건설신기술지정제도의 평가기준에 관한 연구

서용철,현창택 대한건축학회 1998 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.18 No.2

Building DSMs generation integrating Three Line Scanner (TLS) and LiDAR

서용철,Masafumi Nakagawa 대한원격탐사학회 2005 大韓遠隔探査學會誌 Vol.21 No.3

Aerodynamic losses for squealer tip with different winglets

서용철,이상우 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.2

Aerodynamic loss measurements and flow visualizations have been conducted for a squealer tip with different winglets. The present results for seven winglets indicate that winglet coverage along the pressure side has a negative effect in the loss reduction, whereas winglet coverage along the suction side has a positive effect. Winglet coverage along both sides performs better than that along the pressure side but worse than that along the suction side. The upstream half of the suction-side winglet plays a crucial role in the loss reduction. Thus, this portion needs to be included in the winglet for better aerodynamic performance. The pressure-side winglet brings additional flow disturbances similar to the ones existing over the plane tip back to the tip gap flow over the squealer tip. For the suction-side winglet, however, the tip gap flow is separated from the casing in a wide range between the leading edge and mid-chord.

Tip gap flow and aerodynamic loss generation in a turbine cascade equipped with suction-side winglets

서용철,이상우 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.3

The tip gap flow and aerodynamic loss generation over a plane tip equipped with a “constant-width suction-side” (CWSS) winglet and a “varying-width suction-side” (VWSS) winglet have been investigated in a turbine cascade. For a fixed tip gap of h/c = 2.0%, three different winglet widths of w/p = 5.28, 10.55, and 15.83% are tested for the CWSS winglet. The VWSS winglet is designed based on flow visualization and has almost the same winglet area as the CWSS winglet of w/p = 15.83%. In general, the suction-side winglets have a role to increase aerodynamic loss in the tip leakage vortex region but reduce aerodynamic loss in the passage vortex region. For the CWSS winglet, the total-pressure loss coefficient mass-averaged all over the measurement plane has no appreciable changes with increasing w/p from 0.0 to 10.55%, but tends to decrease with further increment of w/p. The VWSS winglet performs better in reducing aerodynamic loss in the passage vortex region than the CWSS winglet of w/p = 15.83% but leads to a little bit higher aerodynamic loss in the tip leakage vortex region. The aerodynamic loss reduction by the VWSS winglet is 7.4% in comparison with the plane tip without winglet, and is about 60% lower than that by the widest CWSS winglet.

Development of an INS Integrated Autonomous Positioning System for Assisting Effective Fire-fighting Activity

서용철 대한토목학회 2004 KSCE JOURNAL OF CIVIL ENGINEERING Vol.8 No.5

This paper describes the development of an INS (Inertial Navigation System) integrated autonomous positioning system, which can monitor and track the firefighter's position to assist a variety of fire-fighting activity and rescue services. By integrating an INS to the positioning system, it is also possible to obtain information of firefighter's position and physical state of posture (e.g. standing, collapsed or crouching), including velocity, without using external signal sources, since the INS consists of a highly accurate three-axis gyro sensor and a three-axis accelerometer. This complete system consists largely of three parts; the heart of the system, i.e., the INS integrated autonomous positioning system, a three - dimensional display system for displaying the firefighter's position and posture on a three - dimensional digital map, and a communication system using the laryngeal microphone to communicate with members outside the site of accident. Consequently, this research would obviously contribute to more efficient rescue activities as well as to the safety of the firefighters. Besides, we also summarize the overall system requirements and describe the architecture of hardware and software used in the prototype system in detail, and this paper presents results from field tests conducted at Tokyo University demonstrating its viability and utility.

An Adjustment for a Regional Incongruity in Global Land Cover Map: case of Korea

서용철,박윤영,한경수,염종민 대한원격탐사학회 2006 大韓遠隔探査學會誌 Vol.22 No.3

우리나라와 일본의 국가 GIS 추진전략 및 유비쿼터스 정책 비교분석

서용철(Suh Yong Cheol),사공호상(Sakong Ho Sang),이영주(Lee Young Joo) 대한공간정보학회 2008 대한공간정보학회지 Vol.16 No.2

오늘날 정보화는 디지털 환경에서 유비쿼터스 정보환경으로 발전하고 있다. 이러한 정보환경의 변화에 효과적으로 대응하기 위해서 정부는 유비쿼터스 기술을 이용하여 국가발전을 추구하고자 u-Korea 정책을 추진하고 있다. 한편, 국가의 공간정보화의 기틀인 국가GIS 역시 유비쿼터스 환경으로의 발전을 모색하고 있다. 그러나 아직까지 유비쿼터스 정보환경에 대한 뚜렷한 변화와 관련기술의 실용화는 나타나지 않고 있는 실정이다. 본 연구는 ‘유비쿼터스’라는 정보환경의 변화에 직면한 국가GIS 정책 방향을 모색하기 위해 우리나라와 일본의 유비쿼터스 정책 및 국가GIS 추진전략을 상호 비교하여 각 분야별 시사점을 도출하였다. Informatization today has been developed in a ubiquitous environment unifying real and virtual space from digital space. To reflect on this trend, the government has promoted the u-Korea Project, which is a national strategy based on ubiquitous technology. With this national informatization policy, ‘The Creation of the Infrastructure for Realization of Ubiquitous Country’ for establishing a ubiquitous world is presented in the 3rd National Geographic Information System (NGIS) Master Plan, which manages national spatial information. However, we have not yet discovered distinct change for ubiquitous environments and practical technologies. The purpose of the study is to explain the current status of Ubiquitous policies and National GIS policies as a representative national information strategies directed toward the ubiquitous society by comparing Korea and Japan, and then develops improved strategies for the future.

지리정보시스템을 위한 고속 측지계 변환 모델 연구

서용철 ( Yong Cheol Suh ) 한국지리정보학회 2004 한국지리정보학회지 Vol.7 No.3

This research focuses on the development of a fast datum transformation model to be used in GIS that utilizes real-time data transformation. Instance, when a GIS data constructed according to a datum is conformed to another datum, instead of transforming the axes of the original data, the data is transformed right before the results are reflected on the monitor. In this research, the prospects of calculating transformation parameters for every grid cells on the area based on two-dimensional conformal transformation model in order to decrease real-time datum transformation time while maintaining a high accuracy has been investigated. Research results showed that for a fixed area, the accuracies of the two-dimensional conformal transformation and the three-dimensional datum transformation, which requires more computing time, were almost equal and fast transformation speed, high accuracy real-time datum transformation is made feasible by implementing the grid-divided two-dimensional conformal transformation model.

GIS 데이터 취득을 위한 위성측위 환경의 실험적 평가

서용철 ( Seo Yong Cheol ) 한국지리정보학회 2003 한국지리정보학회지 Vol.6 No.4

Satellite-based positioning system such as global positioning system(GPS) has played a major role in data capture technology for constructing GIS database. Recent advances in satellite-based positioning technology have made the task of precisely locating features fast, easy, and inexpensive, and determined their current latitude and longitude. However, there are still situations where satellite-based positioning service will not provide users with desired precision such as in urban environments, that is, the only severe handicap still hampering satellite-based positioning is the well-known problem of restricted satellite visibilities. As the majority of the creation and updating of road and street network are carried out in urban environments, the obstruction problem considerably impedes the wider application of satellite-based positioning. This paper presents the current GPS-based positioning environment for GIS data acquisition in urban areas. A field experiment with measurement vehicle has been performed under varying operational conditions and areas where shading of satellite signal is encountered due to buildings and overpasses with measurement vehicle in order to evaluate the availability of existing GPS-based positioning. We found that the current GPS-base positioning system we used in the study was insufficient for a precise GIS data acquisition. this research would make a contribution for the development of base data to supplementary technology, which can complement the existing GPS-based positioning.

실내 환경에서의 3차원 공간데이터 취득을 위한 IMU, Laser Scanner, CCD 센서의 통합

서용철 ( Yong Cheol Suh ),장정정언 ( Masahiko Nagai ) 한국지리정보학회 2007 한국지리정보학회지 Vol.10 No.1

3D data are in great demand for pedestrian navigation recently. For pedestrian navigation, we needs to reconstruct 3D model in detail from people`s eye. In order to present spatial features in detail for pedestrian navigation, it is indispensable to develop 3D model not only in outdoor environment but also in indoor environment such as underground shopping complex. However, it is very difficult to acquire 3D data efficiently by mobile mapping without GPS. In this research, 3D shape was acquired by Laser scanner, and texture by CCD(Charge Coupled Device) sensor. Continuous changes position and attitude of sensors were measured by IMU(Inertial Measurement Unit). Moreover, IMU was corrected by relative orientation of CCD images without GPS(Global Positioning System). In conclusion, Reliable, quick, and handy method for acquiring 3D data for indoor environment is proposed by a combination of a digital camera and a laser scanner with IMU.