• Journal of Korea Spatial Information System Society
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• v.5 no.1 s.9
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• pp.49-63
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• 2003

Recently, two international standard organizations, ISO and OGC, have done the work of standardization for GIS. Current standardization work for providing interoperability among GIS DB focuses on the design of open interfaces. But, this work has not considered procedures and methods for designing GIS DB. Eventually, GIS DB has its own model. When we share the data by open interface among heterogeneous GIS DB, differences between models result in the loss of information. Our aim in this paper is to revise the design guidelines for geographic information databases in order to make consistent spatial data models, logical structures, and semantic structure of populated geographical databases. In details, we propose standard guidelines which convert ISO abstract schema into relation model, object-relation model, object-centered model, and geometry-centered model. Furthermore, we provide sample models for applying these guidelines in commercial GIS S/Ws. Building GIS DB based on design guidelines proposed in the paper has the following advantages: the interoperability among databases, the standardization of schema definitions, and the catalogue of GIS databases through.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2006.11a
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• pp.279-282
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• 2006

IP망을 이용한 IPTV 방송 서비스가 새로운 수익 모델로 인정받고 현재 국내의 KT, SKT 등이 IPTV 시범서비스를 준비하거나 진행 중에 있다 이 IPTV 서비스는 이전의 단방향 방송과는 달리 사용자와의 인터렉션을 중시하는 양방향 방송을 표방하기 때문에 지금까지의 방송과는 다른 혁신적인 방송서비스가 기대된다. 하지만 IPTV 서비스에 있어서 여러 통신사와 방송사가 참여할 수 있을 것으로 보여지는 것과는 달리 실상은 몇몇 거대 통신기업이 자신들의 망을 이용하는 가입자들을 상대로 한정된 사업을 벌이고 있다. 이는 IPTV 서비스를 위한 인프라가 구축되어 있지 않고 방통융합망의 개념을 만족시키기 위해 서비스 개발자가 알아야 할 프로토콜들이 너무나 많기 때문이다. 따라서 본 논문에서는 이러한 상황을 타개할 수 있는 수단을 Open API로 제안한다. 맞춤형 방송을 위한 시나리오를 TV-Anytime의 벤치마킹과 유저 시나리오를 참고하여 재구성하고 이 시나리오로부터 IPTV 방송 서비스를 위한 방통융합망의 기본적이고 강력한 기능들을 Open API 함수로 정의하였다. 여기에서의 방송 서비스는 NDR, EPG, 개인 맞춤형 광고 서비스를 말하며 각 서비스를 위한 서버는 통합망 위에 존재하고 이 서버들이 개방하는 API들은 다른 응용프로그램에 의해 사용되는 것이기 때문에 가장 기본적인 기능을 정의하게 된다. 또한, 제안한 Open API 함수를 이용하여 개인 맞춤형 방송 응용 서비스를 구현함으로써 서비스 검증을 하였다. Open API는 웹서비스를 통해 공개된 기능들로써 게이트웨이를 통해 다른 망에서 사용할 수 있게 된다. Open API 함수의 정의는 함수 이름, 기능, 입 출력 파라메터로 이루어져 있다. 사용자 맞춤 서비스를 위해 전달되는 사용자 상세 정보와 콘텐츠 상세 정보는 TV-Anytime 포럼에서 정의한 메타데이터 스키마를 이용하여 정의하였다.가능하게 한다. 제안된 방법은 프레임 간 모드 결정을 고속화함으로써 스케일러블 비디오 부호화기의 연산량과 복잡도를 최대 57%감소시킨다. 그러나 연산량 감소에 따른 비트율의 증가나 화질의 열화는 최대 1.74% 비트율 증가 및 0.08dB PSNR 감소로 무시할 정도로 작다., 반드시 이에 대한 검증이 필요함을 알 수 있었다. 현지관측에 비해 막대한 비용과 시간을 절약할 수 있는 위성영상해석방법을 이용한 방법은 해양수질파악이 가능할 것으로 판단되며, GIS를 이용하여 다양하고 복잡한 자료를 데이터베이스화함으로써 가시화하고, 이를 기초로 공간분석을 실시함으로써 환경요소별 공간분포에 대한 파악을 통해 수치모형실험을 이용한 각종 환경영향의 평가 및 예측을 위한 기초자료로 이용이 가능할 것으로 사료된다.염총량관리 기본계획 시 구축된 모형 매개변수를 바탕으로 분석을 수행하였다. 일차오차분석을 이용하여 수리매개변수와 수질매개변수의 수질항목별 상대적 기여도를 파악해 본 결과, 수리매개변수는 DO, BOD, 유기질소, 유기인 모든 항목에 일정 정도의 상대적 기여도를 가지고 있는 것을 알 수 있었다. 이로부터 수질 모형의 적용 시 수리 매개변수 또한 수질 매개변수의 추정 시와 같이 보다 세심한 주의를 기울여 추정할 필요가 있을 것으로 판단된다.변화와 기흉 발생과의 인과관계를 확인하고 좀 더 구체화하기 위한 연구가 필요할 것이다.게 이루어질 수 있을 것으로 기대된다.는 초과수익률이 상승하지만, 이후로는 감소하므로, 반전거래전략을 활용하는 경우 주식투자기간은 24개월이하의 중단기가 적합함을 발견하였다. 이상의 행태적 측면과 투자성과측면의 실증결과를 통하여 한국주식시장에 있어서 시장수익률을 평균적으로 초과할 수 있는 거래전략은 존재하므로 이러한 전략을 개발 및 활용할 수 있으며, 특히, 한국주식시장에 적합한 거래전략은 반전거래전략이고, 이 전략의 유용성은 투자자가 설정한 투자기간보다

• Journal of Korean Society of Forest Science
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• v.61 no.1
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• pp.37-44
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• 1983

This study was to estimate total annual volume growth by the measurement of mean tree growth during the last 10 years. Surveyed Forest stand was the second block (20.80 ha.)of Kyung Hee University Forests located at San 58 and 64, Gaegok-Ri, Gapyung-Yeup, Gapyung-Goon, Kyunggi province in Korea. The stand was mainly composed of uneven-aged Pinus densiflora and the estimation of tree volume was conducted by taking the cores at the D.B.H. of the sample tree which was selected by sub-sampling. The results obtained were as follows; 1) The regression between the diameter (D) and diameter growth ($\hat{I}$) was $\hat{I}=0.5499+0.0101D$. 2) The estimated equation of confidence interval for the diameter growth was $S^2{\hat{I}}=0.00817(0.09538-0.00952D+0.00027D^2$) 3) The equation for estimating tree height (H) from diameter was $H=1.32376D^{0.77958}$ 4) The equation for estimating tree volume from diameter and height $V=0.0000622D^{1.6918}H^{1.1397}$ 5) Total annual tree volume growth was $5.4041m^3/ha$, and ranged from 5.6131 to $5.1984m^3/ha$. 6) Annual growth rate of total tree volume and its error were 8.8% and 3.9%, respectively. The annual volume growth per tree for any districts can be estimated by this method, and the annual volume growth will be successfully predicted. Because of poor forest growing stock in Korea, annual amount of allowable cut should not exceed annual tree volume growth for better forest management. Accordingly, annual amount of allowable cut should be either equal to or less than annual tree volume growth for the balanced establishment between timber supply and demand in Korea. Demand shortage will be substituted with imported timber. Such plans enable Korean Government to develop a better policy of forest resources management.

• Journal of Wetlands Research
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• v.23 no.4
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• pp.287-295
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• 2021

As facilities such as dam reservoir wetlands and agricultural irrigation reservoir wetlands are built, sedimentation occurs over time through erosion, sedimentation transport, and sediment deposition. Sedimentation issues are very important for the maintenance of reservoir wetlands because long-term sedimentation of sediments affects flood and drought control functions. However, research on resignation has been estimated mainly by empirical formulas due to the lack of available data. The purpose of this study was to calculate and compare the sediment deposition rate by developing a multiple regression model along with actual data and empirical formulas. In addition, it was attempted to identify potential causes of collapse by applying it to 64 reservoir wetlands that suffered flood damage due to the long rainy season in 2020 due to reservoir wetland sedimentation and aging. For the target reservoir, 10 locations including the GaGog reservoir located in Miryang city, Gyeongsangnam province in South Korea, where there is actual survey information, were selected. A multiple regression model was developed in consideration of physical and climatic characteristics, and a total of four empirical formulas and sediment deposition rate were calculated. Using this, the error of the sediment deposition rate was compared. As a result of calculating the sediment deposition rate using the multiple regression model, the error was the lowest from 0.21(m³km²/yr) to 2.13(m³km²/yr). Therefore, based on the sediment deposition rate estimated by the multi-regression model, the change in the available capacity of reservoir wetlands was analyzed, and the effective storage capacity was found to have decreased from 0.21(%) to 16.56(%). In addition, the sediment deposition rate of the reservoir where the overflow damage occurred was relatively higher than that of the reservoir where the piping damage occurred. In other words, accumulating sediment deposition rate at the bottom of the reservoir would result in a lack of acceptable effective water capacity and reduced reservoir flood and drought control capabilities, resulting in reservoir collapse damage.

• Journal of Korean Society of Forest Science
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• v.110 no.3
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• pp.322-340
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• 2021

Due to climate change and its consequential spring temperature rise, flowering time of Robinia pseudoacacia has advanced and a simultaneous blooming phenomenon occurred in different regions in South Korea. These changes in flowering time became a major crisis in the domestic beekeeping industry and the demand for accurate prediction of flowering time for R. pseudoacacia is increasing. In this study, we developed and compared performance of four different models predicting flowering time of R. pseudoacacia for the entire country: a Single Model for the country (SM), Modified Single Model (MSM) using correction factors derived from SM, Group Model (GM) estimating parameters for each region, and Local Model (LM) estimating parameters for each site. To achieve this goal, the bloom date data observed at 26 points across the country for the past 12 years (2006-2017) and daily temperature data were used. As a result, bloom dates for the north central region, where spring temperature increase was more than two-fold higher than southern regions, have advanced and the differences compared with the southwest region decreased by 0.7098 days per year (p-value=0.0417). Model comparisons showed MSM and LM performed better than the other models, as shown by 24% and 15% lower RMSE than SM, respectively. Furthermore, validation with 16 additional sites for 4 years revealed co-krigging of LM showed better performance than expansion of MSM for the entire nation (RMSE: p-value=0.0118, Bias: p-value=0.0471). This study improved predictions of bloom dates for R. pseudoacacia and proposed methods for reliable expansion to the entire nation.

• Journal of Korea Water Resources Association
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• v.48 no.7
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• pp.553-566
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• 2015

Acoustic Doppler Current Profilers(ADCPs) have capability to concurrently capitalize three-dimensional velocity vector and bathymetry with highly efficient and rapid manner, and thereby enabling ADCPs to document the hydrodynamic and morphologic data in very high spatial and temporal resolution better than other contemporary instruments. However, ADCPs are also limited in terms of the inevitable unmeasured regions near bottom, surface, and edges of a given cross-section. The velocity in those unmeasured regions are usually extrapolated or assumed for calculating flow discharge, which definitely affects the accuracy in the discharge assessment. This study aimed at scrutinizing a conventional extrapolation method(i.e., the 1/6 power law) for estimating the unmeasured regions to figure out the accuracy in ADCP discharge measurements. For the comparative analysis, we collected spatially dense velocity data using ADV as well as stationary ADCP in a real-scale straight river channel, and applied the 1/6 power law for testing its applicability in conjunction with the logarithmic law which is another representative velocity law. As results, the logarithmic law fitted better with actual velocity measurement than the 1/6 power law. In particular, the 1/6 power law showed a tendency to underestimate the velocity in the near surface region and overestimate in the near bottom region. This finding indicated that the 1/6 power law could be unsatisfactory to follow actual flow regime, thus that resulted discharge estimates in both unmeasured top and bottom region can give rise to discharge bias. Therefore, the logarithmic law should be considered as an alternative especially for the stationary ADCP discharge measurement. In addition, it was found that ADCP should be operated in at least more than 0.6 m of water depth in the left and right edges for better estimate edge discharges. In the future, similar comparative analysis might be required for the moving boat ADCP discharge measurement method, which has been more widely used in the field.

• The Transactions of the Korea Information Processing Society
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• v.5 no.10
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• pp.2575-2583
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• 1998

The productionof the highly relible softwae systems and theirs performance evaluation hae become important interests in the software industry. The software evaluation has been mainly carried out in ternns of both reliability and performance of software system. Software reliability is the probability that no software error occurs for a fixed time interval during software testing phase. These theoretical software reliability models are sometimes unsuitable for the practical testing phase in which a software error at a certain testing stage occurs by causes of the imperfect debugging, abnornal software correction, and so on. Such a certatin software testing stage needs to be considered as an outlying stage. And we can assume that the software reliability does not improve by means of muisance factor in this outlying testing stage. In this paper, we discuss Bavesian software reliability growth modeling and estimation procedure in the presence of an imidentitied outlying software testing stage by the modification of Jehnski Moranda. Also we derive the Bayes estimaters of the software reliability panmeters by the assumption of prior information under the squared error los function. In addition, we evaluate the proposed software reliability growth model with an unidentified outlying stage in an exchangeable model according to the values of nuisance paramether using the accuracy, bias, trend, noise metries as the quantilative evaluation criteria through the compater simulation.

• Journal of The Korean Society of Grassland and Forage Science
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• v.27 no.4
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• pp.297-312
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• 2007

This study is conducted to evaluate economical value of Jeju grassland and validity of its preservation, and draw up several measures to support. To measure its economical value, this study examined its environmental value and social and cultural value. For environmental value, this study used replacement method while it applied CVM method, a widely used method, to assess social and cultural value and two-level two-best choice selection method, which ask questions by assuming virtual circumstances to avoid reflecting some biased opinions. Jeju grassland has multiple functions-environmental functions such as preventing soil corrosion and flood, handling animal excrement, and purifying air, and social and cultural functions such as promoting physical and mental health and providing recreation places. From the results of the feasibility study, Jeju grassland's annual multiple functions are assessed to have a total $397,115{\sim}418,995$ million won worth. In addition, it is found that Jeju visitors recognize Jeju grassland for its functions to contribute to public interests. That is, they think it can provide attractive views and educational and recreational places and promote emotional development. Especially, many people presented their ideas that it be continuously preserved since it is worthwhile for us and our next generations. To preserve grassland's cultural resource, which create a huge economic value like this, the Government has to support a certain amount of financial aid for turning to a better grassland environment and its maintenance to realize environment-friendly livestock farming on Jeju Island and promote its tourism industry and consequently, add more value to Jeju.

• Korean Journal of Remote Sensing
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• v.37 no.5_1
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• pp.959-974
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• 2021

Forel-Ule Index (FUI) is an index which classifies the colors of inland and seawater exist in nature into 21 gradesranging from indigo blue to cola brown. FUI has been analyzed in connection with the eutrophication, water quality, and light characteristics of water systems in many studies, and the possibility as a new water quality index which simultaneously contains optical information of water quality parameters has been suggested. In thisstudy, Ocean Colour-Climate Change Initiative (OC-CCI) based 4 km FUI was spatially downscaled to the resolution of 500 m using the Geostationary Ocean Color Imager (GOCI) data and Random Forest (RF) machine learning. Then, the RF-derived FUI was examined in terms of its correlation with various water quality parameters measured in coastal areas and its spatial distribution and seasonal characteristics. The results showed that the RF-derived FUI resulted in higher accuracy (Coefficient of Determination (R²)=0.81, Root Mean Square Error (RMSE)=0.7784) than GOCI-derived FUI estimated by Pitarch's OC-CCI FUI algorithm (R²=0.72, RMSE=0.9708). RF-derived FUI showed a high correlation with five water quality parameters including Total Nitrogen, Total Phosphorus, Chlorophyll-a, Total Suspended Solids, Transparency with the correlation coefficients of 0.87, 0.88, 0.97, 0.65, and -0.98, respectively. The temporal pattern of the RF-derived FUI well reflected the physical relationship with various water quality parameters with a strong seasonality. The research findingssuggested the potential of the high resolution FUI in coastal water quality management in the Korean Peninsula.

• Korean Journal of Food Science and Technology
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• v.37 no.3
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• pp.352-359
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• 2005

Uncertainty involved during determination of vitamin C content in infant formula was quantified by indophenol titration method. Uncertainty sources in measurand, such as purity, weight, final volume of standard, volume of standard solution used for titration, sample weight, final volume of sample, extraction solution used for titration, titration of extraction solution and standard solution by indophenol solution were identified and used as parameters for combined standard uncertainty based on Guide to the expression of uncertainty in measurement (GUM) and Draft EURACHEM/CITAC Guide. Uncertainty parameters of each source in measurand were identified as resolution, reproducibility and stability of chemical balance, standard material purity, repeatability, reproducibility, end point of titration, 1 mL pipet, 5 mL autopipet, and 100 mL mass flask. Each uncertainty component was evaluated by types A and B and included to calculate combined uncertainty. Analytical test result for traceability under laboratorial conditions using Certified Reference Material (CRM) test was certified as $108.4{\pm}1.7mg/100g$, which was within CRM certification range of $114.6{\pm}6.6mg/100g$. Uncertainty test result of vitamin C content of 5 g sampling was $56.7{\pm}2.44mg/100g$. Uncertainty could be reduced by identification of uncertainty sources and components related with vitamin C determination by indophenol titration method and by decreasing uncertainty sources and components.