• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.264-264
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• 2017

국외의 상수도 원격검침 시스템 내 데이터 전송방식은 도시 규모, 계량기의 밀도, 전력공급 여부 및 통신망의 설치 여부 등을 종합적으로 고려하여 결정되었다. 대부분의 스마트워터미터 제조업체들은 계량기의 부호기가 공급하는 판독 내용(데이터)을 전송할 검침단말기와 근거리 통신망(neighborhood area network)을 연계하여 개발 및 판매하였으며, 자체 소유 통신 프로토콜을 사용하여 라디오 주파수(RF) 통신 기술을 사용하고 있다. 광역통신망(wide area network)의 경우, 노드(말단의 계량기 및 센서)들과 이에 연결된 통신망 들을 포함한 네트웍의 배열이나 구성이 스타(star), 메쉬(mesh), 버스(bus), 나무(tree) 등의 형태로 통신망이 구성되어 있으나, 스타와 메쉬형 통신망 구성형태가 가장 널리 활용되는 것으로 조사되었다. 시스템 통합운영관리 업체들인 IBM, Oracle, Itron 등은 용수 인프라 관리 또는 통합네트워크 솔루션 등의 통합 물관리 시스템(integrated water management system)을 개발하여 현장적용을 하고 있으며, 원격검침 시스템을 통해 고객들의 현재 소비량과 과거 누적 소비량, 누수 감지 서비스 및 실시간 요금 고지 등을 실시간으로 웹 포털과 앱을 통해 제공하고 있다. 또한, 일부 제조업체들은 도시 용수공급/소비 관리자가 주민의 용수사용량을 모니터링하여 일평균 용수사용량 및 사용 경향을 파악하고, 누수를 검지하여 복구 및 용수 사용 지속가능성 지수를 제시하고, 실시간으로 주민의 용수사용량 관련 데이터를 모니터링하여 용수공급의 최적화를 위한 의사결정지원 서비스를 용수공급자에게 제공하고 있다. 최근에는 인공지능을 활용해 가정용수의 용도별(세탁용수, 화장실용수, 샤워용수, 식기세척용수 등) 사용량 곡선을 패터닝하여 profiling 기법을 도입해, 스마트워터미터에서 용수사용량이 통합되어 검지될 시 용수사용량의 세부 용도별 re-profiling 기법을 도입하여 가정용수내 과소비되는 지점을 도출 후 절감을 유도하는 기술이 개발 중이다. 또한, 미래 용수 사용량 예측을 위해 다양한 시계열 자료를 분석하는 선형 종속 모형(자기회귀모형, 자기회귀이동평균모형, 자기회귀적분이동평균모형 등)과 비선형 종속 모형(Fuzzy Logic, Neural Network, Genetic Algorithm 등)을 활용한 예측기능이 구축되어 상호 비교하여 최적의 용수사용량 예측 도구를 제공되고 있다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.5
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• pp.105-112
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• 2011

Delay reduction of vehicles at the intersection is highly dependent on the signal operation method. Improper traffic operation causes the violation of the traffic regulations and increasing traffic congestion. Delay because of congestion has contributed to the increase in carbon dioxide in the atmosphere. The focus of this paper is to measure the amount of carbon dioxide when the intersection is changed to roundabout. Even though, Intergovernmental Panel on Climate Change(IPCC) recommends Tier 1 method to measure the amount of greenhouse gas from vehicles, this paper used Tier 3 method because we could use the data of average running distance per each vehicle model. Two signalized intersections were selected as the study area and the delay reductions of roundabout operation were estimated by VISSIM microscopic simulation tool. The control delay for boksu intersection reduced from 28.6 seconds to 4.4 seconds and the KRIBB intersection sharply reduced from 156.4 seconds to 23.6 seconds. In addition, carbon dioxide for two intersections reduced to 646.5 ton/year if the intersection is changed to roundabout. Future research tasks include testing the experiment for networks, as well as for various intersection types.

• Journal of the Institute of Convergence Signal Processing
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• v.4 no.1
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• pp.15-26
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• 2003

Ultrasonic inspection methods are widely used for detecting flaws in materials. The signal analysis step plays a crucial part in the data interpretation process. A number of signal processing methods have been proposed to classify ultrasonic flaw signals. One of the more popular methods involves the extraction of an appropriate set of features followed by the use of a neural network for the classification of the signals in the feature space. This paper describes an alternative approach which uses the least mean square (LMS) method and expectation maximization (EM) algorithm with the model based deconvolution which is employed for classifying nondestructive evaluation (NDE) signals from steam generator tubes in a nuclear power plant. The signals due to cracks and deposits are not significantly different. These signals must be discriminated to prevent from happening a huge disaster such as contamination of water or explosion. A model based deconvolution has been described to facilitate comparison of classification results. The method uses the space alternating generalized expectation maximization (SAGE) algorithm In conjunction with the Newton-Raphson method which uses the Hessian parameter resulting in fast convergence to estimate the time of flight and the distance between the tube wall and the ultrasonic sensor Results using these schemes for the classification of ultrasonic signals from cracks and deposits within steam generator tubes are presented and showed a reasonable performances.

• Korean Journal of Materials Research
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• v.9 no.12
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• pp.1263-1269
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• 1999

An FBAR(Solidly Mounted Resonator) was fabricated using reflector layers which prohibit the penetration of bulk acoustic wave into substrate. The SMR consisted of top and bottom electrodes(Al films), a piezoelectric layer (ZnO film), reflector layers(W/$Si_2$ films) and Si substrate. The electrodes were deposited by dc sputtering. The piezoelectric layer and the reflector layers were deposited by rf magnetron sputtering. The control of crystallinity, microstructures and electric properties of each layer was essential for attaining the optimum FBAR characteristics. Under the best deposition conditions for FBAR devices, the ZnO films had highly c-axis preferred orientation(${\sigma}=2.17^{\circ}$), resistivity of $10^4\;{\omega}cm$, and surface roughness of 10.6 ${\AA}$. On the other hand, the surface roughness of W and $Si_2$ films was 16 ${\AA}$ and 33 ${\AA}$, respectively, and the resistivity of Al film was $5.1{\times}10^{-6}\;{\Omega}cm$. The SMR devices were fabricated by the conventional semiconductor processes. In the resonance conditions of the SMR, the series resonance frequency (fs) and the parallel resonance frequency(fp) were 1.244 GHz and 1.251 GHz, respectively and the quality factor(Q) was 1200.

• Journal of Korean Society of Forest Science
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• v.107 no.4
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• pp.456-477
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• 2018

We analyzed the data on medicinal plants and related traditional knowledge in Korea and China using data analysis method. There are 108 families 214 genera 542 species, and 202 families 660 genera 1,261 species were found in Korea and China respectively. Total of 86 families (79.6%) and 130 genera (60.7%) were in common both countries. More than one information were recorded in many species, however, there was only one information from some species (32.7% of genera in Korea, and 58.8% of genera in China). The most frequent appeared plant family was Compositae (Asteraceae) in both countries (8.4% in Korea and 10.7% in China) and followed by Rosecease and Leguminocae (Fabaceae). Plant parts were classified 11 parts and roots were mostly used in Korea and whole plants in China. Usages were described in different terms of ailments or symptoms. There are 120 usage in Korea and 230 in China. Plant uses for the ailment or symptoms are pain, digestive system disorder, cold and etc. in Korea. In China, plants were mostly used for clear heat, digestive system disorder, cough and etc. Relation between the plant and ailment(symptom) of the top 10 plants in Korea and China was different although from same plant family. We also analyzed the relations between plant species and part used, and plants parts and ailment(symptom). With the data analysis method, we were able to collect the medicinal plant resources data and found the differences in plant resources, usage, and plant part for use. The result provide important information of the plant resources and related traditional knowledge of Korea for use of plant resources in industry and facilitate to plan a strategy to cope with Nagoya Protocol in the future.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.5 s.335
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• pp.31-38
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• 2005

The architecture and the implementation details of a UTMI(USB2.0 Transceiver Macrocell Interface) compatible USB2.0 transceiver chip were presented. To confirm the validation of the incoming data in noisy channel environment, a squelch state detector and a current mode Schmitt-trigger circuit were proposed. A current mode output driver to transmit 480Mbps data on the USB cable was designed and an on-die termination(ODT) which is controlled by a replica bias circuit was presented. In the USB system using plesiochronous clocking, to compensate for the frequency difference between a transmitter and a receiver, a synchronizer using clock data recovery circuit and FIFO was designed. The USB cable was modeled as the lossy transmission line model(W model) for circuit simulation by using a network analyzer measurements. The USB2.0 PHY chip was implemented by using 0.25um CMOS process and test results were presented. The core area excluding the IO pads was $0.91{\times}1.82mm^2$. The power consumptions at the supply voltage of 2.5V were 245mW and 150mW for high-speed and full-speed operations, respectively.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.2
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• pp.20-30
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• 1999

We have made the single side hand filter for the dual channel receiver which is a heterodyne receiver to observe the cosmic radio waves with 100GHz band ranged from 85GHz to 115GHz and 150GHz band ranged from 125GHz to 175GHz simultaneously. We have introduced the filter theory using the principle of the Martion-Puplett interferometer, which has the characteristics of rotated polarization. To reduce the loss of the transmission and beam coupling which are caused from the path difference associated with the intermediate frequency the design and the implementation have been intensely considered. The receiver needs two filters with different characteristics each other. Because each of them has the optimum positions as a function frequency at which the signal frequency is fed to mixer and the image frequency is rejected to the image termination load. The intermediate frequency and its band width have been also evaluated. We have measured the property of two filters using the vector network analyser and the beam measurement system which is made by us. The responses of the filter as a function of the position and the frequency are compared with the theory. It is shown that not only the measured values are very close to the theoretical values, but also the image rejection ratios are better than 22dB for both filters. Through successful observation using a dual channel receiver with two manufactured filters, the performance of the filters has finally verified.

• Journal of Korea Water Resources Association
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• v.38 no.4 s.153
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• pp.323-332
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• 2005

The Tumen River basin is relatively small(${\approx}33,000km^2$), it has many potential conflicts between the riparian countries. Especially, until recently, it could have not drawn the socio-potitical attention from its central governments because of the geopolitical unique characteristics as edges of mainlands. since 1990's the various plans have been suggested for resolving the problems in this area as an international attention from, e.g UNDP, began to be given. However, the international cooperative structure has not been established in systematic way which has paramount importance. In the research, based on the problems identified in the previous paper, the necessities for independent unit, so called 'Tumen River Watershed Management Commission' were suggested for holistic and hierarchical resolution in accordance with integrated management and international river based on 'limited territory sovereignty' which is a general principle in international river management. For this purposes, hierarchical problem solving approach which consists of 3 phases were developed. They include major objectives and behavioral guidelines for achieving equity between riparian countries based on international cooperation and integrated watershed management as fundamental concept. In conclusion, rational plan for future water use, management and primary framework of Tumen River for international cooperation were composed and strategic approach for the North-East Asian community foundation was suggested.

• Archives of design research
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• v.16 no.2
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• pp.395-404
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• 2003

As scenario-based design is expanded to various fields of design, it is introduced to HCI(Human Computer Interaction) in order to figure out user information & tasks. However, scenario based design methods that is focused on collecting scenarios regarding users'needs, is mainly utilized conceptual design stage for system itself. There is a gap between users'need scenarios to interface design of HCI system. In this study, web survey is suggested as scenario based interface design method in order to connect scenario collecting to task specification and to menu structure design of home-network controller. The degree of users'need for specified tasks was verified to various kinds of users through web survey and it decideddepth and order of menu structure. Tasks also was categorized to situation mode and users can make their own menu structure by selecting menu contents or even mode itself, because degrees of need for specified task situation were varied by lifestyle of user group. Finally, it is found that web survey method can be applied to collect and database various scenarios of. various users when a questionnaire is well designed for collection.

• Proceedings of the Korea Multimedia Society Conference
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• 1998.10a
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• pp.149-154
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• 1998

본 논문에서는 월드와이드웹상에서 3차원 인터페이스를 기술하는 표준 사양인 VRML과 자바의 EAI(External Authoring Interface)를 통하여 사용자 간에 발생하는 상호작용들을 동기화 시키는 방법을 소개한다. 제시한 방법에서는 별도의 독립적인 응용프로그램을 작성하거나 동기화를 위하여 확장된 VRML을 사용할 필요없이 웹브라우저와 바로 호환하여 사용할 수 있으며 기존의 방대한 웹문서와 연계가 쉬우므로 범용적인 자료구축이 가능하다. 하지만, 가장 최근의 VRML97에서조차도 VRML이 제시하는 가상공간 다중 사용자 환경의 지원은 아직 미비하다. 더 이상 단순히 3차원 월드를 탐험하는 시기는 지났으며, 같은 공간상에서 혼자가 아닌 여럿이 함께 하는 다중 사용자 환경을 제공해야 할 것이다. 이에 자바의 네트웍 기능과 가상공간의 외부에서 동적으로 월드를 제어할 수 있는 EAI를 이용하여 부족했던 다중 사용자 환경을 지원함으로써 가상 공간 시스템을 구축할 수 있다. 그러나, 가상 공간에서 일어나는 이벤트는 단지 동일 브라우저에서만 유효하기 때문에 다른 사용자에게 전달할 때는 이벤트를 원격지의 이벤트와 연동하기 위하여 다른 방법이 필요하다. 사용자 상호작용 시스템에 있어서 이러한 이벤트를 결정하는 가장 중요한 요소는 아바타의 행동양식(avatar's behavior)이라 할 수 있다. 가상 공간에서 일어나는 이벤트의 대부분이 사용자에 의해서 발생되는 것들이다. 즉, 아바타의 행위에 따라서 사용자 서로 간에 상호작용이 일어나게 되며 이들 이벤트를 서로 동기화 함으로써 실시간 3차원 상호작용 시스템을 구현한다. 이렇게 구현된 시스템을 구현한다. 이렇게 구현된 시스템은 전자 상거래, 가상 쇼핑몰, 가상 전시화, 또는 3차원 게임이나 가상교육 시스템과 같은 웹기반 응용프로그램에 사용될 수 있다.물을 보존·관리하는 것이 필요하다. 이는 도서관의 기능만으로는 감당하기 어렵기 때문에 대학정보화의 센터로서의 도서관과 공공기록물 전문 담당자로서의 대학아카이브즈가 함께 하여 대학의 공식적인 직무 관련 업무를 원활하게 지원하고, 그럼으로써 양 기관의 위상을 높이는 상승효과를 낼 수 있다.하여는, 인쇄된 일차적 정보자료의 검색방법등을 개선하고, 나아가서는 법령과 판례정보를 위한 효율적인 시스템을 구축하며, 뿐만 아니라 이용자의 요구에 충분히 대처할 수 잇는 도서관으로 변화되는 것이다. 이와 함께 가장 중요한 것은 법과대학과 사법연수원에서 법학 연구방법에 관한 강좌를 개설하여 각종 법률정보원의 활용 내지 도서관 이용방법에 관하여 교육하는 것이다.글을 연구하고, 그 결과에 의존하여서 우리의 실제의 생활에 사용하는 $\boxDr$한국어사전$\boxUl$등을 만드는 과정에서, 어떤 의미에서 실험되었다고 말할 수가 있는 언어과학의 연구의 결과에 의존하여서 수행되는 철학적인 작업이다. 여기에서는 하나의 철학적인 연구의 시작으로 받아들여지는 이 의미분석의 문제를 반성하여 본다. 것이 필요하다고 사료된다.크기에 의존하며, 또한 이러한 영향은 $(Ti_{1-x}AI_{x})N$ 피막에 존재하는 AI의 함량이 높고, 초기에 증착된 막의 업자 크기가 작을 수록 클 것으로 여겨진다. 그리고 환경의 의미의 차이에 따라 경관의 미학적 평가가 달라진 것으로 나타났다.corner$적 의도에 의한 경관구성의 일면을 확인할수 있지만 엄밀히 생각하여 보면 이러한 예의 경우도 최락의 총체적인 외형은 마찬가지로 $\ulcorner$순응$\lrcorner$의 범위를 벗어나지 않는다. 그렇기 때문에도 $\ulcorner$순응