• Earthquakes and Structures
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• 제14권5호
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• pp.411-424
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• 2018

This study explores the inelastic behavior of systems with flexible base. The use of a single degree of freedom system (ESDOF) with equivalent ductility to represent the response of flexible base systems is discussed. Two different equations to compute equivalent ductility are proposed, one which includes the contribution of rigid body components, and other based on the overstrength of the structure. In order to asses the accuracy of ESDOF approach with the proposed equations, the behavior of a 10-story regular building with reinforced concrete (RC) moment resisting frames is studied. Local and global ductility capacity and demands are used to study the modifications introduced by base flexibility. Three soil types are considered with shear wave velocities of 70, 100 and 250 m/s. Soil-foundation stiffness is included with a set of springs on the base (impedance functions). Capacity curves of the building are computed with pushover analysis. In addition, non linear time history analysis are used to asses the ductility demands. Results show that ductility capacity of the soil-structure system including rigid body components is reduced. Base flexibility does not modify neither yield and maximum base shear. Equivalent ductility estimated with the proposed equations is fits better the results of the numerical model than the one considering elastoplastic behavior. Modification of beams ductility demand due to base flexibility are not constant within the structure. Some elements experience reduced ductility demands while other elements experience increments when flexible base is considered. Soil structure interaction produces changes in the relation between yield strength reduction factor and structure ductility demand. These changes are dependent on the spectral shape and the period of the system with fixed and flexible base.

• 한국융합학회논문지
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• 제10권12호
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• pp.169-175
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• 2019

본 연구는 경도의 지적장애를 가진 20대 대학생이 다양하게 누운 자세변화 따른 복합적 폐활량에 미치는 영향을 알아보고자 하였다. 경도의 지적장애를 가진 20대 남자 대학생 20명을 대상으로 실험에 참여하였다. 실험 대상자들은 누운 자세, 오른쪽 옆으로 누운 자세, 원쪽 옆으로 누운 자세, 엎드러 누운 자세에 따라 폐기능 측정기를 이용하여 폐활량을 평가해 보았다. 자료분석은 SPSS 18.0 버전을 이용하여 실험 대상자의 자세변화에 따란 호흡변화를 분석하기 위해 일요인 반복측정 분산분석으로 검증하였다. 결과는 오른쪽 옆으로 누운 자세에서 폐활량이 가장 크게 나타났고 엎드러 누운 자세에서 가장 낮게 나타났다. 이 연구를 통해 경도의 지적장애인이 일상이나 임상에서 침상생활을 할 때 취침에서 가장 안정된 호흡능력을 확보할 수 있는 이상적인 누운 자세를 제시하고 효율적 환기능력에도 긍정적인 효과를 나타날 것으로 생각된다.

• Steel and Composite Structures
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• 제28권3호
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• pp.309-318
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• 2018

Buckling Restrained Braced (BRB) frames have been widely used as an efficient seismic load resisting system in recent years mostly due to their symmetric and stable hysteretic behavior and significant energy dissipation capacity. In this study, to provide a better understanding of the behavior of BRB frames with various beam-column connections, a numerical study using non-linear finite element (FE) analysis is conducted. All models are implemented in the Abaqus software package following an explicit formulation. Initially, the results of the FE model are verified with experimental data. Then, diverse beam-column connections are modeled for the sake of comparison from the shear capacity, energy dissipation and frame hysteresis behavior points of view until appropriate performance is assessed. The considered connections are divided into three different categories: (1) simple beam-column connections including connection by web angle and connection by seat angle; (2) semi-rigid connection including connection by web and seat angles; and (3) rigid beam-column connections by upper-lower beam plates and beam connections with web and flange splices. Results of the non-linear FE analyses show that these types of beam-column connections have little effect on the maximum story drift and shear capacity of BRB frames. However, the connection type has a significant effect on the amount of energy dissipation and hysteresis behavior of BRB frames. Also, changes in length and thickness of the angles in simple and semi-rigid connections and changes in length and thickness of plates in rigid connections have slight effects (less than 4%) on the overall frame behavior.

• 대한교통학회지
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• 제31권1호
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• pp.77-86
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• 2013

본 고는 신호교차로 영향권에서 수행되는 도로점용공사가 유발하는 신호교차로의 정지선에서의 유출 가능량, 다시 말해 포화교통류율의 변화를 산정하여 해당 접근 차로군의 용량을 계산할 수 있는 해석적 모형의 개발에 초점을 맞추고 있다. 해석적 모형이 가진 설명력의 간결함과 산정 정확도를 제고하기 위하여 선행연구의 모형논리를 크게 바꾸고 상당한 수정을 가하였다. 또 모형의 검증을 위해서 많은 노력이 보태졌는데, 다양한 미시 모의실험 결과와의 비교 뿐만 아니라 실제 공사현장에서 수집된 많은 자료를 바탕으로 하는 현장 대표 값들과의 비교 등이 수행되었다. 포화교통류율은 도로점용공사의 위치, 정지선과 공사구간과 이격거리, 개방 및 폐쇄 차로 수, 유효녹색시간 등에 상당히 민감하게 변화한다는 것이 확인되었으며, 공사현장의 특성을 구성하는 그와 같은 기하구조 및 신호운영관련 조건 등을 변수로 하는 제안 모형들은 아주 적은 오차 범위 내에서 성공적으로 포화교통류율을 산정해 낼 수 있음을 보여 주었다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권8호
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• pp.1186-1194
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• 2019

Objective: The influence of broiler carcass scalding conditions on chicken breast meat quality parameters was investigated. Methods: Two hundred and seventy Cobb broiler chickens from 42 to 48 days old were slaughtered according to the standard industry practice and scalded in five temperature/time combinations-$T_1$, $54^{\circ}C/210s$; $T_2$, $55^{\circ}C/180s$; $T_3$, $56^{\circ}C/150s$; $T_4$, $57^{\circ}C/120s$; $T_5$, $58^{\circ}C/90s$. Results: Scalding temperature increase resulted in higher values of external and ventral lightness and in protein functionality reduction-determined by emulsification capacity and protein denaturation-in chicken breast fillets 24 h post-mortem. Protein secondary structures had conformational changes, with a decrease of the ${\alpha}$-helix and an increase of the ${\beta}$-sheet and ${\beta}$-turn proportions, mainly in $T_1$ and $T_5$ samples, determined by Fourier-transform infrared spectroscopy in an attenuated reflectance mode analysis. The chemical composition, pH, water holding capacity and Warner-Bratzler shear force did not differ among the treatments. In the fatty acid profile, the 18:1n-9 was lower in $T_5$, which suggested that the high scalding-temperature could have caused the lipid oxidation. The values of the polyunsaturated fatty acids (PUFA), such as 22:2, 20:4n-6, and 22:6n-3, were highest in the $T_5$, thus being related to the phospholipid cellular membrane collapse in this experimental condition and subsequent release of these PUFA. Conclusion: Intermediate scalding-parameters avoided the negative changes in the chicken meat quality.

• 복식문화연구
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• 제11권4호
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• pp.551-561
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• 2003

The regulations for costume were set to improve people's moral fiber and cultural standards. In the 17th and 18th century, the main aim of this regulation was to prohibit luxury. But being the turning point to a modem state, with breaking social status and development of commerce, industry, and the mind of imitation, regulation for luxury wasn't enforced, but rather it brought many revolutionary changes in costume. Restraining human impulse to express beauty was no longer subject to regulation. Therefore, people started to recognize the human figure with shorter Jegory(저고리) and strengthened ceremonial capacity by broadening po's(포) sleeves. The silk fabrics were the most popular fabric during this era, special patterns were added for decoration and also for blessings. Complementary colors were used for contrast on the collar (깃), cuffs (끝동), Gyotrnagi (곁마기), and sash (고름). This color composition gave a younger and more active look. And with red stripes on the sleeves, it emphasized the beauty of the color arrangements as well as providing protection from the devil.

• 한국통신학회논문지
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• 제32권4B호
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• pp.208-216
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• 2007

Wireless Sensor Networks (WSNs) are characterized by low capacity on each nodes and links. Wireless links have high bit error rate (BER) parameter that changes frequently due to the changes on network topology, interference, etc. To guarantee reliability in an error-prone environment, a retransmission mechanism can be used. In this mechanism, the number of retransmissions is used as a parameter that controls reliability requirement level. In this paper, we propose an Error Adaptive Transport Protocol (EATP) for WSNs that updates the number of retransmissions regularly to guarantee reliability during bit error rate changes as well as to utilize energy effectively. The said algorithm uses local information, thus, it does not create overhead problem.

• 한국시스템다이내믹스연구
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• 제6권2호
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• pp.73-93
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• 2005

This paper on an experiment, using System Dynamics, on the affect of increase in number of beds and medical instruments used for the care of premature infants, which constitute the physical requirements in quality of medical services, on changes in the survival rate of premature in ants that leads to demographic changes of Newborn infants. The model has four sectors: take-in capacity, survival rate of premature infants, demographics without newborn infants and demographics with newborn infants. The model simulates the changes in demographics of the newborn infants from 2002 to 2022. The study results show that the survival rate of premature infants can be increased by improving the physical aspects in the quality of medical services. An average of 1,900 premature infants can survive as a result of the physical quality improvements in medical services, adding up to an increase of 37,300 newborn infants by the year 2022.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.184-185
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• 2021

Based on changes in capacity demanded by society as a result of the 4th industrial revolution, as well as changes in the environment due to COVID19, it is necessary to adopt new educational methods in Korean universities. In response to such changes, there have been attempts to apply innovative teaching methods, such as flipped learning and blended learning. However, most studies are limited to either learning effects and/or satisfaction. Accordingly, this study seeks to contribute to the changing educational methods by developing online and offline blended building construction curriculum. The results of this study are as follows: combined education was made possible by developing a curriculum by dividing the online and offline environments. It is determined that the developed curriculum will be efficient and appropriate for the new environments.

• 대한건축학회논문집:계획계
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• 제34권10호
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• pp.3-12
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• 2018

This research aims at analyzing the changes in residential environment after a residential environment improvement project focusing on the analysis into the physical environment of a residential environment improvement project, and examining in what direction the changes by residents' own efforts occurred after public support, such as infrastructure. The present residence development method has become different from the previous pulling down method and is focused on regeneration. By examining in what direction the target residence is being changed because of the development by residents' own efforts after the government's public investment at this time, this study also aims at investigating the direction to develop a guideline for residential improvement for later improvement of deteriorated residence. As for the contents of the analysis, changes in public support, such as infrastructure, and other areas after the residential environment improvement project were compared and analyzed from the land use, street system, and condition of buildings before the residential environment improvement project through field survey, geographic information system(GIS), registered land and building data and so on. The biggest change since the support from the government was that at the beginning of the project, the application of special provision of building laws and different financial supports led to lots of newly built buildings. Since then, their number has decreased rapidly, and in most cases, there have been some changes in part, such as changes in the use of land or repair of disposal tanks. Most newly built buildings were multi-household houses, and it has caused road capacity and parking lot capacity, etc., to be exceeded, which has worsened the pleasantness of the living environment. In addition, other problems have also appeared, for example, the lack of residence supporting facilities yet with a higher level of residential density. Regarding the changes in the residential environment after the residential environment improvement project, maintenance of houses were conducted in some degree as diverse alleviation policies to improve poor residence, yet the absence of the guideline for the direction of developing the whole district has made the residence environment more dense and deteriorated. To solve these problems, in advance to a residential improvement project, specific management methods based on short-, mid- and long-term plans for the direction of development by residents' own efforts and a sustainable guideline seem to be necessary.