• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.8
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• pp.1427-1433
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• 2008

There is SARLM scheme for dynamic adaptation to network congestion status which arises from multicast applications. However, in this scheme, when congestion occurs in a local, the waste of available bandwidth occurs in non-congestion local because of reducing of transmission rate in congestion local. In this paper, we propose a hierarchical multicast for dynamic adaptation to network congestion. In proposed scheme, we select a representative in each local. while congestion status. It receives packet from multicast sender and hierarchically transmits packet to the representative in congestion status by unicast for preventing decrease of transmission rate and the representative in congestion local transmits packet to the receivers in local by multicast. In experimental results, it was known that the proposed scheme could improve transmission rate of receivers in congestion status and more efficiently used available bandwidth.

• Korean Journal of Remote Sensing
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• v.13 no.1
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• pp.31-46
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• 1997

In recent years, as remotly-sensed image processing technologies have been improved and spread widely in the application areas, many new requirements for the image processing technologies have arisen. However, it is difficult and costly to access remotely-sensed image processing systems. Moreover, these systems have thier own processing facilities which are not easily accessible for general users. In this paper, those problems are challenged by adopting Internet as a universal information network for accessing remotly-sensed image DBMS and by allowing users to work remotely on the image processing. A remotly-sensed image processing system which can be accessed via Internet was designed and implemented. This system can be used to manipulate images over remote DBMS. The Illustra object-oriented relational DBMS with CGI(Common Gateway Interface) web interface was used in this project. The client consists of a WWW(World Wide Web) Netscap$e^{TM}$ browser, and the server consists of HTTPD(Web daemon), Illustra DBMS and Java modules in order to process the image being displayed. The developed system was tested on LAN environment and the service response time met the requirements.

• Korean Journal of Remote Sensing
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• v.23 no.4
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• pp.247-256
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• 2007

In this paper we introduced GB-SAR focusing algorithms for image formation and suggested an optimized solution. We compared the characteristics, advantages, and limitations of the Deramp-FFT (DF) algorithm and the Range-Doppler (RD) algorithm in terms of their image formation principles, memory usage and processing time. We found that DF algorithm is efficient in memory and processing time but can not focus the near range. The RD algorithm can focus the entire range but, considering the refinement on the rail length, it has much redundancy in memory and processing time. In conclusion, we optimized the GB-SAR focusing by using the DF algorithm for a far-range case and the RD algorithm for a near-range case separately.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.83-83
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• 2015

최근 수자원 이용량의 증가 및 수자원 공급의 부족에 따라 대안으로 제시되고 있는 지하수 이용은 매년 크게 증가하고 있다. 내륙 지역의 지하수 개발 시와 비교할 때 해안 지역의 지하수 개발에는 해수침투 현상에 대하여 추가적 고려가 필요하다. 알려진 바와 같이 해안 지역의 과잉 양수와 해수면 상승 으로 해수침투가 더욱 깊이 침투하고 있는 실정이다. 이에 대해 정략적인 해수 침투길이 산정과 더불어 해수침투를 허용가능한 범위 내로 제한 시키는 지하수 개발이 필요하다. 해수침투 저감 공법에는 저투수차수벽 설치, 담수주입공법, 해수양수공법으로 크게 3가지로 구분할 수 있다. 저투수차수벽의 해수침투 저감 효율은 크지만 비용이 비싸다는 단점으로 본 연구에서 제외시켰다. 담수주입공법은 대수층에 담수를 주입하여 해수침투를 저감시키는 공법으로 인근에 양질의 수원을 필요로 하는 단점이 있다. 해수양수는 해안가에 양수정을 설치하여 해수침투를 저감시키지만 양수정에서의 담수가 혼합되어 담수낭비가 생기는 단점이 있다. 본 연구에서는 해안지하수의 해수침투를 저감시키기 위한 방법중 담수주입과 해수양수공법의 효율을 검증하고 각각 공법의 장단점을 비교하였다. 지하수 경계면 모델을 이용하여 각각의 수리수문 변수들이 미치는 영향과 해수침투 정도를 사례별로 연구하였다. 담수주입공법의 경우 담수주입량 많을수록 해수침투가 저감되는 경향이 있지만 최적의 담수주입량을 찾는데 목적이 있다. 해수양수공법에는 해수양수량이 증가하고 해수양수정의 위치가 해안선에 접할수록 해수침투 저감 효과가 있었다. 담수주입공법과 해수양수공법을 해수침투 저감을 위해 해안가에 적용할 경우 해당 지역의 특성을 면밀히 분석하여 적용해야 효과를 볼 수 있다.

• Journal of Convergence for Information Technology
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• v.9 no.10
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• pp.48-55
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• 2019

This study argued problems and improvement of export support system for SMEs in the uncertain world global trade environment with G2(US-China) risk. In SMEs export support system, The authorities needs stronger control tower to promote consistent export support policies. There is also another problem of repetitious work that export support system has been operated by individual project. In order to overcome these problems, first, the authorities set clearly organization to control various export support policies. Second, export support system needs the efficient operation based on long term road map. Third, the authorities defines clear roles and responsibilities of supporting units, and enhances cooperation between the different organizations. Finally, the system should arrange performance evaluation index and feedback system to build the desirable export support system.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.285-285
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• 2015

댐 및 저수지 시설물은 노후화나 안전성 미확보로 인한 파손 또는 붕괴 발생 시 하류부에 막대한 인명과 재산피해 등 치명적인 결과를 초래하게 된다. 이러한 대형 안전사고를 예방하고자 시설물의 안전관리에 관한 특별법에서는 댐 시설물을 규모별로 1, 2종 시설물로 구분하고, 이에 대해 주기적으로 안전점검 및 정밀안전진단을 실시하도록 제도화하는 한편 진단 결과에 따라 보수 보강 등의 안전조치를 의무화하고 있다. 구조물 결함에 따른 보수 보강은 보수재료와 공법 선정시 공법의 적용성, 구조적 안전성, 경제성 등을 종합적으로 검토하여 결정하여야 한다. 손상 부위에 대한 보수 보강은 제한된 예산과 인력을 효율적으로 투자하기 위해 보수재료 및 공법의 선정 뿐만 아니라 보수 보강이 이루어져야 하는 부재에 대한 우선순위를 산정하는 것이 최우선적으로 선행되어야 한다. 안전점검 및 정밀안전진단 세부지침에서는 보수 보강 대책 마련 시안전점검 및 정밀안전진단 결과를 기초로 하여 적정 재료 및 공법을 선정하고, 보수 보강의 수준 및 우선순위를 결정하도록 명시되어 있다. 하지만 우선순위 결정에 대한 가이드라인이 부재하여 불필요한 시공과 비효율적인 예산 투입으로 인해 국가예산의 낭비되고 시설물의 안전까지 위협받게 되는 경우가 발생하고 있다. 따라서 본 연구에서는 시설물의 상태에 따른 적절한 보수 보강 필요성을 판단하고 보수 보강 수준 및 우선순위를 결정하기 위한 방법론을 개발하였다. 댐 시설물에 대한 안전점검 및 정밀안전진단의 종합평가는 평가대상 개별시설에 대하여 상태 평가 및 안전성 평가를 실시한 후 그 결과에 의해 산출된 상태평가지수와 안전성평가지수를 비교하여 평가단계별로 그 결과를 취합하여 종합평가를 실시하고 있다. 따라서 상태평가에 의해 산정된 종합평가 결과를 이용하여 개별 부재의 상태평가값 산정을 위해 하부 단계의 가중치 및 평가 지수 역산하고, 재산정된 가중치 및 평가지수를 이용하여 각 부재에 대한 보수 보강 우선순위를 산정하고자 하였다. 개발된 방법론은 점검 진단 책임기술자 및 시설물 관리주체 담당자가 댐 시설물의 개별부재에 대한 보수 보강 실시 여부를 판정할 수 있는 기준으로, 보수 보강에 대한 정책 결정시 경제성을 고려한 신뢰도 있는 기준으로 활용될 수 있을 것으로 기대된다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.784-788
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• 2009

In recent years, the driver needs the convenience of their vehicles and that there is an increasing requirement. Many researches have been mainly focused on MOST Networks to provide quality of multimedia service. The MOST network to support different bandwidth(MOST 25, MOST 50, MOST 150) should consist of a heterogeneous network. So the networks to used different protocols required gateway for receive and transmit information. The method to used gateway has problems occured loss of a packet by a lot of delay. Therefore in this paper, we propose a MOST GATEWAY system for organically connected to the network MOST150 and MOST 25. After analyzing the performance of the existing scheduling algorithm, we will present an improvement scheme of the efficiency and scalability.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.5
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• pp.631-636
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• 2019

Over the last decade, many researchers have investigated a number of vision-based construction object detection algorithms for the purpose of construction site monitoring. However, previous methods require the ground truth labeling, which is a process of manually marking types and locations of target objects from training image data, and thus a large amount of time and effort is being wasted. To address this drawback, this paper proposes a vision-based construction object detection framework that employs an active learning technique while reducing manual labeling efforts. For the validation, the research team performed experiments using an open construction benchmark dataset. The results showed that the method was able to successfully detect construction objects that have various visual characteristics, and also indicated that it is possible to develop the high performance of an object detection model using smaller amount of training data and less iterative training steps compared to the previous approaches. The findings of this study can be used to reduce the manual labeling processes and minimize the time and costs required to build a training database.

• Journal of the Korea Society for Simulation
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• v.25 no.4
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• pp.65-75
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• 2016

Unused spare parts of military equipments which have been kept in the warehouse for a long term have been recognized as wasting of defense budget which also decreased people's confidence in the field of national defence. It is known that overstock is caused by information distortion and bullwhip effect from downstream to upstream in the logistic support as is like business cases. After upgrading the logistic information system, it is possible for Army Logistics Command(ALC) to know demand information of end-user which is the key factor to reduce bullwhip effect. However, inventory is still overstocked and stock-out at the same time. Previous studies have not accounted for these phenomenons and have mainly focused on forecasting inventory level instead of budgetary process(budget period, PROLT, ASL/N-ASL). Thus, this study focuses on the information distortion, overstock and stock-out which caused by budgetary process in the logistic support with system dynamics and simulation.

• Journal of the Korea Society of Computer and Information
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• v.15 no.1
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• pp.51-59
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• 2010

Apartment complex, buildings, markets and department stores have inner parking lots which can accept many cars but drivers waste lots of times to find the empty parking spaces in crowding parking lots. In this paper, we proposed the inner parking information support system based on microprocessor which can decrease roaming times to find vacant parking spot in confusing parking lots through notice monitor and provide SMS to make it easy to find parked place. Proposed system consist with RFID system for detecting access of cars, microprocessor system for processing data of checking existence of cars on parking spots and communicating with server, and server system which processes information of cars' in and out, guides empty parking spots and parked location to drivers. Suggested system is realized by handmade model parking lot size of 8 cars, and we confirmed practicality by providing information using parking notice monitor and single message service.