• Fisheries and Aquatic Sciences
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• 제14권3호
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• pp.218-225
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• 2011

Dual frequency identification sonar (DIDSON) is an imaging sonar that has been used for numerous fisheries investigations in a diverse range of freshwater and marine environments. The main purpose of DIDSON is fish counting, fish sizing, and fish behavioral studies. DIDSON records video-quality data, so processing power for handling the vast amount of data with high speed is a priority. Therefore, a semiautomated analysis of DIDSON data for fish counting, sizing, and fish behavior in Echoview (fisheries acoustic data analysis software) was accomplished using testing data collected on the Rakaia River, New Zealand. Using this data, the methods and algorithms for background noise subtraction, image smoothing, target (fish) detection, and conversion to single targets were precisely illustrated. Verification by visualization identified the resulting targets. As a result, not only fish counts but also fish sizing information such as length, thickness, perimeter, compactness, and orientation were obtained. The alpha-beta fish tracking algorithm was employed to extract the speed, change in depth, and the distributed depth relating to fish behavior. Tail-beat pattern was depicted using the maximum intensity of all beams. This methodology can be used as a template and applied to data from BlueView two-dimensional imaging sonar.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전력기술부문
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• pp.283-285
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• 2005

This paper presents a new two-terminal numerical algorithm for fault location estimation and for faults recognition using the synchronized phasor in time-domain. The proposed algorithm is also based on the synchronized voltage and current phasor measured from the PMUs(Phasor Measurement Units) installed at both ends of the transmission lines. Also the arc voltage wave shape is modeled numerically on the basis of a great number of arc voltage records obtained by transient recorder. From the calculated arc voltage amplitude it can make a decision whether the fault is permanent or transient. In this paper the algorithm is given and estimated using DFT(Discrete Fourier Transform) and the LES(Least Error Squares Method). The algorithm uses a very short data window and enables fast fault detection and classification for real-time transmission line protection. To test the validity of the proposed algorithm, the Electro-Magnetic Transient Program(EMTP/ATP) and MATLAB is used.

• Animal Systematics, Evolution and Diversity
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• 제21권2호
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• pp.259-272
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• 2005

한국산 해송류는 1과 2속 3종이 보고되어 있으며, 본 연구에서는 2003년부터 2005년까지 제주도에서 채집된 해송류로부터 3종인 빗자루해송 (Antipathes densa), 큰꽃해송 (A. grandiflora) 및 망해송 (A. dubia)이 새로이 한국 미기록종으로 보고된다. 이들은 주로 생태, 산호체의 분지양상, 폴립과 가시의 크기와 배열 및 자포형에 근거를 두고 기재를 하였다. 3종류의 자포형인 spirocysts, basitrichs, microbasic p-mastigophores를 지니고 있었으며, spirocysts와 basitrichs는 촉수에 분포하였고, microbasic p-mastigophores는 주로 격막사에 존재하였다.

• ALGAE
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• 제17권3호
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• pp.145-151
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• 2002

Three species of marine algae, two browns and one red were newly reported from the eastern and the southern coast of Korea including Cheju Island. their vegetative and reproductive structures were described. Colpomenia phaeodactyla Wynne et J.N. Norris (Scytosiphonaceae, Phaeophyceae) commonly occured in middle to lower intertidal zone of southern coast. Plants consisted of clusters of elongated and hollow sacs arising from an adherent colpomenioid base. Plurilocular sporangia were multiseriate, forming dense, extensive sori over the erect sacs. Cutleria adspersa (Mertens ex Roth) De Notaris (Cutleriaceae, Phaeophyceae) was collected from subtidal region of Cheju Island. It was characterized by broadly fan-shaped habits with golden brown colour and hair-fringed margines, attached by rhizoids along undersurface. Halarachnion latissimum Okamura (Furcellariaceae, Rhodophyceae) was found adrift from several areas of southern coast. Plants were brownish red, filmy and dlicate, membranaceous roundish fronds. Cystocarps were globular and formed under the cortical layer. Tetrasporangia were oblong and zonately divided.

• ALGAE
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• 제27권1호
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• pp.1-8
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• 2012

Here we report the first finding of Cryptonemia rotunda and Schizymenia apoda in Korea based on plastid rbcL sequence analysis and morphological observations. C. rotunda occurred in the subtidal in Hongdo and Namyeodo on the south coast. Thalli have short stipe with foliose, membranous blades with dentate margin, a length of 2-8 cm. S. apoda occurred in many locations along the coast of Korea. Thalli are foliose, simple or broadly lanceolate blades with irregular lobes and proliferations from the margins, sometimes undulate, soft fleshy, and slippery, up to 32 cm tall, and have cystocarps with ostioles on the blade. Plastid rbcL sequences reveal that each of these species is clearly separated from other species of their respective genera. S. apoda was well resolved within the genus. However, C. rotunda was distantly related to other members of the genus, and this result needs an urgent revision of the genus.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권5호
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• pp.1717-1732
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• 2015

The widespread use of location-based services (LBSs), which allows untrusted service provider to collect large number of user request records, leads to serious privacy concerns. In response to these issues, a number of LBS privacy protection mechanisms (LPPMs) have been recently proposed. However, the evaluation of these LPPMs usually disregards the background knowledge that the adversary may possess about users' contextual information, which runs the risk of wrongly evaluating users' query privacy. In this paper, we address these issues by proposing a generic formal quantification framework,which comprehensively contemplate the various elements that influence the query privacy of users and explicitly states the knowledge that an adversary might have in the context of query privacy. Moreover, a way to model the adversary's attack on query privacy is proposed, which allows us to show the insufficiency of the existing query privacy metrics, e.g., k-anonymity. Thus we propose two new metrics: entropy anonymity and mutual information anonymity. Lastly, we run a set of experiments on datasets generated by network based generator of moving objects proposed by Thomas Brinkhoff. The results show the effectiveness and efficient of our framework to measure the LPPM.

• Geomechanics and Engineering
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• 제10권3호
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• pp.269-284
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• 2016

Simplified techniques based on in situ testing methods are commonly used to assess seismic liquefaction potential. Many of these simplified methods were developed by analyzing liquefaction case histories from which the liquefaction boundary (limit state) separating two categories (the occurrence or non-occurrence of liquefaction) is determined. As the liquefaction classification problem is highly nonlinear in nature, it is difficult to develop a comprehensive model using conventional modeling techniques that take into consideration all the independent variables, such as the seismic and soil properties. In this study, a modification of the Multivariate Adaptive Regression Splines (MARS) approach based on Logistic Regression (LR) LR_MARS is used to evaluate seismic liquefaction potential based on actual field records. Three different LR_MARS models were used to analyze three different field liquefaction databases and the results are compared with the neural network approaches. The developed spline functions and the limit state functions obtained reveal that the LR_MARS models can capture and describe the intrinsic, complex relationship between seismic parameters, soil parameters, and the liquefaction potential without having to make any assumptions about the underlying relationship between the various variables. Considering its computational efficiency, simplicity of interpretation, predictive accuracy, its data-driven and adaptive nature and its ability to map the interaction between variables, the use of LR_MARS model in assessing seismic liquefaction potential is promising.

• 한국경영과학회지
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• 제26권3호
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• pp.21-37
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• 2001

Riding on the wave of the information technology revolution, a slow of internet venture businesses (IVB) came into being. Hence, one of the recent developments in Korean capital market has been the proliferation of IVB, which is in accordance with the worldwide trend of ‘new economy’. Although the fair valuation is crucial for the nourishment of IVB, it is difficult to apply traditional valuation methods to these firms without reservation. It is due to the facts that most venture firms have little records of performance, grow unprecedently fast, and have highly uncertain future. The main purpose of this study is to suggest performance evaluation system of IVB and to develop KPE (Key Performance Indicators). Our empirical study is based upon Kaplan & Norton’s Balance Scorecard (BSC) approach. Specifically, our research has been conducted by the following two subsequent procedures: Firstly, seven internet venture firms have been selected and their executives have been interviewed by FGI(Focus Group Interview) method. Based upon these results, performance indicators have been developed. Secondly, by using the above mentioned BSC items (i.e., financial perspective, customer perspective, internal perspective and innovation & learning perspective), questionnaires have been constructed and sent to IVB through e-mail as well as over the Fax. Among the collected 110 samples, reliable 106 samples have been used to build BSC model and to draw our conclusion. In the future study, it would be much better to consider the role of strategy in IVB and the causal relationship among Key Performance Indicators of BSC.

• 정보보호학회논문지
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• 제26권3호
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• pp.809-820
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• 2016

스마트그리드는 사물인터넷의 핵심 응용서비스이고, 그 중 가장 핵심적인 구성요소인 AMI((Advanced Metering Infrastructure)는 전기사업자와 소비자의 접점에 위치하고 있으며, 스마트 미터는 소비자의 전기사용을 기록하고 사업자에게 전달하는 역할을 한다. 본 논문에서는 스마트그리드에서 소비자와 직접 맞닿아 있는 스마트 미터를 중심으로 AMI에 대한 NESCOR에서 제시하고 있는 사이버공격 및 피해 시나리오를 기반으로 피해비용을 산정한다. 본 연구의 결과는 정책입안자나 전기사업자가 스마트그리드 관련 투자의사결정을 하는데 참고가 될 수 있을 것이다.

• 한국조경학회지
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• 제29권2호
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• pp.68-76
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• 2001

The purpose of this study is to computerize street tree management using a CAD program in order to manage the drawing record of street trees systematically and concurrently. The configuration of this program is composed of Reference Data, Data Inquiry, and Cost Assessment. The Reference Data includes characteristics of trees, monthly managements records, damage by blight and insects and usage of pesticides. The Data Inquiry includes an individual search of the tree index, simple searches and multiple searches. The Cost Assessment includes two main components, the data input with labor cost, manure ocst and pesticide cost and the assesment of management cost for prevention of blight and insects, pruning and fertilization. The results of this study are as follows: 1) When there are practices such as transplanting and removing of street trees it is immediately updated with the various situation. By creating an in progress a tree management system, up to the date information can be given to the manager for decision making. 2) To identify individual tree at the site or in drawing, the street name and numbers were used instead of coordinates. Tree tags are attached to the street trees individually. It can make DB management simple and easy. 3) By doing simple or multiple search with constructed DB, data can be provided quickly. 4) The result of this type of search are useful in the assessment of management cost very useful in regards to items such as the pruning, pesticides scattering and fertilization. 5) By using the AutoCAD software and existing PC without purchasing new equipment, the cost of system implementation can be minimized.