• Journal of Biosystems Engineering
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• 제26권4호
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• pp.371-378
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• 2001

This research devoted to develop an incubator that could make an optimum environment condition according to days of age for suckling pigs to decrease the mortality and improve the rate of the weight gain of the suckling pigs. Results obtained from this research summarized as follows: 1. Several experiments were carried out at the farm to find the effect of incubator developed for suckling pigs on weight gain by season. The total average gain of the weight of the treatment group was around 6∼22kg, and 6∼23kg higher than control group at the first experiment (April 19), at the second (July 30), and at the third (September 23), year of 2000 experiment, respectively. There were no significant differences ($\alpha$=5%) of the total weight gain among treatment groups. There was, however, a significant difference ($\alpha$=5%) of the total weight gain between the control and treatment groups and it was considered to be that the incubator had efficiency for weight gain of the suckling pigs. 2. The survival rate of the control group was 87% in the total sample number of 92, meanwhile, which of the experiment group was 98% in the total sample number of 50 suckling pigs. 3. Finally, economic analysis was executed for suckling pigs based on a farm size of breeding 500 sows. The results showed that a break-even point was around 9 months and the annual profit of ￦52,265,694 was expected after the break-even point.

• 한국공간구조학회논문집
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• 제10권1호
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• pp.51-58
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• 2010

ETFE 필름 막재는 Ethylen Tetra Fluoro Etylene의 약자로, 무색의 투명한 막재료이다. ETFE 필름 막재는 내화학성이 있고 매우 가벼운 장점이 있는 것으로 알려져 있다. ETFE 필름 막재는 $50{\mu}m$에서 $300{\mu}m$의 두께가 주로 사용되며, 인장강도는 40MPa에서 60MPa 300%에서 400%정도이다. 본 연구에서는 최근 해외에서 초대형 박구조물의 박재료로 시용되는 ETFE 필름 막재에 대한 기초적 역학적 특성을 조사하기 위하여 인장시험을 수행하였다. 인장시험으로부터 인장강도, 인장연신율, 영계수(Young's Modulus) 등 건축 설계 시 필요한 기초적 자료를 제공하고자 한다.

• Bulletin of the Korean Chemical Society
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• 제32권10호
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• pp.3743-3747
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• 2011

Kinetic studies on the reactions of Y-S-aryl phenyl phosphonochloridothioates with X-pyridines have been carried out in MeCN at $55.0^{\circ}C$. The Hammett and Bronsted plots for substituent X variations in the nucleophiles are biphasic concave upwards with a break point at X = H. The Hammett plots for substituent Y variations in the substrates are biphasic concave upwards with a break point at Y = H, and the sign of ${\rho}_Y$ is changed from unusual negative (${\rho}_Y$ < 0) with the weaker electrophiles to positive (${\rho}_Y$ > 0) with the stronger electrophiles. The stepwise mechanism is proposed on the basis of the ${\rho}_X$, ${\beta}_X$, and ${\rho}_{XY}$ values as follows: a ratelimiting leaving group departure from the intermediate involving a frontside attack and product-like TS for the stronger nucleophiles and weaker electrophiles; a rate-limiting leaving group departure from the intermediate involving a backside attack and product-like TS for the weaker nucleophiles and electrophiles; a rate-limiting bond formation involving a frontside attack for the stronger nucleophiles and electrophiles; a rate-limiting bond formation involving a backside attack for the weaker nucleophiles and stronger electrophiles. The substituent effects of X and Y on the pyridinolysis mechanisms of $R_1R_2P$(=S)Cl-type substrates are discussed.

• Industrial Engineering and Management Systems
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• 제15권3호
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• pp.259-267
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• 2016

In Wireless Sensor Network, various routing protocols were employed by our Research and Development community to improve the energy efficiency of a network as well as to control the traffic by considering the terms, i.e. Packet delivery rate, the average end-to-end delay, network routing load, average throughput, and total energy consumption. While maintaining network connectivity for a long-term duration, it's necessary that routing protocol must perform in an efficient way. As we discussed Optimized Link State Routing protocol between all of them, we find out that this protocol performs well in the large and dense networks, but with the decrease in network size then scalability of the network decreases. Whenever a link breakage is encountered, OLSR is not able to periodically update its routing table which may create a redundancy problem. To resolve this issue in the OLSR problem of redundancy and predict link breakage, an enhanced protocol, i.e. S-OLSR (More Scalable OLSR) protocol has been proposed. At the end, a comparison among different existing protocols, i.e. DSR, AODV, OLSR with the proposed protocol, i.e. S-OLSR is drawn by using the NS-2 simulator.

• Nuclear Engineering and Technology
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• 제45권3호
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• pp.347-360
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• 2013

This paper presents an experimental investigation of the small-break loss-of-coolant accident (SBLOCA) and the loss-of-feedwater accident (LOFW) in a scaled integral test facility of REX-10. REX-10 is a small integral-type PWR in which the coolant flow is driven by natural circulation, and the RCS is pressurized by the steam-gas pressurizer. The postulated accidents of REX-10 include the system depressurization initiated by the break of a nitrogen injection line connected to the steam-gas pressurizer and the complete loss of normal feedwater flow by the malfunction of control systems. The integral effect tests on SBLOCA and LOFW are conducted at the REX-10 Test Facility (RTF), a full-height full-pressure facility with reduced power by 1/50. The SBLOCA experiment is initiated by opening a flow passage out of the pressurizer vessel, and the LOFW experiment begins with the termination of the feedwater supply into the helical-coil steam generator. The experimental results reveal that the RTF can assure sufficient cooldown capability with the simulated PRHRS flow during these DBAs. In particular, the RTF exhibits faster pressurization during the LOFW test when employing the steam-gas pressurizer than the steam pressurizer. This experimental study can provide unique data to validate the thermal-hydraulic analysis code for REX-10.

• International Journal of Internet, Broadcasting and Communication
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• 제15권2호
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• pp.118-123
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• 2023

With the continuous development of emerging technologies represented by VR technology, many game developers are declaring that they are constantly trying to break the "fourth wall" and break the boundaries between virtual and reality to create game immersion for players. new game. But for many gamers, a strong sense of immersion is not the focus of their pursuit. The sense of control and safe exploration during the game is also the game experience that many gamers are pursuing. Moreover, there is ambiguity in the definition of the concept of breaking the fourth wall in the field of academic theory. The purpose of breaking the fourth wall was to separate the real world from the virtual world, to remind the audience that the actors and the audience are in two different worlds, and to trigger the audience's thinking about drama and deeper philosophy. But in the current game, it has become a blurring of the boundary between virtual and reality, pulling players into the virtual world, and focusing on the immersive experience. In this paper, we will first sort out the concept of "breaking the fourth wall", and then conduct a comparative analysis of horizontal scroll games and VR games, and conclude that the "fourth wall" has an impact on players Great conclusion.

• Nuclear Engineering and Technology
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• 제55권1호
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• pp.144-155
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• 2023

The core catcher is used as a passive safety system in new generation nuclear power plants to create a space in the containment for the placing and cooling of the molten corium under various severe accidents. This research investigates the role of the core catcher in the VVER-1000 reactor containment system in mitigating the effects of core meltdown under various severe accidents within the context of the Ex-vessel Melt Retention (EVMR) strategy. Hence, a comparison study of three severe accidents is conducted, including Station Black-Out (SBO), SBO combined with the Large Break Loss of Coolant Accident (LB-LOCA), and SBO combined with the Small Break Loss of Coolant Accident (SB-LOCA). Numerical comparative simulations are performed for the aforementioned scenario with and without the EX-vessel core-catcher. The results showed that considering the EX-Vessel core catcher reduces the amount of hydrogen by about 18.2 percent in the case of SBO + LB-LOCA, and hydrogen production decreases by 12.4 percent in the case of SBO + SB-LOCA. Furthermore, in the presence of an EX-Vessel core-catcher, the production of gases such as CO and CO2 for the SBO accident is negligible. It was revealed that the greatest decrease in pressure and temperature of the containment is related to the SBO accident.

• 한국터널지하공간학회 논문집
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• 제15권3호
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• pp.311-320
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• 2013

이 논문은 쉴드TBM 추진시 잭킹 force에 의한 세그먼트 두께의 영향에 대한 현장사례연구이다. 이 연구를 위하여 조사현장의 지반 특성에 대하여 분석하고 현장 조사 자료를 통한 쉴드TBM공사시 문제점에 대하여 분석하였다. 실질적으로 잭킹에 의한 터널 추진시 세그먼트가 부분적으로 파손된 것으로 추측되었다. 이에 따라 세그먼트의 파손에 대하여 조사하였으며, 파손 원인에 대하여 다각적으로 수치 해석적 및 이론적으로 평가를 실시하였다. 결과로부터 파손의 주원인들은 잭킹 시스템과 세그먼트의 두께가 얇은데 있다는 것으로 추측되었다. 추가로 연구 결과를 근거로 향후 얇은 세그먼트의 안전한 설치를 위한 추진 잭킹 방법에 대하여서도 제안하였다.

• 마케팅과학연구
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• 제15권1호
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• pp.81-103
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• 2005

이 연구는 빈번한 가격할인을 하고 있는 국내 의류시장에서 소비자들이 가격이 떨어질 것을 기대하여 제품의 구입을 늦추는 '가격기대효과'가 실제로 존재하는지 실증적으로 분석하고자 하는 데 그 목적이 있다. 특히, 지금까지의 가격연구에서는 규범적 행태적 서술적 연구 등 각 분야의 영역을 접목시킨 통합적 접근이 미진하여 소비자의 심리적 요인을 가격책정에 반영한 시도가 드물었고 시간의 흐름에 따라 변화 하는 가격과 판매량의 관계를 살피는 동태적 연구가 부족하기 때문에, 규범적 연구와 행태적 연구를 접목시켜 의류제품의 가격기대효과를 밝혀내고자 하였다. 이를 위해 기존의 의류제품에 적합한 동태적인 가격기대효과 모델을 수립하였으며 모델을 검증하기 위하여 국내 백화점의 여성복 판매 데이터를 이용하였다. 분석결과 국내 의류제품을 구매하는 소비자들에게 가격기대효과가 존재한다는 사실을 이론적, 실증적으로 밝혀내었다. 이러한 결과는 패션제품의 가격변화에 따른 소비자들의 독특한 구매행동을 반영한 것으로 기존의 동태적 가격연구의 범위를 넓혔다는데 의의가 있다.

• 보존과학회지
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• 제30권1호
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• pp.81-93
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• 2014

철원 도피안사 철조비로자나불좌상, 동해 삼화사 철조노사나불좌상, 평택 만기사 철조여래좌상은 통일신라에서 고려시대에 조성된 철불로서 균열, 탈락, 박리박락, 각종 오염물 등이 발생하였다. 방사선 투과촬영을 활용한 철불의 손상도 평가 결과, 철불 내부에서는 균열, 이격, 탈락, 주물공, 보수물질 등이 확인되었다. 그러나 철의 강도로 보아 외부로부터 큰 충격이 가해지지 않는 이상 현재의 상태를 유지할 수 있을 것으로 보인다. 철불의 제작에는 내형과 외형을 철심과 못을 사용하여 고정하였으며, 표면의 이음선과 양각된 명문, 따로 주조되어 결합된 손으로 보아 초중자주조법으로 조성되었을 것으로 판단된다.