Hybrid Control Method of Near-Field Scanning Optical Microscope for Characterization of Optical Waveguide Devices

Wonsoo Ji,Seung Gol Lee,Beom-hoan O,El-Hang Lee,Se-Geun Park,Seoung Jun Jang 한국물리학회 2005 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.47 No.1

Although both the topological information and the propagating characteristics of an optical waveguide device can simultaneously be measured with a Near-field Scanning Optical Microscope (NSOM), the structural distinctiveness of the device makes the height control of NSOM difficult. In order to resolve this difficulty, the hybrid method of controlling the gap between the NSOM probe and the device surface is newly proposed, this being based on the combination of a digital and an analog control method. It is shown that the proposed method is very efficient and stable in measuring a waveguide device with abrupt step coverage.

NSOM-based characterization method applicable to optical channel waveguide with a solid-state cladding

Wonsoo Ji,Daechan Kim,Hyun Jun Kim,Beom-Hoan O,Se-Geun Park,El-Hang Lee,Seung Gol Lee IEEE 2005 IEEE photonics technology letters Vol.17 No.4

<P>A new characterization method employing near-field scanning optical microscope (NSOM) is proposed to measure the propagation characteristics of an optical channel waveguide having a solid-state cladding. For the measurement, the cladding material is replaced with the liquid having the same refractive index as that of the removed cladding. Replacing the solid-state cladding with the liquid enables the NSOM probe to reach the core-cladding interface without changing the boundary condition at the interface. The height of the probe immersed into the viscous liquid is done with the information from the surface profile of the naked core. The measured propagation characteristic shows a good agreement with the simulation result.</P>

파라메트릭 건축의 기술적 변화에 따른 디자이너의 역할

이원수 ( Lee Wonsoo ) 한국공간디자인학회 2021 한국공간디자인학회논문집 Vol.16 No.4

(연구배경 및 목적) 컴퓨팅 기술의 발달과 3차원 모델링 툴의 지원으로 파라메트릭 건축은 기존의 건축에서 볼 수 없었던 비정형의 형태를 자유롭게 구현할 수 있게 되었다. 디자이너는 그래스호퍼, 다이나모와 같은 3차원 모델링 소프트웨어의 플러그인을 사용하여 특정한 매개변수를 입력하고 통제함으로써 디자인의 의도를 시각화한다. 현대의 파라메트릭 건축은 형태구성 뿐만 아니라 BIM 설계기법을 활용한 성능기반설계의 영역으로까지 확장하여 건축분야 간 매개변수의 간섭과 공유가 활발히 이루어진다. 이렇듯 복합적이고 다층화 된 현대 건축의 흐름 속에서, 알고리즘을 구성하고 매개변수를 통제하는 디자이너의 역할은 설계프로세스상에서 더욱 중요시 되고 있다. 이에 본 연구에서는 파라메트릭 건축에서 매개변수를 통제하고 디자인 의도를 시각화하는 건축 디자이너의 역할과 방향성에 대하여 말하고자 한다. (연구방법) 매개변수와 파라메트릭 건축 사이의 상호작용을 확인하기 위하여 파라메트릭 건축의 흐름을 초기부터 중기 이후까지 살펴본다. 또한, 국내·외 파라메트릭 건축물의 사례를 통하여 비정형 건축 디자인을 형태구성적 측면뿐만 아니라 공학적 측면에서도 분석하여 건물성능시뮬레이션이 파라메트릭 디자인에 미치는 영향에 대해서도 살펴보려 한다. 이를 통하여 매개변수와 파라메트릭 건축의 상관관계를 밝히고 매개변수를 입력하고 통제하는 디자이너의 역할과 방향성을 제고한다. (결과) 심미적 실험에 중점을 둔 초기의 파라메트릭 건축은 다양한 외적 매개변수를 정의하여 형태구성의 의외성과 모호성을 추구하였다. 디자이너는 비물질적인 가상세계를 생성의 장으로 하여 매개변수를 관념화하고 디자인 의도를 은유적이고 수사적으로 표현하였다. 하지만 대지와 주변 환경과의 관계 맺기와 같은 현실적이고 인간적인 의미의 소통이 필요하다는 디지털 건축에 대한 철학적 비판은 파라메트릭 건축이 해결해야 하는 중요한 과제로 남게 되었고 디자이너는 이 맥락적 단절을 극복하기 위한 고민을 하지 않을 수 없게 되었다. 공학적 성능실험과 현실적 구현이 가능해진 중기 이후의 파라메트릭 건축은 더욱 고도화되고 세분화되어 매개변수의 범위가 방대해졌고 알고리즘의 구조도 복잡해 졌다. 데이터의 흐름과 매개변수를 관리하는 디자이너의 역할은 BIM과 같이 분야 간 간섭과 상호작용이 활발한 설계 프로세스상에서 필수적이 되었다. (결론) 문헌과 사례분석을 통하여 연구한 파라메트릭 건축은 매개변수를 통하여 형태와 성능의 문제를 다루고 있음을 알 수 있다. 이 기술적 산물인 파라메트릭 건축에서 맥락의 단절과 소통의 부재는 디자이너가 매개변수에 적극적으로 개입함으로써 극복될 수 있다. 이를 통하여 파라메트릭 건축은 대지와 소통하고 주변 환경과의 인간적인 관계를 맺을 수 있다. (Background and Purpose) Parametric architecture generates unprecedentedly introduced non-linear form in virtue of advancement of both computing technology and 3D modeling software. Using 3D modeling software plug-in such as Grasshopper and Dynamo, designer visualizes design intent by inputting and controlling specific parameter. Contemporary parametric architecture, besides form making, extends its realm to performance-based design utilizing BIM technique, so that parameter sharing and data interference among architectural disciplines actively occur in this complex and multi-layered system. Thus, the role of designer, organizing algorithm and controlling parameter, becomes much more important in the process of design. This study highlights the role of architectural designer and its direction. (Method) The trend of parametric architecture was analyzed in order of time from its nascence to middle period and afterwards, so as to identify interrelationship between parametric architecture and its embryo, parameter. Also, non-linear architectural design was analyzed through case studies not only from form-making perspective but from engineering perspective, so as to identify the impact of building performance simulation on parametric design. Through this analysis, consequently, interrelationship between parametric architecture and parameter is identified, so that the awareness of the role of designer, that is to input and control parameters, is further raised. (Results) Early parametric architecture focuses on aesthetic experiment to seek emergence and ambiguity on form-making by administering external parameters. By conceptualizing these parameters with his own interpretation, designer expresses design intent either rhetorically or metaphorically on the generation field of dematerialized virtual world. However, philosophical criticism on digital architecture, that it is of absent from interrelation with environment to which requires realistic and humane attachment, has been left an assignment behind parametric architecture. Subsequently thereafter, designer cannot help considering ways to overcome this contextual schism. Parametric architecture in its middle period and afterwards was able to construct non-linear form in real world with the help of engineering performance analysis, which contributes to parameters widening its range and structure of algorithm being organized in much more complex way. In result, the role of designer, that is to control parameters and data flow, becomes critical in highly advanced and segmentalized design process such as BIM where interdisciplinary interference and interaction in between actively occur. (Conclusions) The result of this study on parametric architecture, investigated through literature and case analysis, suggested that parametric architecture deals with form and performance by means of parameter. The contextual schism and absence of communication in this technological achievement of parametric architecture is able to be overcome by designer engaging actively in parameter. Through this responsible role of designer, parametric architecture is able to communicate with the earth and establish humane relationship with environment.

선박 기반 HNS 리스크 제어 기술 개발에 관한 연구

이은방(Eun-bang Lee),윤종휘(Jong-hwui Yun),정민기(Mingi Jeong),홍경의(Kyeong-eui Hong),이문진(Moonjin Lee),강원수(Wonsoo Kang) 한국해양환경·에너지학회 2018 한국해양환경공학회 학술대회논문집 Vol.2018 No.5

Heterogeneous Logit Model 을 이용한 광역수도권의 주택유형 및 교통수단 선택에 관한 연구

이진원(JinWon Lee),김원수(WonSoo Kim),주현태(HyunTai Choo) 한국지역개발학회 2001 韓國地域開發學會誌 Vol.13 No.1

This study aims to improve the statistical precision of aggregate probabilistic choice model. Models are applied in the choice of housing and transportation mode affected by the rapid change of the structure in the metropolitan capital area. The data are 3,176 effective ones sampled from population of the capital area. The major findings are as follows. First, a choice of housing and transportation mode is discussed employing Multinominal Logit Model as a basic model. The results of estimation are quite well in accordance with those of existing studies. Second, Nested Logit Model encompassing Multinominal Logit Model is analyzed to test the validity of Multinominal Logit Model. Nested Logit Model is an appropriate model since an Inclusive Value is significantly different from 1. The signs of most variables are desirable and the coefficients are statistically significant. In applying Nested Logit Model, Limited Information Maximum Likelihood method (LIML) has usually been used. LIML is, however, less efficient than Full Information Maximum Likelihood method (FIML). This study obtains better efficiency by using FIML. Third, as the highlight of this study, two strong assumptions of Nested Logit Model are relaxed; the constant similarity and homoskedastic error terms. The validity of Heterogeneous Logit Model with the flexible similarity and heteroskedastic error terms is confirmed. This study shows that Heterogeneous Logit Model could enhance the statistical precision of probabilistic choice model.

해양산업시설 배출 위험유해물질(HNS)의 위해성평가기반 수질준거치설정 체계 제안

최훈(Hoon Choi),강원수(Wonsoo Kang),김태원(Tae-Won Kim),이문진(Moonjin Lee) 한국해양환경·에너지학회 2022 한국해양환경·에너지학회지 Vol.25 No.4

해양산업시설의 위험유해물질 해양배출 규제체계 개선의 필요성과 규제방향에 대한 연구

이문진,김계원,강원수,Lee, Moonjin,Kim, Kyewon,Kang, Wonsoo 해양환경안전학회 2021 해양환경안전학회지 Vol.27 No.6

In this paper, the current status of marine industrial facilities, regulatory legal systems, and emission status of hazardous and noxious substances (HNS) in these facilities were analyzed, and the direction of improvement of the regulatory system was presented accordingly. As a result of the analysis, it is estimated that about 1,100 marine industrial facilities are subject to the Marine Environment Management Act of 2007. It is estimated that 190 kinds of hazardous substances are discharged from these marine industrial facilities and are highly likely to flow into the ocean, of which 20 are estimated to be discharged into the water system. However, due to the lack of relevant laws and regulation, it is difficult to clearly determine whether the discharged material corresponds to an exceptional discharged material, making it difficult to effectively enforce regulations in the field. For this reason, effective regulatory enforcement is difficult in the regulatory field. The marine environment management law should clearly stipulate the exceptional emission standards and types of substances, and clarify the selection system, risk assessment system, and emission information collection and monitoring system for related Hazardous and Noxious Substances. 본 논문에서는 해양산업시설 현황과 규제법규 체계, 그리고 이들 시설의 위험유해물질 배출실태 등을 분석하고, 이에 따른 규제체계의 개선방향을 제시하였다. 분석결과 2020년말 현재, 해양환경관리법의 적용을 받는 해양산업시설은 약 1천1백여개소에 이르는 것으로 파악되고 있다. 이들 해양산업시설로부터 배출되어 해양유입 가능성이 높은 위험유해물질은 190여종으로 추정되며, 이중 해양유입의 가능성이 가장 높은 물질은 수계로 배출되는 것으로 파악된 20여종으로 추정된다. 그러나 관련 법규정의 미비로 인하여, 배출되는 물질이 예외적 배출물질에 해당하는지 여부를 명확히 판단하기가 어려워, 현장에서의 효과적인 규제집행에 어려움을 겪고 있는 실정이다. 이에 해양환경관리법의 예외적 배출기준과 해당 물질의 종류에 대해 명확히 규정해야 하며, 예외적 배출물질을 무엇으로 할 것인지를 결정할 선정체계와 물질의 위해성 평가체계, 그리고 관련 위험유해물질의 배출정보수집 및 모니터링체계를 명확히 해야 한다.

Educational and interactive informed consent process for treatment of unruptured intracranial aneurysms

Park, Jaechan,Son, Wonsoo,Park, Ki-Su,Kang, Dong-Hun,Lee, Joomi,Oh, Chang Wan,Kwon, O-Ki,Kim, Taesun,Kim, Chang-Hyun American Association of Neurological Surgeons 2017 Journal of Neurosurgery Vol.126 No.3

<B>OBJECTIVE</B><P>For patients with unruptured intracranial aneurysms (UIAs), the information transfer that precedes informed consent needs to be in-depth and detailed, as most patients with a UIA have no symptoms, yet the risks related to treatment are relatively high. Thus, in this study an educational and interactive program was proposed for patients with UIAs to improve the informed consent process and assess the level of comprehension.</P><B>METHODS</B><P>A total of 110 patients with UIAs underwent the proposed educational and interactive informed consent (EIIC) process and were enrolled in this study. The EIIC process combines patient education using information booklets, a cartoon book, a video, an initial physician-patient interview, answering a questionnaire, a second physician-patient interview based on the questionnaire results, and finally consent. After the first physician-patient interview that provides the patient with specific information, including his or her angiographic characteristics, medical condition, and recommended treatment, the patient is requested to answer a questionnaire composed of 3 parts: demographic information, including the patient's age, sex, and years of education; 13 medical questions to assess the patient's knowledge about his or her UIA; and an evaluation of the usefulness of the educational resources. The control group consisted of 65 patients from 3 other tertiary university hospitals where the EIIC process was not used.</P><B>RESULTS</B><P>The questionnaire scores of the EIIC group ranged from 7 to 13 (mean ± SD: 11.9 ± 1.3) and were significantly higher than those for the controls (10.2 ± 1.9, p < 0.001). The better comprehension of the patients in the EIIC group was remarkable as they were significantly older than those in the control group (62.7 ± 8.3 years vs 55.9 ± 10.5 years, respectively; p < 0.001). For both the EIIC group and the control group, a Pearson correlation analysis revealed a positive correlation (r = 0.232 for the EIIC group, r = 0.603 for controls) between the years of education and the questionnaire score (p = 0.015 for the EIIC group, p < 0.001 for the controls), whereas no correlation was found between the patient age and the questionnaire score. For the EIIC group, the verbal information from the attending physician was selected by 90 patients (81.8%) as the most useful and informative educational method, while the most effective reinforcement of this verbal communication was the video (n = 86; 78.2%), information booklets (n = 16; 14.5%), the Internet (n = 7; 6.4%), and the cartoon book (n = 1; 0.9%).</P><B>CONCLUSIONS</B><P>The proposed standardized EIIC process resulted in good patient comprehension about UIAs. The verbal information from the attending physician was the most informative, and the video was the most effective reinforcement of the verbal communication. The patient level of comprehension was shown to be correlated with years of education.</P>

Internal Carotid Artery Pseudoaneurysm Secondary to Skull Base Osteomyelitis: A Case Report

Cho Hyung Joon,Son Wonsoo,Lee JiHoon,Jung Da Jung 대한청각학회 2022 Journal of Audiology & Otology Vol.26 No.1

We report a case of a pseudoaneurysm secondary to skull base osteomyelitis (SBO) in an 82-year-old female. The patient was hospitalized with an acute episode of bleeding from the right ear, which persisted despite packing placed in the ear. We suspected bleeding from the internal carotid artery (ICA) and performed angiography, which revealed a pseudoaneurysm that presumably developed secondary to invasion of the wall of the petrous segment of the right ICA, and the patient underwent emergency coil embolization. Bleeding from the ear recurred a week later, and we performed repeat angiography, followed by embolization and deployment of multiple stents at the site of the pseudoaneurysm, which controlled the bleeding. Clinicians should be mindful of a pseudoaneurysm as a rare complication of SBO, following the spread of infection to adjacent soft tissues or vessels. A pseudoaneurysm should be considered in the differential diagnosis in patients with recurrent epistaxis or bleeding from the ears in addition to cranial nerve symptoms, and this condition warrants urgent evaluation.

Calvarial slope affecting accuracy of Ghajar Guide technique for ventricular catheter placement

Park, Jaechan,Son, Wonsoo,Park, Ki-Su,Kim, Min Young,Lee, Joomi American Association of Neurological Surgeons 2016 Journal of Neurosurgery Vol.124 No.5

<B>OBJECT</B><P>The Ghajar Guide technique is used to direct a ventricular catheter at a 90° angle to the skull surface at Kocher’s point. However, the human calvaria is not completely spherical. Lateral to the sagittal midline, the calvaria slopes downward with individual variation and thereby affects the accuracy of ventricular catheter placement. Accordingly, the authors investigated the accuracy of the orthogonal catheter trajectory using radiographic simulation and examined the effect of the calvarial slope on this accuracy.</P><B>METHODS</B><P>A catheter trajectory orthogonal to the skull surface at Kocher’s point and the ideal catheter trajectory to the foramen of Monro were drawn bilaterally on coronal head images of 52 patients with hydrocephalus. The correction angle, the difference between the 2 catheter trajectories, was then measured. Meanwhile, the calvarial slope was measured around Kocher’s point by using a coronal head image. The correlation between the correction angle and factors such as the calvarial slope and bicaudate index was then assessed using a Pearson correlation analysis.</P><B>RESULTS</B><P>The ventricular catheter trajectory orthogonal to the skull at Kocher’s point in the patients with hydrocephalus led to a catheter trajectory into the ipsilateral (70.2%) or contralateral (29.8%) lateral ventricles. The correction angles ranged from −3.3° to 16.4° (mean ± SD 5.7° ± 3.7°). In 87 (83.7%) head sides, lateral deviation from the orthogonal trajectory was required to approximate the ideal trajectory, and the correction angle ranged from 2.0° to 16.4° (mean 6.7° ± 2.9°). The calvarial slope in the 104 head sides ranged from 15.6° to 32.5° (mean 24.2° ± 3.1°). Pearson correlation analysis revealed a strong positive correlation (r = 0.733) between the calvarial slope and the correction angle.</P><B>CONCLUSIONS</B><P>The accuracy of ventricular catheter placement using the Ghajar Guide technique is affected primarily by the calvarial slope around Kocher’s point. A radiographic analysis of a preoperative coronal head image can be used to estimate the accuracy of ventricular catheter placement and enable adjustment to approximate the ideal catheter trajectory.</P>