• Title/Summary/Keyword: Variable Input

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The Study on the Economic Appraisal of Fishing Port Investments (어항투자사업의 경제성 평가에 관한 연구)

  • 정형찬
    • The Journal of Fisheries Business Administration
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    • v.14 no.2
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    • pp.15-68
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    • 1983
  • From the economic point of view the fishing port is the complex of installations on land, organized to serve the fishing fleet and its cargo, and is the main link in the production chain of all components of the fishing industry, with the aim of achieving the planned targets with the minimum cost. Fishing port investment decisions have had significant impact on the development aims of Korean fisheries. Fishing port investments in Korea are made mostly by public or semipublic port authorities. Such investments should be judged not purely on the basis of financial profitability but rather on the extent to which they serve the development aims of the fishing industry. This makes the economic appraisal process more complex and presents certain problems in correctly quantifying the economic costs and benefits of the fishing port projects. This study concentrates more on the theoretical economic appraisal models than on the purely financial aspects of fishing port investments and points out the difference between the two approaches. In the result, there is clearly an element of judgment as to whether or not a shadow price needs to be used in estimating economic benefits and costs. From this viewpoint, some attempts are made to provide definitions of the possible economic benefits and costs, and methods for estimating and evaluating them in Part III and IV. Especially queueing theory is applied in the calculation of economic benefits. When a project is contemplated and analysis shows it to Lave a positive NPV, one question that arises is whether it should be implemented now or delayed. In this paper, the first year rate of return method is regarded as a more concise way of solving the timing of investment, At the end of Part IV, risk analysis of fishing port investments is considered. It can be handled in a number of ways, ranging from informal judgment to complex statistical analyses involving large-scale computer models, This paper recommends that evaluators of fishing port investments use the sensitivity analysis indicating exactly how much NPV will change in response to a given change in an input variable, other things held constant. Decisions regarding the amount of capacity to provide must be made in fishing port investments. Providing too much service would involve excessive capital costs. On the other hand, not providing enough service capacity would cause the waiting line of fishing vessels to become excessively long at times. Therefore, in Part V, the optimal number of berths and berth productivity in fishing port are defined as follows: Minimize E(TC) = E(WC)+E(SC) The minimum of this function is the solution and that is the optimal number of berth and berth productivity in fishing port.

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A Spatial Analysis about Arrival Delay and Dispatch Distribution of the 119 Rescue-Aid Service utilizing GIS - Gyeongsangbuk-Do Case Study - (GIS를 활용한 119 구조구급서비스의 도착지체 및 출동배치에 대한 공간분석 - 경상북도 사례 연구 -)

  • Oh, Chang-Seok;Lee, Seungwon;Lee, Inmook;Kho, Seung-Young
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.1D
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    • pp.13-22
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    • 2012
  • The 119 emergency rescue-aid service operated by Korean government is a very valuable in a society and its importance is growing in Korea as an aging society. Especially, the emergency vehicle's arrival time to accidents place is an important variable which affects initial emergency measure for patients and it depends on the road network attributes, such as emergency service station's location, accessibility to accidents place and so on. This study aims to analysis the emergency vehicles' arrival delay and the dispatch station in the viewpoint of efficiency utilizing the real rescue-aid activity data. We analyzed the dispatch distribution of the emergency rescue-aid service at first. And we analyzed high accident rate locations not involved in the fixed radius of rescue-aid service stations and display GIS map showing regions have been delayed. The input data of the road network speed is based on the KTDB (Korea Transportation Database) and historical rescue-aid data is from Gyeongsangbuk-do's fire service headquarters.

Construction and Application of Network Design System for Optimal Water Quality Monitoring in Reservoir (저수지 최적수질측정망 구축시스템 개발 및 적용)

  • Lee, Yo-Sang;Kwon, Se-Hyug;Lee, Sang-Uk;Ban, Yang-Jin
    • Journal of Korea Water Resources Association
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    • v.44 no.4
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    • pp.295-304
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    • 2011
  • For effective water quality management, it is necessary to secure reliable water quality information. There are many variables that need to be included in a comprehensive practical monitoring network : representative sampling locations, suitable sampling frequencies, water quality variable selection, and budgetary and logistical constraints are examples, especially sampling location is considered to be the most important issues. Until now, monitoring network design for water quality management was set according to the qualitative judgments, which is a problem of representativeness. In this paper, we propose network design system for optimal water quality monitoring using the scientific statistical techniques. Network design system is made based on the SAS program of version 9.2 and configured with simple input system and user friendly outputs considering the convenience of users. It applies to Excel data format for ease to use and all data of sampling location is distinguished to sheet base. In this system, time plots, dendrogram, and scatter plots are shown as follows: Time plots of water quality variables are graphed for identifying variables to classify sampling locations significantly. Similarities of sampling locations are calculated using euclidean distances of principal component variables and dimension coordinate of multidimensional scaling method are calculated and dendrogram by clustering analysis is represented and used for users to choose an appropriate number of clusters. Scatter plots of principle component variables are shown for clustering information with sampling locations and representative location.

NIR-TECHNOLOGY FOR RATIONALE SOIL ANALYSIS WITH IMPLICATIONS FOR PRECISION AGRICULTURE

  • Stenberg, Bo
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1061-1061
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    • 2001
  • The scope of precision agriculture is to reach the put up cultivation goals by adjusting inputs as precise as possible after what is required by the soil and crop potentials, on a high spatial resolution. Consequently, precision agriculture is also often called site specific agriculture. Regulation of field inputs “on the run” has been made possible by the GPS (Geographical Position System)-technology, which gives the farmer his exact real time positioning in the field. The general goal with precision agriculture is to apply inputs where they best fill their purpose. Thus, resources could be saved, and nutrient losses as well as the impact on the environment could be minimized without lowering total yields or putting product quality at risk. As already indicated the technology exists to regulate the input based on beforehand decisions. However, the real challenge is to provide a reliable basis for decision-making. To support high spatial resolution, extensive sampling and analysis is required for many soil and plant characteristics. The potential of the NIR-technology to provide rapid, low cost analyses with a minimum of sample preparation for a multitude of characteristics therefore constitutes a far to irresistible opportunity to be un-scrutinized. In our work we have concentrated on soil-analysis. The instrument we have used is a Bran Lubbe InfraAlyzer 500 (1300-2500 nm). Clay- and organic matter-contents are soil constituents with major implications for most properties and processes in the soil system. For these constituents we had a 3000-sample material provided. High performance models for the agricultural areas in Sweden have been constructed for clay-content, but a rather large reference material is required, probably due to the large variability of Swedish soils. By subdividing Sweden into six areas the total performance was improved. Unfortunately organic matter was not as easy to get at. Reliable models for larger areas could not be constructed. However, through keeping the mineral fraction of the soil at minimal variation good performance could be achieved locally. The influence of a highly variable mineral fraction is probably one of the reasons for the contradictory results found in the literature regarding organic matter content. Tentative studies have also been performed to elucidate the potential performance in contexts with direct operational implications: lime requirement and prediction of plant uptake of soil nitrogen. In both cases there is no definite reference method, but there are numerous indirect, or indicator, methods suggested. In our study, field experiments where used as references and NIR was compared with methods normally used in Sweden. The NIR-models performed equally or slightly better as the standard methods in both situations. However, whether this is good enough is open for evaluation.

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Quantifying Uncertainty for the Water Balance Analysis (물수지 분석을 위한 불확실성 정량화)

  • Lee, Seung-Uk;Kim, Young-Oh;Lee, Dong-Ryul
    • Journal of Korea Water Resources Association
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    • v.38 no.4 s.153
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    • pp.281-292
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    • 2005
  • The water balance analysis for the long-term water resources plan is a simple calculation that compares water demands with possible water supplies. For a watershed being considered the reports on the performance of the water balance analysis, however, have shown inconsistent results and thus have not earned credibility due to the uncertainty of the data acquired and models used. In this research, uncertainties in the water scarcity estimate were assessed through probability representation based on the Monte Carlo simulation using Latin Hypercube Sampling (LHS). The natural flow, municipal demand, industrial demand, agricultural demand, and return flow rate were selected as representative input variables for the water balance analysis, and their distributions were set based on the linear regression and the entropy theory. The statistical properties of the output variable samples were analyzed in comparison with a deterministic estimate of the water scarcity of an existing study. Application of LHS to three sub-basins of the Geum river basin showed the deterministic estimate could be overestimated or underestimated. The sensitivity analysis as well as the uncertainty analysis found that the return flow rate of the agricultural water is the most uncertain but is rarely sensitive to the output of the water balance analysis.

Interactions between Soil Moisture and Weather Prediction in Rainfall-Runoff Application : Korea Land Data Assimilation System(KLDAS) (수리 모형을 이용한 Korea Land Data Assimilation System (KLDAS) 자료의 수문자료에 대한 영향력 분석)

  • Jung, Yong;Choi, Minha
    • 한국방재학회:학술대회논문집
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    • 2011.02a
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    • pp.172-172
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    • 2011
  • The interaction between land surface and atmosphere is essentially affected by hydrometeorological variables including soil moisture. Accurate estimation of soil moisture at spatial and temporal scales is crucial to better understand its roles to the weather systems. The KLDAS(Korea Land Data Assimilation System) is a regional, specifically Korea peninsula land surface information systems. As other prior land data assimilation systems, this can provide initial soil field information which can be used in atmospheric simulations. For this study, as an enabling high-resolution tool, weather research and forecasting(WRF-ARW) model is applied to produce precipitation data using GFS(Global Forecast System) with GFS embedded and KLDAS soil moisture information as initialization data. WRF-ARW generates precipitation data for a specific region using different parameters in physics options. The produced precipitation data will be employed for simulations of Hydrological Models such as HEC(Hydrologic Engineering Center) - HMS(Hydrologic Modeling System) as predefined input data for selected regional water responses. The purpose of this study is to show the impact of a hydrometeorological variable such as soil moisture in KLDAS on hydrological consequences in Korea peninsula. The study region, Chongmi River Basin, is located in the center of Korea Peninsular. This has 60.8Km river length and 17.01% slope. This region mostly consists of farming field however the chosen study area placed in mountainous area. The length of river basin perimeter is 185Km and the average width of river is 9.53 meter with 676 meter highest elevation in this region. We have four different observation locations : Sulsung, Taepyung, Samjook, and Sangkeug observatoriesn, This watershed is selected as a tentative research location and continuously studied for getting hydrological effects from land surface information. Simulations for a real regional storm case(June 17~ June 25, 2006) are executed. WRF-ARW for this case study used WSM6 as a micro physics, Kain-Fritcsch Scheme for cumulus scheme, and YSU scheme for planetary boundary layer. The results of WRF simulations generate excellent precipitation data in terms of peak precipitation and date, and the pattern of daily precipitation for four locations. For Sankeug observatory, WRF overestimated precipitation approximately 100 mm/day on July 17, 2006. Taepyung and Samjook display that WRF produced either with KLDAS or with GFS embedded initial soil moisture data higher precipitation amounts compared to observation. Results and discussions in detail on accuracy of prediction using formerly mentioned manners are going to be presented in 2011 Annual Conference of the Korean Society of Hazard Mitigation.

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A Study on Characteristic Analysis of Single-Stage High Frequency Resonant Inverter Link Type DC-DC Converter (단일 전력단 고주파 공진 인버터 링크형 DC-DC 컨버터의 특성해석에 관한 연구)

  • Won, Jae-Sun;Park, Jae-Wook;Seo, Cheol-Sik;Cho, Gyu-Pan;Jung, Do-Young;Kim, Dong-Hee
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.2
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    • pp.16-23
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    • 2006
  • This paper presents a novel single-stage high frequency resonant inverter link type DC-DC converter using zero voltage switching with high power-factor. The proposed topology is integrated half-bridge boost rectifier as power factor corrector(PFC) and half-bridge high frequency resonant converter into a single-stage. The input stage of the half-bridge boost rectifier works in discontinuous conduction mode(DCM) with constant duty cycle and variable switching frequency. So that a boost converter makes the line current follow naturally the sinusoidal line voltage waveform. Simulation results have demonstrated the feasibility of the proposed high frequency resonant converter. Characteristics values based on characteristics analysis through circuit analysis is given as basis data in design procedure. Also, experimental results are presented to verify theoretical discussion. This proposed inverter will be able to be practically used as a power supply in various fields as induction heating applications, fluorescent lamp and DC-DC converter etc.

Distribution of Dissolved Heavy Metals in Surface Seawaters Around a Shipyard in Gohyun Bay, Korea (고현만의 조선소 주변 표층해수 중의 용존 중금속 농도 분포)

  • Kim, Kyung Tae;Ra, Kongtae;Kim, Joung Keun;Kim, Eun Soo;Kim, Chong Kwan;Shim, Won Joon
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.18 no.1
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    • pp.36-44
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    • 2015
  • The spatial and temporal distribution of dissolved trace metals has been studied to identify trends in space and time and to evaluate the pollution status in a semi-closed bay (Gohyun bay), Korea. Surface seawater samples were collected over four seasons at 18 stations in the bay between 2003 and 2004 and once at 7 stations around a large shipyard in May 2004. The concentration of Cd, Co, Cu, Ni, Pb, and Zn in seawater in February and May were highly variable in space, showing the higher value relative to other season. Those metals concentrations were decreased from inner-to outer-stations. In around the shipyard, Cu, Pb and Zn showed the higher variability depending on time. Cu and Zn concentrations at the sites around the shipyard had 2 times higher values compared with the average of inner stations in Gohyun bay. The very high correlations between salinity and either Cu and Zn has been showed. Especially, there was a significant relationship between Cu and Zn. We recognize that the shipyard is major source of Cu and Zn in seawater. Therefore, marine environment management policy such as the prevention and control of heavy metal input from a shipyard is required.

Analyzing the relationship between employee characteristics and performance in call center organizations: integration of social network analysis and repertory grid technique (조직 내 사회적 특성과 개인적 특성이 콜센터 업무 성과에 미치는 영향 분석: 사회연결망과 RGT를 중심으로 한 A사 사례 연구)

  • Kim, Jongmyoung;Geum, Youngjung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.5
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    • pp.466-475
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    • 2020
  • Current performance evaluation of call center employees is dependent on the number of calls they have resolved, regardless of the individual and social characteristics of employees. However, since call center tasks are highly customer-oriented and emotional laborious, individual capability as well as social characteristics of employees is critical to performance. Therefore, this study analyzed the relationship between employees' individual/social characteristics and their performance. To extract individual characteristics, a repertory grid technique was employed, whereas social network analysis was conducted to extract the social characteristics of employees. Using individual and social characteristics as input variables, multiple regression was conducted to analyze the effect of each variable on performance. As a result, in-degree centrality of dining network, initiative characteristics, open characteristics, and enjoyment of studying were determined to be important variables for performance. This study is expected to be used in both performance management and human resource management of call center practices.

A Study on the Improvements of the Speech Quality by using Distribution Characteristics of LSP parameters in the EVRC(Enhanced Variable Rate Codec) (LSP 파라미터의 분포특성을 이용한 EVRC의 음질개선에 관한 연구)

  • Min, So-Yeon;Na, Deok-Su
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.12
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    • pp.5843-5848
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    • 2011
  • To improve the efficiency of the channel spectrum and to reduce the power consumption of the system in EVRC, the voice signal is compressed and transmitted only when the user speaks to. In addition to this, voice frames are divided into three rates 1, 1/2 and 1/8 and each frame is handled differently. For example, we assumed that the input is silence region if the 1/8 rate is used. In this paper, the sections are firstly separated into the voiced speech signal region, unvoiced speech signal region, and silence region by using distribution characteristics of LSP parameters. Then the paper suggested to encode 1 rate for the voiced speech signal, 1/2 rate for the unvoiced speech signal region, 1/8 rate for the silence region. In other words, traditional way of transmission is used when sending full rate in the EVRC. However, when sending half rate, the voice is firstly distinguished between voiced and unvoiced. If the voice is distinguished as voiced, voice is converted into full rate before the transmission. If it is distinguished as silence, EVRC's basic rate is applied. In the experimental results with SNR, ASDM, transmission bit rate measurement, we have demonstrated that voice quality was improved by using the proposed algorithm.