유비쿼터스 환경을 구축하고자 유비쿼터스 기반의 혼합현실을 제시한다. 혼합현실은 현실과 가상이 융합된 환경으로 현실에 기반을 두었을 때 증강현실이라고 하며, 이것은 현실세계에 가상의 물체를 오버랩하여 보여줌으로써 보다 현실감을 높여주는 기술이다. 따라서 본 논문에서는 해양구조물에서의 효과적인 검자 지원을 위하여 증강현실 기술을 활용하였으며 프로토 타입을 구축해 봄으로 그 활용 가능성을 판단해 보고자 한다. Ubiquitous has spotlighted in the industry in these days, and automotive industry has tried to build ubiquitous environment like as 'intelligent driver assistance system' in BMW Inc. even though in shipbuilding industry. As the part of Ubiquitous Technology for visualization, Mixed Reality has been adopted in this paper. Augmented reality, a part of mixed reality, could show the mixed real world, overlapping virtual objects. Therefore, it is more realistic than virtual reality that all generated by computer and it is very useful for displaying information. For this reason, we tried to apply augmented reality to inspect marine structure and we developed the inspection assistance system based on mixed reality

망막대형혈관환자에서 발생한 중심장액맥락망막병증

이경호,오재령,김성우,허걸,Kyung Ho Lee,Jaeryung Oh,Seong-Woo Kim,Kuhl Huh 대한안과학회 2013 대한안과학회지 Vol.54 No.7

Purpose: The relationship between central serous chorioretinopathy associated with retinal macrovessel remains controversial due to its rareness. We report a case of central serous chorioretinopathy diagnosed by spectral domain optical coherence tomography (SD-OCT) in a patient with a retinal macrovessel that improved spontaneously. Case summary: A 36-year-old healthy male patient visited our clinic complaining of blurred vision in his left eye. Fundus examination of the left eye revealed central serous chorioretinopathy with retinal macrovessel in the macular area. Fundus fluorescent angiography showed an ink blot-shaped leakage, which was not clearly distinguishable due to a retinal macrovessel. Serous retinal detachment under the neurosensory retina was identified on OCT. A small pigment epithelial detachment was observed and considered as a leaking point. However, no visible exudates appeared to be leaking around the retinal macrovessel. Conclusions: Central serous chorioretinopathy with a retinal macrovessel in a Korean patient was evaluated by SD-OCT. When compared with typical cases, no differences were observed in this case and no significant associations between central serous chorioretinopathy and retinal macrovessel were shown.

간헐외사시에서 1시간 또는 2시간으로 단축한 눈가림의 효과

이경호,서영우,조윤애,Kyung Ho Lee,Young Woo Suh,PhD,Yoon Ae Cho,PhD 대한안과학회 2014 대한안과학회지 Vol.55 No.4

Purpose: To evaluate the compliance level of therapy and the change in exo-angle after 1 or 2 hours of part-time occlusion therapy in intermittent exotropia. Methods: This retrospective study included 97 patients with intermittent exotropia who were followed-up for more than 6 months after their initial visit. We evaluated the exo-angle and prescribed either 1 hour or 2 hours of part-time occlusion therapy for the fixating eye. After 6 months, the exo-angle was reevaluated and compliance was examined. Patients were divided into 2 groups according to the occlusion therapy time: the 1-hour patching group (33 patients) and the 2-hour patching group (64 patients). Compliance and deviation angle were retrospectively reviewed and compared between the 2 groups. We evaluated the exo-angle of patients with compliance over 50% (1-hour patching group (31 patients), 2-hour patching group (51 patients)). Results: The mean exo-angles on the first visit were 22.61 ± 5.78 PD (prism diopters) at distance and 22.88 ± 8.11 PD at close-range in the 1-hour patching group, and 26.17 ± 4.55 PD at distance and 25.27 ± 8.54 PD at close-range in the 2-hour patching group. The proportion of patients with compliance over 50% was higher in the 1-hour patching group (93.94%) than in the 2-hour patching group (79.69%, <em>p</em> = 0.013). There were significant decreases in distant and close- range deviation angles after part-time occlusion in patients with compliance over 50% in both groups (1-hour patching group distant<em> p </em>= 0.042, close-range <em>p</em> = 0.002; 2-hour patching group distant <em>p</em> < 0.001, close-range <em>p</em> < 0.001). The magnitude of deviation angle decrease was not statistically significant between the 2 groups (ANCOVA; distant p = 0.461, near <em>p</em> = 0.761). Conclusions: One or 2 hours of part-time occlusion therapy in intermittent exotropia provided beneficial effects, including decreasing the deviation angle. The magnitude of deviation angle decrease, however, was not different between the 2 times of therapy. Compliance was higher in the 1-hour part-time occlusion therapy group. Therefore, 1-hour part-time occlusion therapy could be effective in patients with poor cooperation. J Korean Ophthalmol Soc 2014;55(4):585-589

경량골재 콘크리트 배합 및 시공의 리뷰

이경호,양근혁,Lee, Kyung-Ho,Yang, Keun-Hyeok 한국건설순환자원학회 2017 한국건설순환자원학회지 Vol.12 No.3

선박 안전성 평가 및 구난지원 시스템

이경호,이동곤,Kyung-Ho Lee,Dong-Kon Lee 대한조선학회 1999 大韓造船學會 論文集 Vol.36 No.3

선박의 사고는 인명과 재산의 손실뿐만 아니라 사고 선박으로부터 유출되는 기름과 유해한 산적 화물에 의한 환경 오염을 초래하기 때문에 사고를 미연에 방지하는 것 뿐 만 아니라, 사고가 발생하였을 때 이에 신속히 대처함으로써 오명을 최소화하고 2차 사고의 위험을 줄이는 것이 매우 중요한 문제이다. 그러나 지금까지의 기술적 지원이 결여된 경험위주의 대처 방법으로는 사고선박에 대한 구난을 안전하고 신속하게 처리하기가 쉽지 않다. 본 연구에서는 체계적이고 과학적인 구난지원 도구를 개발하여 이를 사고 현장의 구난지원 작업에 투입하고자 한다. 이를 위하여 구난지원 체계를 구축하고, 프로토타입 시스템을 개발하여 사고선박에 대한 안전하고 신속한 구난지원 가능성을 검토하였다. Marine casualties of dangerous cargo carriers lead to not only the loss of human life and properties, but also marine pollution caused by spilled oil and hazardous cargo. So the prevention of marine casualties and emergence response to minimize pollution are very important problems to be settled. But until now, most of salvage assistance jobs have been done based on rule of thumb without any technical support. It is not easy to cope with the incidents safely and rapidly under the current situation. The purpose of this paper is to develop a systematic and engineering salvage assistance tool available in the casualty sites. This paper contains the construction of salvage system, classification of technical items, and prototype system for the safety assessment. The developed system enable a salvage engineer in his/her salvaging jobs to perform safely and promptly.

RDA에 바탕한 저작의 집중화 방안 연구 - KORMARC의 24X필드 기술을 중심으로 -

이경호,Lee, Kyung-Ho 한국도서관정보학회 2014 한국도서관정보학회지 Vol.45 No.1

본 연구는 서지기술의 국제적 표준으로 등장한 RDA의 설계취지를 반영하여 KORMARC의 24X 필드를 중심으로 정보검색결과 저작의 집중화 방안에 대해 다룬다. 이를 위해 한국문헌자동화 목록형식인 KORMARC 시스템에서 24X필드의 데이터 입력방법을 분석하여 문제점을 밝혀내고, 이를 해결할 수 있는 방안을 제안한다. 저작의 집중화 방안에는 (1) 관제표기 방법의 개선, (2) 통일표제 사용방법의 개선, (3) 부호가 사용된 표제의 기술방법 개선 등이다. 이를 통해, 이용자들은 MARC 데이터베이스로부터 원하는 정보를 전방일치 검색으로 효과적으로 검색 할 수 있으며, 검색결과가 집중화되어 자료를 식별하는데 보다 용이할 수 있음을 밝혀냈다. This study makes some suggestions to cluster works from the search result of library databases. Specifically, the author suggests modifying the current practices and rules of KORMARC 24X field based on intent of RDA, which is the new cataloging standard. After identifying some problems in entering bibliographic data into 24X field, the author proposes solutions to such problems. The solutions include improvements in (1) Goanje description (관제기술), (2) use of uniform title, and (3) processing of marks, etc. The study demonstrates that users can conduct a fronted keyword searching effectively and identify the relevant bibliographic records easily from the clustered search results.

콜론분류법에 바탕한 자동분류시스템의 개발에 관한 연구 - 농학 및 의학 전문도서관을 사레로 -

이경호,Lee Kyung-Ho 한국문헌정보학회 1992 한국문헌정보학회지 Vol.23 No.-

The purpose of this study is (1) to design and test a database which can be automatically classified, and (2) to generate automatic classification number by processing the keywords in titles using the code combination method of Colon Classification(CC) as well as an automatic recognition of subjects in order to develop an automatic classification system (Auto BC System) based on CC which can be applied to any research library. To conduct this study, 1,510 words in the fields of agricultrue and medicine were selected, analized in terms of [P], [M], [E], [S], [T] employed in CC, and included in a database for classification. For the above-mentioned subject fields, the principle of an automatic classification was specified in order to generate automatic classification codes as well as to perform an automatic subject recognition of the titles included. Whenever necessary, editing, deleting, appending and reindexing of a database can be made in this automatic classification system. Appendix 1 shows the result of the automatic classification of books in the fields of agriculture and medicine. The results of the study are summarized below. 1. The classification number for the title of a book can be automatically generated by using the facet principles of Colon Classification. 2. The automatic subject recognition of a book is achieved by designing a database making use of a globe-principle, and by specifying the subject field for each word. 3. The automatic subject-recognition of input data is achieved by measuring the number of searched words by each subject field. 4. The combination of classification numbers is achieved by flowcharting of classification formular of each subject field. 5. The efficient control of classification numbers is achieved by designing control codes on the database for classification. 6. The automatic classification by means of Auto BC has been proved to be successful in the research library concentrating on a Single field. The general library may have some problem in employing this system. The automatic classification through Auto BC has the following advantages: 1. Speed of the classification process can be improve. 2. The revision or updating of classification schemes can be facilitated. 3. Multiple concepts can be expressed in a single classification code. 4. The consistency of classification can be achieved with the classification formular rather than the classifier's subjective judgement. 5. A user's retrieving process can be made after combining the classification numbers through keywords relating to the material to be searched. 6. The materials can be classified by a librarian without subject backgrounds. 7. The large body of materials can be quickly classified by means of a machine processing. 8. This automatic classification is expected to make a good contribution to design of the total system for library operations. 9. The information flow among libraries can be promoted owing to the use of the same program for the automatic classification.

선박 블록 정합을 위한 포인트 클라우드 기반의 오차예측 방법에 대한 연구

이경호,이정민,남병욱,김대석,Lee, Kyung-Ho,Lee, Jung-Min,Nam, Byeong-Wook,Kim, Dae-Seok 한국전산구조공학회 2016 한국전산구조공학회논문집 Vol.29 No.2

선박 건조 시장의 요구를 맞추기 위하여 신속한 건조의 목표로 노력하고 있는 조선소가 선박 정도관리에 대한 요구가 갈수록 높아지고 있다. 선박 건조 공정에서 생산성의 향상과 생산 주기의 단축을 위하여 선박 부재의 정도평가를 전 주기에서 수행해야 하는 것은 중요하다. 선박의 품질을 높이기 위하여 조선소에서 블록의 정도제어를 수행하는 것은 선박의 건조 주기를 단축할 수 있을 뿐만 아니라 건조 비용도 줄일 수 있다. 선박 블록의 정도를 제어하는 중심은 선박 블록 통합 정도관리 시스템을 만들어야 한다. 이 시스템은 "Non-allowance Shipbuilding"의 목표로 정도관리의 총괄성, 블록 정도의 향상, 정도 관리 과정의 표준화 등이 이루어져야 한다. 일반적으로 정도관리를 수행하는 관리자가 광파측정기를 이용하여 선박 블록의 접합면에 있는 주요 포인트(vital point)를 측정하고 수집하지만 무거운 계측장비를 가지고 블록의 정도관리를 수행하는 것은 불편할 뿐만 아니라 시간도 오래 걸린다. 본 논문에서는 선박 블록의 정도관리 시간을 단축할 수 있는 포인트 클라우드 기반으로 3차원 레이저 스캐너를 이용한 선박 블록 탑재 전에 오차예측 방법을 제안하였다. 이 방법은 ICP(iterative closest point) 알고리즘으로 측정된 포인트 클라우드와 설계된 점들의 비교 작업을 수행한 다음에 허용범위 내의 오차를 만족하는 지를 판단한다. With the development of fast construction mode in shipbuilding market, the demand on accuracy management of hull is becoming higher and higher in shipbuilding industry. In order to enhance production efficiency and reduce manufacturing cycle time in shipbuilding industry, it is important for shipyards to have the accuracy of ship components evaluated efficiently during the whole manufacturing cycle time. In accurate shipbuilding process, block accuracy is the key part, which has significant meaning in shortening the period of shipbuilding process, decreasing cost and improving the quality of ship. The key of block accuracy control is to create a integrate block accuracy controlling system, which makes great sense in implementing comprehensive accuracy controlling, increasing block accuracy, standardization of proceeding of accuracy controlling, realizing "zero-defect transferring" and advancing non-allowance shipbuilding. Generally, managers of accuracy control measure the vital points at section surface of block by using the heavy total station, which is inconvenient and time-consuming for measurement of vital points. In this paper, a new measurement method based on point clouds technique has been proposed. This method is to measure the 3D coordinates values of vital points at section surface of block by using 3D scanner, and then compare the measured point with design point based on ICP algorithm which has an allowable error check process that makes sure that whether or not the error between design point and measured point is within the margin of error.

현장 품질관리를 고려한 경량골재 콘크리트의 시방서 개정안에 대한 고찰

이경호,양근혁,Lee, Kyung-Ho,Yang, Keun-Hyeok 한국건축시공학회 2018 한국건축시공학회지 Vol.18 No.3

이 연구에서는 국내산 인공 경량골재를 사용한 콘크리트의 실험결과를 바탕으로 콘크리트 표준시방서의 관련내용에 대한 합리성 및 개정의 필요성을 평가하였다. 국내 표준시방서의 내용은 ACI 211.2, ACI 213, ACI 301, JASS 5 및 CEB-FIP 시방내용들과 비교하였다. 국내산 인공 경량 잔골재의 연속적 입도분포를 위해서는 최대직경 2.5mm 이하의 천연모래 혼입이 요구되었다. 경량골재 콘크리트의 재료분리 및 과도한 블리딩을 제어하기 위해서는 현재 시방서에서 제시된 최대 물-결합재비와 단위수량에 대한 수정이 요구되었다. 특히, 배합 목표성능인 초기 슬럼프, 28일 압축강도, 공기량 및 기건 단위용적중량에 대해 경량골재 콘크리트의 합리적인 배합설계 절차의 확립이 요구되었다. 결과적으로 콘크리트 표준시방서는 국내산 인공 경량골재의 특성을 고려하여 전반적이 개정이 요구되었다. This study examined the reliability and revision necessity of concrete standard specifications based on the comparisons with test data obtained by using domestic artificial lightweight aggregates and the contents specified in different foreign specifications including ACI 211.2, ACI 213, ACI 301, JASS 5 and CEB-FIP. To achieve the continuous particle distribution of domestic fine lightweight aggregates, the partial addition of natural sand with the maximum size of 2.5mm was required. To control the segregation and excessive bleeding in the fresh lightweight concrete, the current limitations on the water-to-binder ratio and unit water content need to be modified using lower values. In particular, a rational mixture proportion approach of lightweight concrete needs to be established for the targeted requirements of initial slump, 28-day compressive strength, air content and dry unit weight. Ultimately, significant revision of the concrete standard specifications is required considering the characteristics of domestic artificial lightweight aggregates.

방사선조사가 백서 구치 법랑질형성에 미치는 영향에 관한 주사전자현미경적 연구

이경호,박태원,Lee Kyung-Ho,Park Tae-Won 대한영상치의학회 1995 Imaging Science in Dentistry Vol.25 No.2

The purpose of this study was to investigate the effects of radiation on the formation of rat molar enamel at the developmental stage. The experimental animals were divided into five groups and were irradiated single dose of 396cGy ; 1 st group on 14th day of gestation, 2nd group on 19th day of gestation, 3rd group on 3 days after birth, 4th group on 8 days after birth, 5th group on 28 days after birth. The control and 1, 2, 3, and 4th experimental groups were sacrificed on 2, 4, and 6 weeks and the 5th groups were sacrificed on 1 day and 2 weeks after irradiation. Distal 1/2 and occlusal 1/3 enamel surface of lingual side of lingual cusp, and fractured surface of lingual side of lingual cusp in a longitudinal direction of the mandibular first molar were examined using scanning electron microscope. The following results were obtained. 1. The roughness of enamel surface and enamel hypoplasia were increased in a sequence of 4th, 1st, 2nd, and 3rd experimental group, and the enamel cracks were increased in the 1st and 2nd experimental group. 2. The pattern of enamel hypoplasia had a network form on the 1st and 2nd experimental group, and appeared a linear shape on the 3rd experimental group, and then the crator-like enamel defects were observed in all experimental groups (especially 1st and 2nd experimental group) except 5th. 3. Dentinoenamel junction showed the clear-cut and straight appearance except 5th experimental group. 4. There was no significant difference between 5th experimental and control group.