• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 춘계학술대회 논문집
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• pp.187-190
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• 2009

Recently, automotive companies have invested in vehicle weight reduction and clean car development because of oil price rises and environmental problems. In particular, USA car makers have developed the vehicle spending 1 liter per 34km complying with PNGV(Partnership for a new generation of vehicle) and Europe car makers have developed the vehicle spending 3 liters per 100km. The USA government announced "The green car policy" in order to boost production of more fuel effective cars in 2009. According to the policy, it will be restricted to sell the car which spends more than 1 liter per 14.9km by 2020. To satisfy the current situations on automotive market, hydroforming technology has widely adapted vehicle structures such as engine cradle, chassis frame, A pillar, radiator support, etc. However, automotive companies have to consider formability and performance to improve and maximize the benefit from this technology in advance of detail design. The paper deals with one of the vehicle weight reduction methods using tube hydroforming technology and platform commonality in front suspension. FEA simulation is also introduced to evaluate hydro-formability and NVH performance at the beginning of design stage which is the best way to reduce the failure cost.

• Journal of Animal Science and Technology
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• 제57권6호
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• pp.21.1-21.8
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• 2015

The digestibility of different vegetable protein sources were investigated and the effects of supplementing canola meal (CM) as partial inclusions were studied in growing pigs, to determine the performance parameters and its economic importance. In Exp. 1, four pigs (average initial $BW=15.4{\pm}0.35kg$, 5 weeks of age) fitted with simple T-cannula at terminal ileum, were fed four diets following repeated $4{\times}4$ Latin square design having adoption period of 7 days. Diet 1 was Nitrogen free diet containing corn starch. Diets 2, 3, and 4 were the basal diet supplemented with soybean meal (SBM), rapeseed meal (RSM), and domestic CM respectively. The AID of crude protein was decrease in RSM in comparison to SBM supplementation. The AID of Dietary indispensable amino acids (DIAA) such as Lys, Meth, Pha, and dispensable amino acid Ala, Pro, Asp were decreased (P < 0.05) in RSM supplemented diets. The SID of DIAA does not differ but the SID of Asp was higher (P < 0.05) in RSM and CM diets while SID of Pro was lower (P < 0.05) in RSM in comparison to SBM supplemented diets. In Exp. 2, 192 growing pigs (average initial BW $24.76{\pm}2.55kg$) were randomly allotted to four dietary treatments with increasing levels of CM i.e. 0, 3.75, 7.50, and 11.25 % respectively. Diets were fed in meal form for 35 days. Increasing CM levels in diets had no effects (P > 0.05) on growth performance and apparent total tract digestibility (ATTD) of nutrients and energy. Total weight gain, total feed intake, and feed cost per kg weight gain were not affected by increasing levels of CM in diets but total feed cost (TFC) per pigs was linearly reduced (26.463 to 25.674; P < 0.05). Broadly, the AID, and SID of amino acid was reduced in RSM but was not effected in CM in comparison to SBM supplemented pigs. Moreover, increasing levels of CM in pigs diet had no effect on the ATTD and performance but TFC per pig was reduced. Thus CM inclusion of up to 11.25 % in diets can be used for reducing the production cost in growing pigs without any negative effect.

• 보건행정학회지
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• 제26권2호
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• pp.107-114
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• 2016

Background: Over the last few decades, because hospitals in South Korea also have undergone dramatic changes, Korean hospitals traditionally have provided specialized health care services in the health care market. Inner Herfindahl-Hirschman Index (IHI) measures hospital caseloads based on patient proportions, independent of patient volumes. However, IHI that rely solely on patient proportions might be problematic for larger hospitals that provide a high number of diagnosis categories, as the patient proportions in each category are naturally relatively smaller in such hospitals. Therefore, recently developed novel measure, category medical specialization (CMS) is based on patient volumes as well as patient proportions. Methods: We examine the distribution of hospital specialization score by hospital size and investigate association between each hospital specialization and length of stay per case and hospital cost per case using Korean National Health Insurance Service-cohort sample data from 2002 to 2013. Results: Our results show that IHI show a decreasing trend according to the number of beds and hospital type but CMS show an increasing trend according to the number of beds and hospital type. Further, inpatients admitted at hospitals with higher IHI and CMS had a shorter length of stay per case (IHI: B=-0.104, p<0.0001; CMS: B=-0.044, p=0.001) and inpatients admitted at hospitals with higher IHI and CMS had a shorter hospital cost per case (IHI: B=-0.110, p=0.002; CMS: B=-0.118, p=<0.0001). Conclusion: This study may help hospital policymakers and hospital administrators to understand the effects of hospital specialization strategy on hospital performance under recent changes in the Korean health care environment.

• 전기학회논문지P
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• 제58권3호
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• pp.303-309
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• 2009

Switched Reluctance Motor(SRM) has become popular for industrial application, particularly for low medium drives due to the advantages of SRM over the other ac motors: SRM can be manufactured with low cost because it has a simple structure. But, asymmetric bridge converter that generally is used for driving requires two discrete switching devices and freewheeling diodes per phase, and cause the SRM drives to be complicated and to increase the cost of overall system. Therefore, this paper suggests a new type of 4-switch converter for SRM. 4-switch converter topology is studied to provide a possibility for the realization of low cost 3-phase SRM drive system. For effective utilization of the developed system, a new current control algorithm is designed and implemented to produce the desired dynamic performance. With the developed power conversion circuit and control scheme, it is expected that the proposed system can be widely used in commercial applications with reduced system cost.

• 한국건축시공학회지
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• 제10권2호
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• pp.97-104
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• 2010

본 연구에서는 전열해석 프로그램인 피지벨(PHYSIBEL)을 사용하여 블라인드 내장형 창호시스템의 일사차단성능 및 단열성능에 따른 에너지 성능을 평가하였다. 피지벨 해석시 창호별 구성 재료의 열적특성과 해석조건을 결정하기 위해서 Mock-up시험을 실시하였으며, 컴퓨터 시뮬레이션을 통한 결과를 바탕으로 공동주택 기준층 1개 세대(33평형)를 대상으로 연간에너지 소비특성, 연간전열량, 연간 냉난방 비용을 분석하였다. 실험결과, 연간전열량은 일반 창호시스템 대비 블라인드 내장형 창호시스템에서 블라인드를 올린 경우 냉방시 10%, 난방시 11% 절감할 수 있으며, 블라인드를 내린 경우 냉방시 25%, 난방시 30%정도를 절감할 수 있는 것으로 나타났다. 블라인드 내장형 창호시스템의 냉 난방 부하 절감량은 일반 창호시스템에 비해 냉방시 283.3KWh, 난방시 76.3KWh 로 냉 난방 에너지 절감효과는 단위세대당 359.6KWh 절감시킬 수 있는 것으로 나타났으며, 이것은 단위세대당 연간 에너지원단위(TOE) 약 0.078toe, 이산화탄소톤($tCO_2$) $0.16tCO_2$을 절감시킬 수 있어 온실가스 저감에도 유리할 것으로 판단된다. 또한, 블라인드 내장형 창호시스템의 냉 난방비용 절감액은 일반창호시스템과 비교하여 연간 냉방비용 10만원, 난방비용 5만원으로 연간 냉 난방 비용을 약 15만원 정도 절감시킬 수 있는 것으로 나타났다.

• 산업경영시스템학회지
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• 제42권4호
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• pp.145-152
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• 2019

All machines deteriorate in performance over time. The phenomenon that causes such performance degradation is called deterioration. Due to the deterioration, the process mean of the machine shifts, process variance increases due to the expansion of separate interval, and the failure rate of the machine increases. The maintenance model is a matter of determining the timing of preventive maintenance that minimizes the total cost per wear between the relation to the increasing production cost and the decreasing maintenance cost. The essential requirement of this model is that the preventive maintenance cost is less than the failure maintenance cost. In the process mean shift model, determining the resetting timing due to increasing production costs is the same as the maintenance model. In determining the timing of machine adjustments, there are two differences between the models. First, the process mean shift model excludes failure from the model. This model is limited to the period during the operation of the machine. Second, in the maintenance model, the production cost is set as a general function of the operating time. But in the process mean shift model, the production cost is set as a probability functions associated with the product. In the production system, the maintenance cost of the equipment and the production cost due to the non-confirming items and the quality loss cost are always occurring simultaneously. So it is reasonable that the failure and process mean shift should be dealt with at the same time in determining the maintenance time. This study proposes a model that integrates both of them. In order to reflect the actual production system more accurately, this integrated model includes the items of process variance function and the loss function according to wear level.

• Journal of Preventive Medicine and Public Health
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• 제39권2호
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• pp.149-158
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• 2006

Objectives : We wanted to evaluate the economic value of a pharmaceutical product, Kremezin, for treating patients with chronic renal failure (CRF) by estimating the amount of cost savings due to its effect for delaying the initiation of dialysis treatments. Methods : We defined a conventional treatment for CRF accompanied by Kremezin therapy as 'the treatment group' and only conventional treatment as 'the alternative group.' The types of costs included were direct medical and nonmedical costs and costs of productivity loss. The information on the effect of Kremezin was obtained from the results of earlier clinical studies. Cost information was derived from the administrative data for 20 hemodialysis and 20 peritoneal dialysis patients from one tertiary care hospital, and also from the administrative data of 10 hemodialysis patients from one free-standing dialysis center. Per-capita cost savings resulting from Kremezin therapy were separately estimated for the cases with delay for the onset of hemodialysis and the cases with immediate performance of peritoneal dialysis. By computing the weighted average for the cases of hemodialysis and peritoneal dialysis, the expected per-capita cost savings of a patient with CRF was obtained. Using a discount rate of 5%, future cost savings were converted to the present value. Results : The present value of cumulative cost savings per patient with CRF from the societal perspective would be $18,555,000{\sim}29,410,000$ Won or $72,104,000{\sim}112,523,000$ Won if Kremezin delays the initiation of dialysis by 1 or 4 years. Conclusions : The estimated amount of cost savings resulting from treating CRF patients with Kremezin confirms that its effect for delaying the onset of dialysis treatments has a considerable economic value.

• 대한건축학회논문집:구조계
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• 제34권3호
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• pp.43-52
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• 2018

This study is conducted to evaluate the performance of ceramic panels and painting materials for humidity control which are developed in non-plastic room temperature hardening structure as part of a project to improve a residential environment for the low-income class, rather than the performance of high-priced humidity control materials that are produced with the existing plasticity processing. The testing methods included the measurements of absorption & desoprtion of humidity per material; Mock-up Testing; an evaluation method of comparing the absorption & desoprtion performances of Ecocarat, ceramic panels and painting materials through Living Lab. According to the measurements of absorption & desoprtion per material, ceramic panels, E panel, and ceramic painting material showed 73.3g/m2, 96.6g/m2, and 111.1g/m2, respectively. That is, the performance of humidity control of each material was found to be good in the order of: Ceramic Paint > E panel > Ceramic Panel. According to performance evaluation testing with Mock-up test and Living Lab, Ceramic Paint, Ecocarat, and Ceramic Panels showed better absorption & desoprtion performances in the order.

• 품질경영학회지
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• 제44권4호
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• pp.751-770
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• 2016

Purpose: Two-stage ${\bar{X}}$ chart is a useful tool for process control when a surrogate variable may be used together with a performance variable. This paper extends the two-stage ${\bar{X}}$ chart to a three stage version by decomposing the first stage into the preliminary stage and the main stage. Methods: The expected cost function is derived using Markov-chain approach. The optimal designs are found for numerical examples using a genetic algorithm combined with a pattern search algorithm and compared to those of the two-stage ${\bar{X}}$ chart. Sensitivity analysis is performed to see the parameter effects. Results: The proposed design outperforms the optimal design of the two-stage ${\bar{X}}$ chart in terms of the expected cost per unit time unless the correlation between the performance and surrogate variables is modest and the shift in process mean is smallish. Conclusion: Three-stage ${\bar{X}}$ chart may be a useful alternative to the two-stage ${\bar{X}}$ chart especially when the correlation between the performance and surrogate variables is relatively high and the shift in process mean is on the small side.

• Journal of Animal Science and Technology
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• 제55권4호
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• pp.263-272
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• 2013

This experiment was conducted to investigate the effects of soybean meal (SBM) of different origin (Korea, India or Brazil) on performance, fecal microflora and economics of grower pigs. A total of 144 grower pigs (initial BW, 10.4 kg) were randomly allotted to six treatments on the basis of BW. Pig's diets containing SBM were formulated based on the total amino acid (TAA) or true ileal digestible amino acid (TIDAA) levels. Pigs fed domestic SBM diets had greater (p<0.05) overall ADG, ADFI and final body weight and apparent total tract digestibility (ATTD) of DM, GE and CP (phases I, II and III) than those fed diets containing SBM originated from India or Brazil. Moreover, greater (p<0.05) ADG, ADFI, feed /gain (F/G), and ATTD of DM, GE and CP were observed in response to diets formulated on a TIDDA basis when compared with those formulated on a TAA basis. The fecal microflora was not affected (p>0.05) by dietary treatments. The overall feed cost per kg body weight gain was less (p<0.05) for diets formulated using domestic SBM than for those containing SBM from India, while the feed cost per kg body weight gain was less (p<0.05) for diets formulated prepared on a TIDAA than a TAA basis. These results indicate that domestic SBM has better quality than SBM imported from Brazil or India and better performance was obtained when diets were formulated based on the true ileal digestible amino acid (TIDAA) content.