• 한국건축시공학회지
• /
• 제16권3호
• /
• pp.237-245
• /
• 2016

시공이음부 발생에 따른 초고성능 콘크리트의 일체성을 확보하기 위해서는 그 특성을 수반함과 동시에 전단부착성능에 대한 정량적인 계면처리방법이 필요할 것으로 판단된다. 이에, 본 연구는 초고성능 콘크리트 타설 시, 발생하는 시공이음부의 부착성능을 확보하기 위한 일환으로서 시공이음부 계면처리방법에 따른 전단부착성능 평가를 통하여 재료적인 측면에서의 합리적인 계면처리방법을 도출하고자 한다. 초고성능 콘크리트 배합은 180MPa의 배합강도를 사용하였으며, 계면처리방법으로는 MN, AC, GR-10-0, GR-20-0, GR-30-0, SH-30-5, SH-30-10으로써 총 7수준으로 설정하였다. 실험체는 $150{\times}150{\times}150mm$의 Size로 제작 후, 전단부착강도 평가를 위하여 Direct shear test를 실시하였다. 실험결과, 시공이음부 접합면에 대해 계면처리를 실시한 경우 부착성능이 향상되는 것을 확인하였으며, 접합부 단면적이 증가할수록 초고성능 콘크리트의 일체성 확보에 유리할 것으로 판단된다. 또한 콘크리트의 일체성을 확보하기 위해서는 접합면 단면적의 비율 및 요철의 깊이, 개수 등이 적절히 고려되어야 할 것으로 판단된다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제24권9호
• /
• pp.1268-1273
• /
• 2011

The present study was conducted to determine a feasible method of protein concentrate extraction from rice bran (RBPC) and its effect as a substitution for skim milk in early weaning pig diets. An investigation to extract protein concentrate from full fat rice bran was undertaken to determine the best ratio of water and rice bran, the amount of NaOH and a HCl solvent to use in a simple paddle-type mixer with modified spinning to produce RBPC. The results stated that the best ratio for water mixing in the RBPC extraction process was 1:5 with 20 g NaOH and 30 min in a paddle-type mixer at 300 rpm. A mix of 250 ml 0.2 N HCl was optimum for neutralization and protein precipitation. After the fluid was spun out with a washing machine, the sediment was left for 12-14 hours to complete the filtration. One kilogram of rice bran could produce an average of 324.5 gram RBPC and it contained 3.40% ash, 496.48 kcal of GE/100 gram, 1.94% crude fiber, 28.20% ether extract, 7.64% moisture and 16.66% crude protein, respectively. A total of 45 crossbred piglets, weaned at 3 weeks of age were allotted into control diet (A) and dietary treatments formulated with a four different rates of RBPC substitution for skim milk at a percentage of 25 (B), 50 (C), 77 (D) and 100 (E) respectively, in a randomized complete block (RCB) design. All piglets had free access to feed and water until 8 week of age when the experiment ended. Feed intake, average daily gain, growth rate and feed efficiency were not affected by dietary treatments. Blood test parameters after completion of the growth trial indicated normal health. Even though the mean of cell hemoglobin concentration was significantly different between treatments (p<0.05) it was still within the normal range. The cost difference for BW gain of 100% RBPC substituted for skim milk in the weaning diet was approximately 35% lower than that of the control and the relative cost of production was 96.67, 92.85, 70.75 and 64.48% lower for the replacement of 25, 50, 75 and 100% of skim milk respectively. These results implied that this technology is feasible for use by small scale farmers to improve their self-reliance.

• 산학경영연구
• /
• 제4권
• /
• pp.355-383
• /
• 1991

1. The Purpose of This study research: The focus of marketing until recently has simply been on sales which means the transfer of goods from the producer to the consumer and on profits therefrom. However, the excess supply of goods due to the expansion of the economy and the resulting fierce competition between companies have changed the nature of marketing. Maximizing consumers' satisfaction and establishing marketing mix strategies for market subdivision and penetration into the target market are now significant roles of the marketing manager. In addition, with regard to company management, information within the company which had been collected, managed and processed sporadically indegrated manner. The purpose of this research on marketing information systems in connection with the above will be to seek ways enabling us to create an efficient and integrated information system for an entire company. 2. The Method and Scop of This Stdudy: Marketing information systems, as a part of management information systems, shall be examined based on relevant theoretical literature. The research process shall be generally developed as follows: 1) The basic structure of the marketing information systems, including its fundamental purpose and necessity, shall be examined. 2) The method for a specific plan shall be presented through fundamental marketing strategy concepts and marketing decision-making. 3) A general model shall be presented based on examinations of various mod els used for marketing information systems and on research of the models' relationship with management information systems. 4) The direction of development shall be presented as the basis for gradual development following examination of the scope, pertinent issues, and means of improvement of the marketing information systems. 3. Summary and Conclusion: As the competition among the enterprises has become keen and thus the management of the contemporary enterprises shows the tendencies of uncertainty as well as complexity, all the managers must make the correct and prompt decision of their mind. Otherwise, the danger which will lead to and failure in the failure in the business may befall to the enterprise. Though computer system and information related techniques have the endless potentiality for the improvement of the enterprise, those are granted only to the enterprise which will be able to manage the computer system and information related techniques. In the contemporary industrial society, the need to a managerial information system has been increasing because all the complicated information can be stored, disposed and managed by the efficient method. And the marketing information system is also the integrated system which has been formed and developed through the efficient mixture of all the constituent elements including the definition of marketing research as the definition of the information system has been enlarged due to the reason shown above. The common point of the two systems is the man machine system functioning to help the efficient decision of the mind by introducing the computer system on the basis of user manager centered thought in order to provide informations to be useful in operation and management of the organization and the function of the mind decision. The purpose for the marketing information system lies in making the utmost use of marketing information available in the course of the mind decision. The reason why the contemporary enterprises necessitate the marketing information system are as follows: 1) The stages of the business operation are expanded wide to the world. 2) As the living standards of the consumers have been on the rise, the enter prise has to satisfy the consumer's "wants" than simple "needs".

• 한국건설순환자원학회논문집
• /
• 제5권4호
• /
• pp.496-502
• /
• 2017

본 연구의 목적은 콘크리트 구조물에 존재하는 균열의 깊이 및 보수 성능 평가에 표면탄성파 기반 비파괴 성능 평가 기술의 적용 가능성 및 유효성을 검토하는데 있다. 이를 위해, 콘크리트 배합비의 영향을 최소화하기 위하여 동일한 배합비와 서로 다른 균열 깊이(0, 15, 30, 45mm)를 가지는 사각형 모양의 표면탄성파 투과 시험용 실험체를 준비하였다. 투과계수와 스펙트럼에너지투과비는 표면탄성파 파라미터로써 본 연구에 균열 깊이 변화 및 보수 성능 평가에 활용하였다. 이 때, 균열 보수 성능평가를 위하여 실험체 균열면에 에폭시 주입 전/후로 각 5회씩 반복하여 표면탄성파 실험의 신뢰성을 높여주었다. 균열 깊이 증가에 따라 스펙트럼에너지투과비의 감소를 명확하게 확인하였다. 균열면이 완전하게 보수된 콘크리트 실험체에서 측정한 스펙트럼에너지투과비는 무균열 실험체에서 측정한 값에 대비하여 95% 수준으로 계측되어, 표면탄성파 기반 비파괴 시험 기법이 균열 보수 성능 평가 기술로 활용할 수 있을 것으로 사료된다.

• Journal of Preventive Medicine and Public Health
• /
• 제29권1호
• /
• pp.51-65
• /
• 1996

The purpose of this study was to examine the trends of length of hospital stay (LOS), which is most likely to be a major attribute to hospital performance. From 1984 to 1994, an average LOS of each hospital was analyzed by factors such as medical departments, bed size, occupancy rate, region and ownership. This study was analyzed changing rate of LOS during 11 years. This rate was calculated by simple regression, which was used only with hospital without missing data during 11 years. This study findings are as follows. 1. The results indicated that the average LOS was steadily increased until 1990 but it was slightly decreased after 1990. 2. This trend could be found in all hospital scale and all group of occupancy rate. Specifically this trends of LOS were found in internal medicine, corporate owned hospitals, and hospitals in major city. But LOS of individual owned hospital was continuously increased until 1994. 3. Means of changing rates of LOS were calculated from 1984 to 1994. If we devided it into two parts, before 1990 and after 1990, most changing rates of LOS before 1990 except individual owned hospital were found positive sign. The changing rates after 1990 were negative sign but small hospital(lesser then 200 bed), individual owned hospital, national & public hospital and hospital in small urban have little change of LOS after 1990. Finally from this results we thought that most hospitals in Korea began to be concerned with LOS. Nevertheless LOS of several hospital such as small hospital or individual owned hospital was increased. And this trend may be caused by a few patients, low occupancy rate, or low profit. This trend of LOS is different from that of other countries. Perhaps this phenomenon is resulted from the reimbursement method. Because of fee for service reimbursement system in Korea the hospitals didn't need to shorten LOS in order to save the cost and increase the profit. Therefore reform of hospital cost reimbursement method will be needed to reduce hospital cost in Korea. We thought that the Korean health authority should consider the reimbursement method by unit of bundle of services, for example DRG and prepayment in the United States. This study presents some limitations such as no insight of severity of disease, case-mix measurement of hospital, and other clinical characteristics that can. possibly affect LOS. However, this study reports an important trend in LOS from 1984 to 1994.

• 한국도로학회논문집
• /
• 제17권3호
• /
• pp.49-58
• /
• 2015

PURPOSES : The use of environmentally friendly construction methods has been recently encouraged to reduce fuel consumption and the effects of global warming. For this purpose, the roller compacted concrete pavement (RCCP) construction method has been developed. RCCP is more environmentally friendly and economically efficient than general concrete by reducing the amount of CO2 generated through the application of a smaller amount of cement. RCCP has a number of advantages such as an easy construction method, low cost, high structural hydration performance, and aggregate interlocking. However, mix design standards and construction guidelines of RCCP are required for domestic application. In addition, a study on aggregate selection, which has an effect on the characteristics of RCCP, is necessary owing to a limited number of researches. Thus, the aggregate effect on the performance of RCCP in securing the required strength and workability was evaluated in consideration of domestic construction. METHODS : Sand and coarse aggregates of both 19mm and 13mm in maximum size were used in this study. Four types of aggregate gradations (s/a = 30%, 58%, and 70% for the sand and coarse aggregate of 19mm in maximum size, and s/a = 50% for a combination of the three types of aggregates) were set up to investigate the effects of the PCA band on the RCC characteristics. The conditions of s/a = 30% and 70% were evaluated to check the gradation effect outside of the recommended band. The conditions of s/a = 58% and 50% were used because they are the optimum combination of the two and three types of aggregates, respectively. RCCP gradation band was suggested gradation with a proper construction method of RCCP by synthetically comparing and analyzing the correlation of optimum water content, maximum dry density, and strength of requirements through its consistency and compaction test. RESULTS : The lower and upper limit lines are insufficient to secure a relatively strong development and workability compared to an aggregate gradation in the RCCP gradation band region. On the other hand, the line in the RCCP gradation band and the 0.45 power curve in the RCCP gradation band region were satisfactory, ensuring the required strength and workability. CONCLUSIONS : The suitable aggregate gradation on RCCP process should meet the RCCP gradation band area; however, fine particles passing through a #60 sieve do not need to be within the recommended gradation band because the influence of this region on such fine particles is small.

• 콘크리트학회논문집
• /
• 제26권6호
• /
• pp.751-759
• /
• 2014

현재 전 세계적으로 지구온난화로 인하여 폭염, 폭설, 폭우 및 슈퍼태풍 등과 같은 이상 기후 및 극한 기후현상이 지속적으로 증가 하고 있다. 또한 심각한 자연재해로 콘크리트 구조물 및 사회기반시설의 심각한 손상과 노후화가 발생하였다. 이러한 문제를 해결하기 위해서 현재 국내외적으로 다양한 기후변화에 적합한 시공기술 및 기준에 대한 연구가 활발히 진행되고 있는 실정이다. 그러므로 본 연구에서는 콘크리트 배합에 다양한 풍속과 일조시간의 양생조건에 대한 강도 발현 효과를 평가하고자 한다. 다양한 풍속과 일조시간 조건에서 양생한 실험체에 압축강도와 할렬인장강도 실험을 하였고, 성능 중심 평가(performance based evaluation (PBE))를 수행하여 콘크리트의 다양한 양생조건에 대한 만족도 확률을 평가하였다. 또한 콘크리트의 성능 중심 평가로부터 얻는 결과 값을 바탕으로 콘크리트 배합과 양생조건에 대한 문제점들을 파악 해결하고 대응책을 마련하고자 한다.

• 한국건축시공학회지
• /
• 제21권1호
• /
• pp.11-19
• /
• 2021

본 연구는 타일 떠붙임 시멘트 모르타르의 시멘트 : 잔골재의 혼합 비율인 모르타르 배합비에 따른 품질 특성 및 시공성에 대한 관능 평가를 실시한 것이다. 즉, 타일 시공 후 타일 탈락 하자와 관련한 타일 부착량 및 바탕 부착 하중 시험을 통해 타일 떠붙임 시공 시 콘크리트 바탕면과 타일면의 부착 성상이 서로 다른 것을 알 수 있었다. 또한, 시공성에 관한 관능 평가 결과 타일 떠붙임 모르타르의 시멘트에 대한 잔골재의 질량 비율인 S/C 6 이상은 도기질 타일과의 초기 부착성은 우수하나, 마감 조정성이 불량하고, 바탕면에서 처짐 발생 우려가 있다. 반면, S/C 4 이하는 마감 조정성은 좋으나, 초기 부착성이 저하하고, 바탕면에서 점성에 의한 처짐 등으로 시공성이 저하하며, 부착강도가 저하하여 타일과 모르타르의 계면 탈락 우려가 있는 것으로 평가되었다. 따라서 도기질 타일용 타일 떠붙임 모르타르의 우수한 품질 및 시공성을 확보하기 위해서는 S/C 5 전후가 가장 적정한 혼합 비율로 평가되었다.

• 한국방사선학회논문지
• /
• 제17권1호
• /
• pp.79-90
• /
• 2023

본 논문은 원자력발전소(원전) 사고에 의한 조기사망의 사회적 비용을 추정하기 위해 조건부가치측정법(Contingent Valuation Method, CVM)을 이용하여 통계적 생명가치(Value of a Statistical Life, VSL)를 추정한다. VSL 추정치는 약 35억 5천만 원이다. 이에 세계 원전 역사상 발생한 모든 사고 사망자수 약 181만 명을 곱하여 추정한 사회적 비용은 1,952조 원으로서 한국의 2022년 실질 GDP에 비견되는 수준이다. 연평균 조기사망자수와 사회적 비용은 각각 26,000명과 28조 원이다. 1987~2021년간 세계 화력발전소의 사고와 대기오염물질 배출로 인해 발생한 조기사망의 사회적 비용 추정치는 26,919조 원인데, 이는 미국의 2021년 GDP 규모에 상당하는 규모로서 9조 원을 기록한 원전의 약 3,000배에 달한다. 2021년 한 해만 보더라도, 화력발전소의 사회적 비용은 1,075조 원에 달하지만, 원전은 2,920억 원에 불과하다. 한국의 경우, 2050 탄소중립 정책의 영향으로 재생에너지 발전 비중이 증가할 것이므로, 화력발전 대비 원자력발전 비중을 증가시키는 에너지믹스를 제안한다. 본 논문은 또한 효율적인 에너지 정책을 담보하기 위해 CVM을 이용한 VSL 추정 연구를 지속적으로 축적할 필요가 있음을 강조한다.

• 한국도로학회논문집
• /
• 제18권6호
• /
• pp.97-104
• /
• 2016

OBJECTIVES : The objective of this research is to develop additives for the modification of Solvent DeAsphalting Residue (SDAR) to be used as pavement materials, and evaluate the performance of asphalt mixture manufactured using the SDAR modified by developed additives. METHODS : The SDAR generally consists of more asphaltenes and less oil components compared to the conventional asphalt binder, and hence, the chemical/physical properties of SDAR are different from that of conventional asphalt binder. In this research, the additives are developed using the low molecular oil-based plasticizer to improve the properties of SDAR. First, the chemical property of two SDARs is analyzed using SARA (saturate, aromatic, resin, and asphaltene) method. The physical/rheological properties of SDARs and SDARs containing additives are also evaluated based on PG-grade method and dynamic shear-modulus master curve. Second, various laboratory tests are conducted for the asphalt mixture manufactured using the SDAR modified with additives. The laboratory tests conducted in this study include the mix design, compactibility analysis, indirect tensile test for moisture susceptibility, dynamic modulus test for rheological property, wheel-tracking test for rutting performance, and direct tension fatigue test for cracking performance. RESULTS : The PG-grade of SDARs is higher than PG 76 in high temperature grades and immeasurable in low temperature grades. The dynamic shear modulus of SDARs is much higher than that of conventional asphalt, but the modified SDARs with additives show similar modulus compared to that of conventional asphalt. The moisture susceptibility of asphalt mixture with modified SDARs is good if, the anti-stripping agent is included. The performance (dynamic modulus, rutting resistance, and fatigue resistance) of asphalt mixture with modified SDARs is comparable to that of conventional asphalt mixture when appropriate amount of additives is added. CONCLUSIONS : The saturate component of SDARs is much less than that of conventional asphalt, and hence, it is too hard and brittle to be used as pavement materials. However, the modified SDARs with developed additives show comparable or better rheological/physical properties compared to that of conventional asphalt depending on the type of SDAR and the amount of additives used.