• 제목/요약/키워드: Loss

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Prediction of Soil Loss in Watershed using Universal Soil Loss Equation and Geo-Spatial Information System (지형공간정보체계와 범용토양유실방정식을 이용한 유역의 토양유실 예측)

  • Yang, In-Tae;Shin, Ke-Jong;Kim, Dong-Moon;Yu, Young-Geol
    • Journal of Industrial Technology
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    • v.19
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    • pp.147-154
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    • 1999
  • The soil loss by rainfalls or runoffs has been one of the main environment problems in 20th century. The soil loss cause the various problems those are decreasing of the agricultural productivity, desolating of pasture land and disturbing of water flowing. Therefore, it is very important to measure properly various factors those are affecting to soil loss and to recognize a seriousness of soil loss problem. In this study, we use the USLE(Universal Soil Loss Equation) as a basic approaching way for soil loss analysis in a watershed, and the GSIS(Geo-Spatial Information System) technique is applied to evaluate for factors those are related to the USLE. The results of this study are consisted of three parts those are to build up the various topographical information that is needed for analysis of wide area soil loss by using the USLE, to evaluate the factors those are needed to the USLE, to estimate the soil loss condition of subbasin in the watershed.

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Explaining Share of Farm Loss Systemic with County Loss in the United States?

  • Kim, Sang-Hyo;Lim, Jin-Soon;Zulauf, Carl
    • Journal of Distribution Science
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    • v.15 no.11
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    • pp.21-29
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    • 2017
  • Purpose - Relationship between farm and county losses determines whether the county program provides too little, too much, or similar amount of assistance relative to the loss on an individual farm. A review of the literature finds limited analysis of the determinants of this relationship. This paper conducts such an analysis using farm-level yield data. Research design, data, and methodology - Farm-level yield data from Illinois and Kansas farm business management associations are used for to calculate the correlation between farm and county loss and the share of farm loss systemic with county loss, and also for the regression analysis. Results - Average share of farm loss systemic with the county loss lies between 42% and 68%. The correlation between farm and county yield/revenue deviation from expected value is statistically significant in all four models. The coefficient is positive, implying the higher the correlation, the larger the share of farm loss that is systemic with the county loss. Conclusions - The findings of this study are consistent with the existing literature which argues that county variability may not be closely associated with farm variability. The findings of this study thus raise questions about the efficacy of area yield and revenue insurance products in helping farmers manage their risk.

A Study on the Optimal Method of Loss Calculation in Distribution System (배전계통에 있어서 최적 손실산정 기법에 관한 연구)

  • 김미영;노대석;황혜미;김광호;신성수;김재언
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.53 no.6
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    • pp.340-349
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    • 2004
  • Recently, the needs and concerns for the power loss are increasing according to the energy conservation at the level of the national policies and power utilities's business strategies. Especially, the issue of the power loss is the main factor for the determining the electric pricing rates in the circumstances of the deregulation of electrical industry. However, because of the lacking of management for power loss load factors (LLF), it is difficult to make a calculation for the power loss and to make a decision for the electric rates. And loss factor(k-factor), which is a most important factor for calculation of the distribution power loss, has been used as a fixed value of 0.32 since the fiscal year 1973. Therefore, This study presents the statistical calculation methods of the loss factors classified by load types and seasons by using the practical data of 65 primary feeders which are selected by proper procedures. Based on the above the algorithms and methods, the optimal method of the distribution loss management classified by facilities such as primary feeders, distribution transformers and secondary feeders is presented. The simulation results show the effectiveness and usefulness of the proposed methods.

Effects of the Inlet Boundary Layer Thickness on the Loss Mechanism in an Axial Compressor (입구 경계층 두께가 축류 압축기 손실에 미치는 영향)

  • Choi, Minsuk;Baek, Jehyun
    • 유체기계공업학회:학술대회논문집
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    • 2004.12a
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    • pp.419-426
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    • 2004
  • A three-dimensional computation was conducted to understand effects of the inlet boundary layer thickness on the loss mechanism in a low-speed axial compressor operating at the design condition(${\phi}=85\%$) and near stall condition(${\phi}=65\%$). At the design condition, the flow phenomena such as the tip leakage flow and hub comer stall are similar independent of the inlet boundary layer thickness. However, when the axial compressor is operating at the near stall condition, the large separation on the suction surface near the casing is induced by the tip leakage flow and the boundary layer on the blade for thin inlet boundary layer but the hub corner stall is enlarged for thick inlet boundary layer. These differences of internal flows induced by change of the boundary layer thickness on the casing and hub enable loss distributions of total pressure to be altered. When the axial compressor has thin inlet boundary layer, the total pressure loss is increased at regions near both casing and tip but decreased in the core flow region. In order to analyze effects of inlet boundary layer thickness on total loss in detail, using Denton's loss models, total loss is scrutinized through three major loss categories in a subsonic axial compressor such as profile loss, tip leakage loss and endwall loss.

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Optimal Calculation Method of Distribution Loss in Distribution Systems

  • Rho Dae-Seok
    • KIEE International Transactions on Power Engineering
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    • v.5A no.2
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    • pp.109-115
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    • 2005
  • Recently, the needs and concerns regarding power loss have been increasing according to energy conservation at the level of the national policies and the business strategies of power utilities. In particular, the issue of power loss is the main factor for determining rates for electrical consumption in the deregulation of the electrical industry. However, because of the lack of management for power loss load factors (LLF) it is difficult to make a calculation for power loss and to make a decision concerning the electric rates. Furthermore, loss factor (k-factor) in Korea, which is of primary significance in the calculation of distribution power loss, has been used as a fixed value of 0.32 since the fiscal year 1973. Therefore, this study presents the statistical calculation methods of the loss factors classified by load types and seasons by using the practical data of 65 primary feeders that have been selected by appropriate procedures. Based on the above, the algorithms and methods, as well as the optimal method of the distribution loss management classified by facilities such as primary feeders, distribution transformers and secondary feeders is presented. The simulation results demonstrate the effectiveness and usefulness of the proposed methods.

Decision of Producer's Specification Limits Considering Types of Loss Function (손실함수의 형태를 고려한 생산자 규격한계의 결정)

  • Kim, Dong-Hyuk;Chung, Young-Bae
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.41 no.3
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    • pp.145-153
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    • 2018
  • Taguchi regarded the concept of quality as 'total loss to society due to fluctuations in quality characteristics from the time of supplied to the customer.' The loss function is a representative tool that can quantitatively convert the loss that occurs due to the deviation of the quality characteristic value from the target value. This has been utilized in various studies with the advantage that it can change the social loss caused by fluctuation of quality characteristics to economic cost. The loss function has also been used extensively in the study of producer specification limits. However, in previous studies, only the second order loss function of Taguchi is used. Therefore, various types of losses that can occur in the process can't be considered. In this study, we divide the types of losses that can occur in the process considering the first and second loss functions and the Spiring's reflected normal loss function, and perform total inspection before delivering the customer to determine the optimal producer specification limit that minimizes the total cost. Also, we will divide the quality policy for the products beyond the specification limits into two. In addition, we will show the illustration of expected loss cost change of each model according to the change of major condition such as customer specifications and maximum loss cost.

The Study on the Weight loss Finishing for the Mixture of Silk/Polyester I. The Weight loss Finishing for the Raw-silk/Polyester (Silk/Polyester 혼섬유 재료의 감량가공에 관한 연구 I. Raw-silk/Polyester 혼섬유의 감량가공)

  • 배도규
    • Journal of Sericultural and Entomological Science
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    • v.35 no.2
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    • pp.114-119
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    • 1993
  • The weight loss for the mixture(raw-silk/PET) was tested to investigate the effects of weight loss accelerator on the degumming and weight loss. The degumming loss of raw-silk was decreased while the weight loss polyester(PET) was increased depending on the increase of accelerator concentration. The difference of the weight loss was not significant in raw-silk but the weight loss of PET was increased with the increase of the alkali concentration. The proper degumming of raw-silk was obtained and simultaneously the weight loss of PET was high for the raw-silk/PET "A" and "B" type. The proper degumming of raw-silk was obtained but the weight loss of PET was low for the raw-silk/PET "D" and "E" type. It showed that the typical degumming curve in raw-silk part and the weight loss of PET was increased depending on the treatment time in the weight loss for the fabric composed of raw-silk and PET.

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A hybrid model of regional path loss of wireless signals through the wall

  • Xi, Guangyong;Lin, Shizhen;Zou, Dongyao
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.16 no.9
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    • pp.3194-3210
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    • 2022
  • Wall obstruction is the main factor leading to the non-line of sight (NLoS) error of indoor localization based on received signal strength indicator (RSSI). Modeling and correcting the path loss of the signals through the wall will improve the accuracy of RSSI localization. Based on electromagnetic wave propagation theory, the reflection and transmission process of wireless signals propagation through the wall is analyzed. The path loss of signals through wall is deduced based on power loss and RSSI definition, and the theoretical model of path loss of signals through wall is proposed. In view of electromagnetic characteristic parameters of the theoretical model usually cannot be accurately obtained, the statistical model of NLoS error caused by the signals through the wall is presented based on the log-distance path loss model to solve the parameters. Combining the statistical model and theoretical model, a hybrid model of path loss of signals through wall is proposed. Based on the empirical values of electromagnetic characteristic parameters of the concrete wall, the effect of each electromagnetic characteristic parameters on path loss is analyzed, and the theoretical model of regional path loss of signals through the wall is established. The statistical model and hybrid model of regional path loss of signals through wall are established by RSSI observation experiments, respectively. The hybrid model can solve the problem of path loss when the material of wall is unknown. The results show that the hybrid model can better express the actual trend of the regional path loss and maintain the pass loss continuity of adjacent areas. The validity of the hybrid model is verified by inverse computation of the RSSI of the extended region, and the calculated RSSI is basically consistent with the measured RSSI. The hybrid model can be used to forecast regional path loss of signals through the wall.

Basic Simulation for Vuilleumier Cycle Heat Pump (VM사이클 히트펌프 기초 설계프로그램)

  • Park, Byung-Duck
    • Journal of the Korean Society of Industry Convergence
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    • v.3 no.3
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    • pp.265-273
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    • 2000
  • Basic simulation program for Vuilleumier cycle heat pump was developed that can use precise VMHP design and analysis. VMHP system was divided 11 sections in simulation. Simulation was used adiabatic model analysis and that considered with heat transfer performance for heat exchanger, regenerator loss, conduction loss, shuttle loss, pumping loss and pressure loss by flow friction. Specially, friction loss of connection pipe between heat compression side and heat pump side, leakage of rod seal and piston seal was considered in the analysis.

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Case of improvement of hair loss using Ortho-Cellular Nutrition Therapy (OCNT) (세포교정영양요법(OCNT)을 이용한 탈모 개선 사례)

  • Yeon Choi
    • CELLMED
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    • v.14 no.3
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    • pp.70.1-70.3
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    • 2024
  • Objective: Report of a case of improvement of hair loss through the use of OCNT. Methods: A 60-year old Korean male has been suffering from hair loss. Results: Hair loss was markedly improved following implementation of OCNT. Conclusion: Application of OCNT to hair loss can be helpful in alleviation of the symptoms.