• Title/Summary/Keyword: marginal cost

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Study on the Establishment of Barley Cultivation System using the Power Tiller (동력경운기를 중심으로한 맥류재배의 기계화 -관작업체계 확립에 관한 연구)

  • 이영렬;최규홍
    • Journal of Biosystems Engineering
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    • v.3 no.2
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    • pp.22-33
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    • 1978
  • To maintain the self-sufficiency of food production , it is required to improved the productivity and increase the effective utilization of land in the double cropping areas using improved cultivation technology. The following reasons encourage this cours of action because the overlapping rice harvest and barely seeding seasons complete for labour, the lower price of barley makes it financially less attractive to grow and these two facts together are responsible for a decrease in barley being planted in certain more seasonably marginal double cropping areas. Fro these reasons, it is desirable to carry out tests to improve the current cultivation techniques . In this interest , the following studies were carried out in the experimental field located at Banweol-myeon, Whasung-jkun, Gyeonggi-do from October 1977 to July 1978 in order to establish the mechanical method of barley cultivation using the power tiller. The summarized results are as follows. 1. The work performance in the seeding operation using the rotary barley seeder was 68 minutes per 10 ares which compares favourably with 408 min/10a using the conventional method. This is only one sixth of the time required by th conventional method. The operating costs using the rotary barley seeder was 1, 463 won per 10 areas as against 3, 486 Won per 10 ares for the conventional method, showing a saving of about 50% in comparison with the conventional method. 2. In the manure spreading operation, the work performance was 25 min/10a for the manure spreading machine , compared to 1089 min/10a for the manual operations. This is about one fourth of the time required by the conventional method, The operating costs were 810 Won/10a for the machine and 857 Won/10a for the manual labour. This cost shows little advantage by the machine over the manual labor costs. The conventional method of manure spreading will continue pending decision which will develope and improve the machine.3. Work performance in the rolling operation using the barley rolIer was 30 min/lOa which compares favourably with 135 min/10a using conventional method. This was one fourth of the time required by the conventional method. The operating costs were 514 Won/103. for the machine and 1, 003 Won/lOa for manual labour. In the weed control operation, the work performance and operating costs were 45min/lOa, 1, 399won/10a for the herbcide application using the power sprayer, 1, 149min/10a 8, 541won/lOa for the conventional method respectively. This is 26 times higher efficiency in comparison to the conventional method. 4. In the harvesting operation using the reaper binder and tiller attachment, the work performance was 60min/lOa and represents a cost of 2, 039won/10a. The con\ulcornerventional method took 640min/10a at a cost of 4, 757won/lOa. The reaper binder showns a saving of one tenth over the conventional method. The automatic thresher is already recommended for the current situations, and is now being used. 5. From a comparison of the results of the above trials, the serial cultivation system using the attachment for the power tiller such as the rotary barley seeder is now to be recommended for the current barley cultivation system. It is also recommend from these results that the mechanized technology now available must be used to improve and maintain the increase in barley production. It is seen th1t this is the only course now avaihble to solve the peak seasonal requirements of labour needed for l11rvesting and seeding between rice and barley cultivation.

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Development of a Model for Calculating Road Congestion Toll with Sensitivity Analysis (민감도 분석을 이용한 도로 혼잡통행료 산정 모형 개발)

  • Kim, Byung-Kwan;Lim, Yong-Taek;Lim, Kang-Won
    • Journal of Korean Society of Transportation
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    • v.22 no.5
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    • pp.139-149
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    • 2004
  • As the expansion of road capacity has become impractical in many urban areas, congestion pricing has been widely considered as an effective method to reduce urban traffic congestion in recent years. The principal reason is that the congestion pricing may lead the user equilibrium (UE) flow pattern to system optimum (SO) pattern in road network. In the context of network equilibrium, the link tolls according to the marginal cost pricing principle can user an UE flow to a SO pattern. Thus, the pricing method offers an efficient tool for moving toward system optimal traffic conditions on the network. This paper proposes a continuous network design program (CNDP) in network equilibrium condition, in order to find optimal congestion toll for maximizing net economic benefit (NEB). The model could be formulated as a bi-level program with continuous variable(congestion toll) such that the upper level problem is for maximizing the NEB in elastic demand, while the lower level is for describing route choice of road users. The bi-level CNDP is intrinsically nonlinear, non-convex, and hence it might be difficult to solve. So, we suggest a heuristic solution algorithm, which adopt derivative information of link flow with respect to design parameter, or congestion toll. Two example networks are used for test of the model proposed in the paper.

Estimation of Relative Economic Weights of Hanwoo Carcass Traits Based on Carcass Market Price

  • Choy, Yun-Ho;Park, Byoung-Ho;Choi, Tae-Jung;Choi, Jae-Gwan;Cho, Kwang-Hyun;Lee, Seung-Soo;Choi, You-Lim;Koh, Kyung-Chul;Kim, Hyo-Sun
    • Asian-Australasian Journal of Animal Sciences
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    • v.25 no.12
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    • pp.1667-1673
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    • 2012
  • The objective of this study was to estimate economic weights of Hanwoo carcass traits that can be used to build economic selection indexes for selection of seedstocks. Data from carcass measures for determining beef yield and quality grades were collected and provided by the Korean Institute for Animal Products Quality Evaluation (KAPE). Out of 1,556,971 records, 476,430 records collected from 13 abattoirs from 2008 to 2010 after deletion of outlying observations were used to estimate relative economic weights of bid price per kg carcass weight on cold carcass weight (CW), eye muscle area (EMA), backfat thickness (BF) and marbling score (MS) and the phenotypic relationships among component traits. Price of carcass tended to increase linearly as yield grades or quality grades, in marginal or in combination, increased. Partial regression coefficients for MS, EMA, BF, and for CW in original scales were +948.5 won/score, +27.3 $won/cm^2$, -95.2 won/mm and +7.3 won/kg when all three sex categories were taken into account. Among four grade determining traits, relative economic weight of MS was the greatest. Variations in partial regression coefficients by sex categories were great but the trends in relative weights for each carcass measures were similar. Relative economic weights of four traits in integer values when standardized measures were fit into covariance model were +4:+1:-1:+1 for MS:EMA:BF:CW. Further research is required to account for the cost of production per unit carcass weight or per unit production under different economic situations.

A Study on the Preferences for Food Intake of Korean Industrial Workers (한국 근로자의 식품섭취 기호도에 관한 연구)

  • Kim, Chang-Sook;Ahn, Myung-Soo
    • Journal of the Korean Society of Food Culture
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    • v.8 no.1
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    • pp.1-9
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    • 1993
  • This study was carried on the preferences for food intake pattern of Korean industrial workers. The survey was conducted from Feb 17, to March 31, 1992 by questionnaires which was composed of 21 items. The subjects of this study were composed of 426 clerical workers, and 439 physical workers. The results were obtained as follows. 1. In the educational background, clerical workers was almost of highschool or collage graduates, and physical workers was almost of highschool graduates. Marginal food cost of per person for lunch a day was from 500 Won to 1,000 Won. They replied that amount of staple food and side dishes were appropriate, and the type of preferable foods was Korean style cooked rice. Also it was known that physical workers thought their nutritive condition more badly than that of clerical workers. So the physical workers considered their health very much when they had meal. It was represented that unbalanced diet, without diet and drinking alcohol effected badly to food intake and taste of food was the most important point in food intake. 2. Preferences for staple foods; Cooked rice was preferred the most by the subjects. Cooked rice with redbean was preferred by clerical workers and cooked rice with soybean was preferred by physical workers and cooked rice with soybean was preferred by physical workers. Also clerical and physical workers liked Kalkooksoo (hot noodle), Nangmyun (cold noodle), bread, vegetable bread and disliked Sphagetti, Ramyun (Instant noodle) in same rate. In the next, cooked rice covered with raw fish pieces (Sushi) was preferred by clerical workers and Mandu-kook was preferred by physical workers. Also they disliked Curriedrice and Hashrice in same pattern. 3. Preference for side-dishes; The Acceptances for side-dishes were high soybean paste soup (clerical workers:43.7%, physical workers:34.4%), Kim chi stew, fried potatoes, crab steaming (37.8%, 36.9%), broiled fish (34.6%, 33.9%), fried green pepper, Ham, Chinese cabbage Kim chi, and pickled garlic by clerical and physical workers all together. But in clerical workers, Wooghugi beef-rib tang, Deodeok muchim, spinach namul, beef jangjeorim, fried shrimp were shown to have high preference in physical workers, beef-rib tang, wild onion and shepherd's purses muchim, soybean sprout, fish jeorim, fried sweet potatoes were high preference. 4. Preference of Snacks; The preferences for snacks were high in strawberry (clerical:36.3%, physical:34.3%), milk (49.9%, 44.4%), waxy rice Doek (30.7%, 30.2%), coffee (40.1%, 38.9%) by two groups in same order.

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Spatial Correlation Based Fast Coding Depth Decision and Reference Frame Selection in HEVC (HEVC의 공간적 상관성 기반 고속 부호화 깊이 및 참조영상 결정 방법)

  • Lee, Sang-Yong;Kim, Dong-Hyun;Kim, Jae-Gon;Choi, Hae-Chul;Kim, Jin-Soo;Choi, Jin-Soo
    • Journal of Broadcast Engineering
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    • v.17 no.5
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    • pp.716-724
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    • 2012
  • In this paper, we propose a fast decision method of maximum coding depth decision and reference frame selection in HEVC. To reduce computational complexity and encoding time of HEVC, two methods are proposed. In the first method, the maximum depth of each coding unit (CU) in a largest CU (LCU) is constrained by using the maximum coding depth used by adjacent LCUs based on the assumption that the spatial correlation is very high and rate-distortion (R-D) cost. And we constrain the number of reference pictures for prediction unit (PU) performing motion estimation by using the motion information of the upper depth PU. The proposed methods reduce computational complexity of the HEVC encoder by constraining the maximum coding depth and the reference frame. We could achieve about 39% computational complexity reduction with marginal bitrate increase of 1.2% in the comparison with HM6.1 HEVC reference software.

Study on CsRCI2D and CsRCI2H for improvement of abiotic stress tolerance in Camelina sativa L.

  • Lim, Hyun-Gyu;Kim, Hyun-Sung;Kim, Jung-Eun;Ahn, Sung-Ju
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.196-196
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    • 2017
  • Oilseed crop Camelina (Camelina sativa L.) is a suitable for biodiesel production that has high adaptability under low-nutrient condition like marginal land and requires low-input cost for cultivation. Enhanced abiotic stress tolerance of Camelina is very important for oil production under the wide range of different climate. CsRCI2s (Rare Cold Inducible 2) are related proteins in various abiotic stresses that predicted to localized at plasma membrane (PM) and endoplasmic reticulum (ER). These proteins are consist of eight-family that can be divided into tail (CsRCI2D/E/F/G) and no-tail (CsRCI2A/B/E/H) type of C-terminal. However, it is still less understood the function of C-terminal tail. In this study, CsRCI2D/H genes were cloned through gateway cloning system that used pCB302-3 as destination vector. And we used agrobacterium-mediated transformation system for generation of overexpression (OX) transformants. Overexpression of target gene was confirmed using RT-PCR and segregation ratio on selection media. We analyzed physiological response in media and soil under abiotic stresses using CsRCI2D and CsRCI2H overexpression plant. To compare abiotic stresses tolerance, wild type and CsRCI2D/H OX line seeds were sown on agar plate treated with various NaCl and mannitol concentration for 7 days. In the test of growth rate under abiotic stress on media, CsRCI2H OX line showed similar to NaCl and mannitol stress. In the other hand, CsRCI2D OX line showed to be improved stress tolerance that especially increased in 200mM NaCl but was similar on mannitol media. In greenhouse, WT and CsRCI2D/H OX lines for physiological analysis and productivity under abiotic stresses were treated 100, 150, 200mM NaCl. Then it was measured various parameters such as leaf width and length, plant height, total seed weight, flower number, seed number. CsRCI2H OX line in greenhouse did not show any changes in physiological parameters but CsRCI2D OX line was improved both physiological response and productivity under NaCl stress. Among physiological parameters of CsRCI2D OX line under NaCl stress, leaf length and width were observed shorter than WT but it were slightly longer than WT in 200mM NaCl stress. Furthermore, total seed weight of CsRCI2D OX line under stress displayed to decrease than WT in normal condition, but it was gradually raised with increasing NaCl stress then more than WT relatively. These results suggested CsRCI2D might be contribute to improve abiotic stress tolerance. However, function of CsRCI2H is need to more detail study. In conclusion, overexpression of CsRCI2s family can generate various environmental stress tolerance plant and may improve crop productivity for bio-energy production.

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Yield and Chemical Composition of Cassava Foliage and Tuber Yield as Influenced by Harvesting Height and Cutting Interval

  • Khang, Duong Nguyen;Wiktorsson, Hans;Preston, Thomas R.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.7
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    • pp.1029-1035
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    • 2005
  • A 3${\times}$4 factorial field experiment with a complete randomised split-plot design with four replicates was conducted from June 2002 to March 2003 at the experimental farm of the Nong Lam University, Ho Chi Minh City, Vietnam, to determine effects of different harvesting heights (10, 30 and 50 cm above the ground) and cutting intervals (45, 60, 90 and 285 days) on yield of foliage and tubers, and chemical composition of the foliage. Cassava of the variety KM 94 grown in plots of 5 m${\times}$10 m at a planting distance of 30 cm${\times}$50 cm was hand-harvested according to respective treatments, starting 105 days after planting. Foliage from the control treatment (285 days) and all tubers were only harvested at the final harvest 285 days after planting. Dry matter and crude protein foliage yields increased in all treatments compared to the control. Mean foliage dry matter (DM) and crude protein (CP) yields were 4.57, 3.53, 2.49, and 0.64 tonnes DM $ha^{-1}$ and 939, 684, 495 and 123 kg CP $ha^{-1}$ with 45, 60, 90 and 285 day cutting intervals, respectively. At harvesting heights of 10, 30 and 50 cm the DM yields were 4.27, 3.67 and 2.65 tonnes $ha^{-1}$ and the CP yields were 810, 745 and 564 kg $ha^{-1}$, respectively. The leaf DM proportion was high, ranging from 47 to 65%. The proportion of leaf and petiole increased and the stem decreased with increasing harvesting heights and decreasing cutting intervals. Crude protein content in cassava foliage ranged from 17.7 to 22.6% and was affected by harvesting height and cutting interval. The ADF and NDF contents of foliage varied between 22.6 and 30.2%, and 34.2 and 41.2% of DM, respectively. The fresh tuber yield in the control treatment was 34.5 tonnes $ha^{-1}$. Cutting interval and harvesting height had significant negative effects on tuber yield. The most extreme effect was for the frequent foliage harvesting at 10 cm harvesting height, which reduced the tuber yield by 72%, while the 90 day cutting intervals and 50 cm harvesting height only reduced the yield by 7%. The mean fresh tuber yield decreased by 56, 45 and 27% in total when the foliage was harvested at 45, 60 and 90 day cutting intervals, respectively. It is concluded that the clear effects on quantity and quality of foliage and the effect on tuber yield allow alternative foliage harvesting principles depending on the need of fodder for animals, value of tubers and harvesting cost. An initial foliage harvest 105 days after planting and later harvests with 90 days intervals at 50 cm harvesting height increased the foliage DM and CP yield threefold, but showed only marginal negative effect on tuber yield.

Marker Assisted Selection-Applications and Evaluation for Commercial Poultry Breeding

  • Sodhi, Simrinder Singh;Jeong, Dong Kee;Sharma, Neelesh;Lee, Jun Heon;Kim, Jeong Hyun;Kim, Sung Hoon;Kim, Sung Woo;Oh, Sung Jong
    • Korean Journal of Poultry Science
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    • v.40 no.3
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    • pp.223-234
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    • 2013
  • Poultry industry is abounding day by day as it engrosses less cost of investment per bird as compared to large animals. Poultry have the most copious genomic tool box amongst domestic animals for the detection of quantitative trait loci (QTL) and marker assisted selection (MAS). Use of multiple markers and least square techniques for mapping of QTL affecting quality and production traits in poultry is in vogue. Examples of genetic tests that are available to or used in industry programs are documented and classified into causative mutations (direct markers), linked markers in population-wide linkage disequilibrium (LD) with the QTL (LD markers), and linked markers in population wide equilibrium with the QTL (LE markers). Development of genome-wide SNP assays, role of 42 K, 60 K (Illumina) and 600 K (Affymetrix$^{(R)}$ Axim$^{(R)}$) SNP chip with next generation sequencing for identification of single nucleotide polymorphism (SNP) has been documented. Hybridization based, PCR based, DNA chip and sequencing based are the major segments of DNA markers which help in conducting of MAS in poultry. Economic index-marker assisted selection (EI-MAS) provides platform for simultaneous selection for production traits while giving due weightage to their marginal economic values by calculating predicted breeding value, using information on DNA markers which are normally associated with relevant QTL. Understanding of linkage equilibrium, linkage dis-equilibrium, relation between the markers and gene of interest are quite important for success of MAS. This kind of selection is the most useful tool in enhancing disease resistance by identifying candidate genes to improve the immune response. The application of marker assisted selection in selection procedures would help in improvement of economic traits in poultry.

Real Option Study on Cookstove Offset Project under Emission Allowance Price Uncertainty (배출권 가격 불확실성을 고려한 고효율 쿡스토브 보급사업 실물옵션 연구)

  • Lee, Jaehyung
    • Environmental and Resource Economics Review
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    • v.29 no.2
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    • pp.219-246
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    • 2020
  • From the Phase II (2018~2020) of K-ETS, the offset credit from 'CDM projects that domestic companies and others have carried out in foreign countries' can be used in the K-ETS. As a result, stakeholders in the K-ETS market are actively developing overseas CDM projects, such as the 'high-efficiency cook stove project'. which can secure a large amount of credits while marginal cost is relatively low. This paper develops the investment decision-making model of offset project for the 'high-efficiency cook stove project' using the real option approach. Under the uncertainty of the emission allowance price, the optimal investment threshold (p) is derived and sensitivity analysis is conducted. As a result, in the standard scenario (PoA-S), the optimal investment threshold is 29,054won/ton, which is lower than the stock price (pspot). However, allocation entities are not only economics in the CDM project, but also CDM risk factors such as non-renewable biomass ratio, cook stove replacement ratio, equity ratio with host country, investment period and submission limitation of emission allowance. In addition, offset project developers will be able to derive the optimal investment threshold for each business stage and use it for economic feasibility checks.

Effect of Coating System to Prevent the Deterioration of Concrete Subjected to Compressive Stress (압축응력이 인가된 콘크리트의 열화제어를 위한 표면도막공법의 효과)

  • Yoon, In-Seok
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.16 no.3
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    • pp.23-30
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    • 2012
  • For cracked concrete, it is obvious that cracks should be preferential channel for the penetration of aggressive substances such as chloride ions according to the previous researches. In order to extend the lifetime of cracked concrete, critical issues in the performance of the concrete is the risk of chloride-induced corrosion. Even though crack width can be reduced due to the high reinforcement ratio, the question is to which extend these cracks may jeopardize the durability of cracked concrete. If the size of crack is small, surface treatment system can be considered as one of the best options to extend the service life of concrete structures exposed to marine environment simply in terms of cost effectiveness versus durability performance. Thus, it should be decided to undertake an experimental study on the effect of surface coating system, which can be able to seal the concrete and the cracks to aggressive substances-induced corrosion in particular. In this study, it is excuted to examine the effect of surfaced treated systems on chloride penetration and carbonation through compressive stress induced cracks. Experimental results have showed conclusively that critical stress linked with deterioration, should be existed in compressive stress ratio 50 ~ 70% for chloride penetration and 70 ~ 80% for carbonation, respectively. When the critical stress is exceeded in concrete, a comparatively large deterioration was measured where the critical stress in concrete, the increase in the mass transportation is marginal in spite of the large increase in micro-cracks. As for the effect of surface coating system on crack-sealing, it can be seen conclusively that cracks can be healed.