• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.5
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• pp.527-536
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• 2018

In this paper, we developed a prototype model accident management SMART-Navigation project. In order to develop a prototype model, we analyzed the status of maritime data exchange standard and procedure. We developed accident management prototype application schema, feature catalog and portrayal catalog in accordance with S-100 standard data model development procedure by collecting requirements related services and referring to related standards. In order to verify accident management prototype model, we test data set based on Gwang-yang Port. The prototype model and test data verified verification software, and it was confirmed that the designated symbol was displayed at the correct position through the S-100 simple viewer.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.05a
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• pp.205-208
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• 2002

When establishing the submarine optical fiber table between international and domestic, marine survey in advance it grasps the submarine geological features which is accurate and a depth of water condition. And the route which is safe for selecting and submarine optical fiber cable laying it is a work which secures an ease one location. If also, the PLGR the submarine of optical fiber table root the sea contamination material (rope, wire and net) it removes in advance and if the submarine of the optical fiber cable ease it does to arrive safely. And it is a work the Plough and ROV laying work hour laying work efficiency improvement and laying equipment it will be able to protect. So, This paper presents the monitoring system of ship information management and operation for marine survey and PLGR work in submarine optical fiber table construction enterprise. In order to achieve these purpose, overall serial multi-port communication modulo of configuration, realtime processing for management and operation of receiving data, realtime graph and a printout are described.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.4B
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• pp.162-169
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• 2005

Network traffic measurements show that the data traffic on packet switched networks has the self-similar features which is different from the traditional traffic models such as Poisson distribution or Markovian process model. Most of the call admission control researches have been done on the performance analysis of a single network switch. It is necessary to consider the performance analysis of the proposed admission control scheme under interconnected switch environment because the data traffic transmits through switches in networks. From the simulation results, it is shown that the call admission control scheme may not operate properly on the interconnected switch even though the scheme works well on a single switch. In this parer, we analyze the cell loss probability, utilization and self-similarity of output ports of the interconnected networks switch by using shared buffer memory management schemes and propose the new call admission control scheme considering the interconnected network switches under self-similar traffic environments.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.8
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• pp.1492-1497
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• 2017

In this paper, a design method for a CPW-fed wideband loop antenna for indoor digital TV applications is studied. The proposed loop antenna consists of a square loop and two circular sectors which connect the loop with central feed points, and the CPW feed line is inserted in the lower circular sector. The CPW feed line is designed to match with the 75 ohm port impedance for DTV applications, and the ground slots are etched in order to improve the impedance matching in the middle frequency region. The effects of the gap between the circular sectors and the location and dimension of the ground slots on the input reflection coefficient and gain characteristics are examined to obtain the optimal design parameters. The optimized antenna is fabricated on FR4 substrate, and the experiment results show that it operates in the frequency band of 463-1,280 MHz for a VSWR < 2, which assures the operation in the DTV band.

• Membrane Journal
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• v.29 no.1
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• pp.11-17
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• 2019

In the field of water treatment membranes, polymers are used together with ceramics as the most important materials. In this review, I tried to analyze the technology trends of polymer membrane materials based on commercial products. For this purpose, according to the types of water treatment membranes such as MF (Microfiltration), UF (Ultrafiltration) and NF (Nanofiltration), the trends of polymer membrane products were investigated by countries, materials, and companies. Through this, we were able to classify the types of materials that are mainly used for each type of membrane, and at the same time, identify the companies that are dominant in the market, and analyze which materials constitute the product portfolio. Based on these results, we have presented the characteristics of the material market according to each type of membrane, and proposed a technology development strategy to enter each market based on these characteristics.

• Journal of The Geomorphological Association of Korea
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• v.19 no.3
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• pp.123-134
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• 2012

This work is to describe the geomorphological landscapes of of Dongcheon-gugok in Korea, and attempts to develop a basic data for traditional natural heritage. Dongcheon-gugok is a union of natural lanscape and human mind-activity. Therefore the study of natural landscape, which consists of geomorphological landscapes, provides a basic data for the use and conservation of traditional natural heritage. Dongcheon-gugok in Korea is almost distributed in the valley of mountainous areas of Taeback and Soback Mountain Ranges. The bedrocks of the areas of Dongcheon-gugok are almost granitic rocks and sedimentary rocks. The landscapes of Dongcheon-gugok is characterized by narrow meandering valley, so Gugok means nine-bended river. The elements of the geomorphological features is a broad flat rock with sheeting joints, joint-block seperated large blocks or tor, steep slope and rocky cliffs, pool, ripple, large or small scale waterfall, pot-hole, etc.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.12
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• pp.129-135
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• 2021

Injection molding is a manufacturing method of melting the polymer resin and injecting it into a mold to molding it into the desired form. Due to the short molding time and outstanding formability, complex products can be shaped with high precision and it is the most widely used polymer molding method. However, there may be areas that are not filled depending on the location of the injection gate where polymer resin is injected. Formability is determined by deformation and surface precision due to the impact of residual stress after molding. Hence, choosing the location of the injection gate is very important and molding analysis of injection molding is essential to reduce the cost of the mold. This study evaluated the injection formability based on the location of the injection gate of the vertical machining center ATC tool port using injection molding analysis and the results were compared and analyzed. Injection molding analysis was conducted on filling, packing, and deformation according to the location of the gate of the ATC tool port. From each injection gate location, filling time, pressure, and maximum deformation were compared. At gate 2, conditions of molding time and the location of the gate were far superior in production and quality. Gate 2 produced the smallest deformation of 0.779mm with the best quality.

• The Journal of the Convergence on Culture Technology
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• v.9 no.3
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• pp.701-706
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• 2023

The Korean government and industry have presented a roadmap for the commercialization of UAM services and are promoting it in earnest. In order to introduce full-scale UAM services, there are various issues to be solved, such as the development of high-performance aircraft, the design of network bases and corridors, the optimization of operation management, and the establishment of related laws and systems. In this study, in terms of optimizing operation management, we will examine research trends by field, focusing on Korea, and derive research topics that need to be solved in the future. Korean researchers have suggested that research is centered on UAM service usage fees, usage intentions and acceptance models, and vertiport location selection, but operational optimization studies such as service order acceptance, aircraft repositioning, and battery charging and maintenance scheduling are needed in the future.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.276-277
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• 2012

플라즈마 아킹은 PECVD, 플라즈마 식각 그리고 토카막과 같은 플라즈마를 이용하는 여러 공정과 연구 분야에서 문제가 되어왔다. 하지만, 문제의 중요성과 다르게 아킹에 대한 본질적인 연구는 아직 미비한 상태이다. 플라즈마 아킹은 집단전자방출(collective electron emission)에 의한 스파크 방전(spark discharge) 현상이다. 집단전자방출은 전계방출(field emission)이나 플라즈마와 쉬스를 두고 인접한 표면위에서의 유전분극(dielec emission)에 의해 발생한다. 우리는 CCP 플라즈마를 이용해 micro-arcing(MA)을 일으키고 랑뮈르 프로브를 이용해 MA 동안의 플로팅 포텐셜의 변화를 측정한다. MA시 PM-tube를 이용해 광량의 변화를 측정하고 플로팅 포텐셜을 fast-imaging과 동기화 시켜 MA 발생 메커니즘을 유추한다. 우리는 $30{\times}20$ cm 크기의 사각 전극을 위 아래로 가진 챔버에서 Ar 가스를 RF (13.56 MHz) 파워를 이용해 방전시켰다. 방전 전압과 전류는 파워 전극 앞단에서 High voltage probe (Tektronix P6015A)와 Current probe (TCPA300 + TCP312)를 이용해 측정했다. 플라즈마 아킹시 변하는 플라즈마 플로팅 포텐셜은 챔버 중앙에 위치한 랑뮈프 프로브에 의해 측정되고 챔버 옆의 뷰포트 앞에 위치한 PM-tube를 이용해 아킹시 변하는 광량을 측정하고 Intensified CCD를 이용해 fast-imaging을 한다. 또한 CCD 앞에 band pass filter를 부착하여 MA의 발생 메커니즘을 유추한다. RF 방전에서의 플라즈마 아킹은 아킹시 플로팅 포텐셜의 변화에 의해 크게 세부분으로 나눌 수 있다. 아킹 발생과 동시에 급격히 감소하는 감소부분(약 2 us) 그리고 감소한 포텐셜이 유지되는 유지부분(약 0~10 ms) 그리고 감소했던 포텐셜이 서서히 원래 상태로 회복되는 회복부분(약 100 us)이다. 아킹 초기시 방출된 집단 전자들은 쉬스를 단락시키게 되고 이로 인해 플로팅 포텐셜은 급격히 감소하게 된다. 이렇게 감소한 플로팅 포텐셜은 아킹 스트리머가 유지되는 한 계속 감소한 상태를 유지하게 된다. 그리고 플라즈마를 섭동했던 집단전자방출이 중단되면 플라즈마는 섭동전의 원래 상태로 회복된다. 플라즈마 아킹 발생시 생성되는 순간적으로 많은 전자들을 국소적으로 생성하게 되고 이 전자들에 의해 광량이 순간적으로 증가하게 된다. PM-tube (750.4 nm)에 의해 측정된 아킹시 광량은 정상방전 상태의 두배 가량이 된다. 그리고 이 순간적으로 증가된 광량은 시간이 지남에 따라 감소하게 되고 정상방전 일때의 광량이 된다. 광량이 증가한 후 정상방전상태의 광량에 이르는 부분은 플로팅 포텐셜이 감소한 상태에서 유지되는 부분과 일치하고 이는 플로팅 포텐셜의 유지부분동안 집단전자방출이 있다는 간접적인 증거가 된다. 그리고 정상 방전 상태 일때의 광량이 되면 집단전자방출이 중단되었다는 것이므로 그 시점부터 플로팅 포텐셜은 정산 방전상태 일때의 포텐셜로 복구되기 시작한다. 이처럼 PM-tube를 이용한 아킹 광량 측정은 아킹 스트리머를 간접적으로 측정하게 하고 집단전자방출을 이용해 아킹 시의 플로팅 포텐셜의 변화를 설명하게 해 준다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.5
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• pp.1-12
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• 2015

Length and the number of tunnels has increased 10% annually. Tunnel construction has positive effect in nature and driving condition. However, the structure of tunnels lead to a greater probability of major accidents. For this reason, tunnel is focusing its attention on the rapid incident handling and disaster management to build a tunnel management system in recently. In this study, tunnel management system adequacy analyzed in terms of operational safety using IPA and AHP analysis. IPA analysis results using the portfolio chart, incident management factors has a large gap between important and satisfaction. Disaster management is analyzed high ranking in priority. However, incident management factors are derived first priority in AHP analysis. This study determined that the results are meaningful to practitioners in the field is determined. In addition, practitioners comments should be reflected primarily for tunnel operational safely.