• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.12
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• pp.1395-1401
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• 2014

In an effort to develop and implement an inertial balance with high performance, the response characteristics of a load cell, which are some of the critical parameters for optimal system design, were evaluated using a sample object of approximately 100 g under microgravity conditions. To this end, a 15-m drop-tower was used to produce microgravity conditions, and the response characteristics of the load cell were investigated in terms of the variations in the magnitude of the deceleration of the sample object, noting that the mass of a living animal should be determined in microgravity. An analysis of the ratio of the inertial forces clearly demonstrated that the average velocity of a load cell plate should be higher than 0.5 m/s to meet the design requirements.

• The Journal of the Convergence on Culture Technology
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• v.1 no.2
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• pp.1-19
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• 2015

The history of modernization of Korea is divided into two folds of the colonial era in the 20's and the economic development era in the 60's. Most of the spaces built in the process of modernization were public spaces developed by the drive of the government. These spaces of modernization are functionality-oriented public places of production and at the same time, and they are the spaces of national power to symbolize the identity of national authorities. Along with changes in the society, modern spaces were reduced down to monument buildings without functionality and this requires new definition to renew the identity of modern spaces. Small stations, power plants, mines, warehouses, abandoned factories, and etc... the study has paid attention to the process of changing thought, one of the main characteristics of modernization, the relations of modern concepts projected in the spaces, framework of modern society, and placeness in the process of framework building and relations of people in the spaces with video records on the process of rebuilding new identity of modern spaces and memories of the spaces. The relations of modern spaces and memory were explored in < Seoul Station > while the relations between modern spaces and records and place identity were explored in < Onyang Folk Museum > and < Okpo Shipyard > respectively. In the relations between space identity and memory in each space, the ironic relations of power in modern spaces (placeness) and personal narrative (memories) were explored with oral narrative and video footage.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.33-37
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• 2006

Since 1993, the civil aviation community through RTCA (Radio Technical Commission for Aeronautics) and the ICAO (International Civil Air Navigation Organization) have been working on the definition of GNSS augmentation systems that will provide improved levels of accuracy and integrity. These augmentation systems have been classified into three distinct groups: Aircraft Based Augmentation Systems (ABAS), Space Based Augmentation Systems (SBAS) and Ground Based Augmentation Systems (GBAS). The last one is an implemented system to support Air Navigation in CAT-I approaching operation. It consists of three primary subsystems: the GNSS Satellite subsystem that produces the ranging signals and navigation messages; the GBAS ground subsystem, which uses two or more GNSS receivers. It collects pseudo ranges for all GNSS satellites in view and computes and broadcasts differential corrections and integrity-related information; the Aircraft subsystem. Within the area of coverage of the ground station, aircraft subsystems may use the broadcast corrections to compute their own measurements in line with the differential principle. After selection of the desired FAS for the landing runway, the differentially corrected position is used to generate navigation guidance signals. Those are lateral and vertical deviations as well as distance to the threshold crossing point of the selected FAS and integrity flags. The Department of Applied Science in Naples has create for its study a virtual GBAS Ground station. Starting from three GPS double frequency receivers, we collect data of 24h measures session and in post processing we generate the GC (GBAS Correction). For this goal we use the software Pegasus V4.1 developed from EUROCONTROL. Generating the GC we have the possibility to study and monitor GBAS performance and integrity starting from a virtual functional architecture. The latter allows us to collect data without the necessity to found us authorization for the access to restricted area in airport where there is one GBAS installation.

• The Journal of the Convergence on Culture Technology
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• v.9 no.3
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• pp.579-585
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• 2023

The purpose of this study is to explore keywords within stalking-related news articles according to political orientation through the text network analysis, and then to examine the implicit intentions. Selecting total 1,607 articles including 824 articles of the conservative press(The Chosun Ilbo, The Joongang Ilbo) and 783 articles of the progressive press(The Hankyoreh, The Kyunghyang Shinmun) reported from January 1, 2018 to December 31, 2022, this study explored the aspect of topic category drawn through the topic modeling technique based on LDA(Latent Dirichlet Allocation). In the results of this study, the common topics of the conservative and progressive press were improvement of the perception of gender-based violence, personal protection & intensity of punishment, and disclosure of stalkers' personal information. Regarding the topics differently shown in those two press, the conservative press showed stalkers' harmful act, and outline of 'murder case at Sindang Station' while the progressive press showed request for aggravated punishment on the 'murder case at Sindang Station', and eradication of sexual exploitation crime (in cyber space). The results of this study imply that there are changes in the type of reporting according to ideological opinions about stalking in news articles.

• International Journal of Ocean System Engineering
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• v.1 no.4
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• pp.198-204
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• 2011

Recently, several problems have occurred in the space, infra-structure, and facility of the contiguity of existing harbors due to the trend of enlarged container vessels. In this regard, the Mobile Harbor has been proposed conceptually in this study as an effective solution for these problems. The concept is that of a transfer loader that transfers containers from a large container ship to the harbor on land, and is a catamaran type floating barge. The catamaran-type vessel is well known for its advantage in maneuverability, resistance, and effectiveness for working on board. For the safe and effective operation of the two floating bodies (a container ship and the mobile harbor in the near sea detached from the quay), robot arms, novel crane systems, and pneumatic fenders are specially devised with an additional mooring facility or DP (dynamic positioning) system. In this study, this concept is to be verified through comparison and simulation studies under various environmental conditions. It is shown that the proposed concept is in general feasible but there are several areas for further investigation and improvement.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.11a
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• pp.7-10
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• 2011

최근 국제우주정거장에서 화재안전에 관한 중요성의 인식으로 화재의 감지/소화의 메커니즘을 구체적으로 이해하기 위한 다양한 연구들이 시도되고 있다. 본 연구에서는 국제우주정거장에서 각종 실험과 연구를 진행하는 가압모듈을 대상으로 환기, 연기거동 및 감지에 관한 수치모델링을 수행하였다. 수치모델링은 NIST에서 개발된 FDS (Fire Dynamic Simulator)가 사용되었다. 국제우주정거장 내부는 마이크로중력환경으로 부력이 존재하지 않아 화재 발생 시 화염 및 연기거동은 지상에서의 현상들과 큰 차이를 보이게 된다. 따라서 현재 가압모듈에서 적용되고 있는 환기조건의 변화에 따른 연기거동 및 감지특성에 대한 연구는 향후 국내의 국제 우주정거장 실험 참여를 위한 기초적인 정보를 제공할 것으로 기대된다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.1
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• pp.90-97
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• 2014

In this paper, we have designed the antenna for Korea SAT-5 Satellite Communication which can use Ka band in the earth station. The antenna structure consist of the the dual-offset gregorian reflector that has high gain and efficiency, the corrugated horn that has symmetric radiation patterns and low side lobe levels, the iris polarizer that make circular polarization and the OrthoMode Transducer that separate transmitting and receiving signals. The designed antenna gain is more than 45.7dBi in Tx-band which use LHCP and 42.0dBi in Rx-band which use RHCP. The co-polarized and cross-polarized radiation pattern comply with ITU-R S.580-6 and S.731-1 that are recommended by International Telecommunication Union in the geostationary satellite. The Axial ratio is less than 1.0dB in Tx-band and 1.5dB in Rx-band that meet MIL-STD-188-164A.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.267-268
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• 2002

Microbeam is a new avenue of radiation research especially in radiation biology and radiation protection. Selective irradiation of an ionizing particle to a targeted cell organelle may disclose such mechanisms as signal transaction among cell organelles and cell-to-cell communication in the processes toward an endpoint observed. Bystander effect, existence of which is clearly evidenced by application of the particle microbeam to biological experiments, suggests potential underestimation in the conventional risk estimation at low particle fluence rates, such as environment of space radiations in ISS (International Space Station). To promote these studies we started the construction of our microbeam facility (named as SPICE) to our HVEE Tandem accelerator (3.4 MeV proton and 5.1 MeV $^4$He$\^$2+/). For our primary goal, "irradiation of single particle to cell organelle within a position resolution of 2 micrometer in a reasonable irradiation time", special features are considered. Usage of a triplet Q magnet for focussing the beam to submicron of size is an outstanding feature compared to facilities of other institutes. Followings are other features: precise position control of cell dish holder, design of the cell dish, data acquisition of microscopic image of a cell organelle (cell nucleus) and data processing, a reliable particle detection, soft and hard wares to integrate all these related data, to control and irradiate exactly determined number of particles to a targeted spot.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.9
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• pp.760-770
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• 2012

In order to provide precision approach service based on GBAS, air navigation service providers should validate the GBAS system performance against international standard requirements and receive approval. The GBAS manufacturer should define integrity threat, analyze the integrity monitors and evaluate performance of the implemented monitors to verify integrity performance which is critical to the aircraft safety. This paper describes a statistical test result to evaluate performance of the code carrier divergence monitors implemented in KARI Integrity Monitor System software. The paper introduces analysis and test procedure which is developed for the performance evaluation and describes the analysis, the test scenario generation and the test results. The results show that the implemented monitors can detect the expected minimum detectable errors with satisfying the probability of missed detection requirements.

• Smart Structures and Systems
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• v.19 no.1
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• pp.1-10
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• 2017

The operation of subway trains induces secondary structure-borne vibrations in the nearby underground spaces. The vibration, along with the associated noise, can cause annoyance and adverse physical, physiological, and psychological effects on humans in dense urban environments. Traditional tethered instruments restrict the rapid measurement and assessment on such vibration effect. This paper presents a novel approach for Wireless Smart Sensor (WSS)-based autonomous evaluation system for the subway train-induced vibrations. The system was implemented on a MEMSIC's Imote2 platform, using a SHM-H high-sensitivity accelerometer board stacked on top. A new embedded application VibrationLevelCalculation, which determines the International Organization for Standardization defined weighted acceleration level, was added into the Illinois Structural Health Monitoring Project Service Toolsuite. The system was verified in a large underground space, where a nearby subway station is a good source of ground excitation caused by the running subway trains. Using an on-board processor, each sensor calculated the distribution of vibration levels within the testing zone, and sent the distribution of vibration level by radio to display it on the central server. Also, the raw time-histories and frequency spectrum were retrieved from the WSS leaf nodes. Subsequently, spectral vibration levels in the one-third octave band, characterizing the vibrating influence of different frequency components on human bodies, was also calculated from each sensor node. Experimental validation demonstrates that the proposed system is efficient for autonomously evaluating the subway train-induced ambient vibration of underground spaces, and the system holds the potential of greatly reducing the laboring of dynamic field testing.