PURPOSES : This paper numerically evaluates the contribution of transverse steel to the structural behavior of continuously reinforced concrete pavements to understand the role of transverse steel. METHODS: Two-lane continuously reinforced concrete pavements with and without transverse steel were analyzed through finite element analysis with the aid of commercial finite element analysis program DIANA; the difference in their structural behavior such as deflection, joint opening, and stress distribution was then evaluated. Twenty-node brick elements and three-node beam elements were used to model concrete and steel, respectively. Sub-layers were modeled with horizontal and vertical tensionless spring elements. The interactions between steel and surrounding concrete were considered by connecting their nodes with three orthogonal spring elements. Both wheel loading and environmental loading in addition to self-weight were considered. RESULTS : The use of transverse steel in continuously reinforced concrete pavements does not have significant effects on the structural behavior. The surface deflections change very little with the use of transverse steel. The joint opening decreases when transverse steel is used but the reduction is quite small. The transverse concrete stress, rather, increases when transverse steel is used due to the restraint exerted by the steel but the increase is quite small as well. CONCLUSIONS : The main role of transverse steel in continuously reinforced concrete pavements is supporting longitudinal steel and/or controlling unexpected longitudinal cracks rather than enhancing the structural capacity.
Recently the creative education is being discoursed actively for the primary and the secondary school in Korea. It makes students get the creativity and the alternative knowledge which is merged in the new solution for solving some problems that they can meet in their life. On the other hand, Game Based Learning (G-Learning) has been approved it's educational effects not only in Korea but also all over the world. This study tried to consider G-Learning as educational methods for improving the creativity. To put it concretely, the purpose of this study is inquiry useful strategies for designing the G-Learning considering factors for the creativity. There are many scholars who has been researching about the creativity factors such as Guilford, Torrance, Anderson or Clark and so on. This study inquired some strategies into the G-Learning considering creativity factors by Guilford and Torrance who had researched creativity factors for the primary and the secondary school students. For the game design theory, this study examined Whitton's one because he had reported one of the most comprehensive game design strategies. Finally, this study inquired game design strategies based on merging the creativity factors by Guilford with the game design strategies by Whitton. It suggests useful strategies for the game designer who are willing to develop some games for improving students' creativity directly or creativity strategies as necessary factors for the G-Learning.
As ICT advances, industries related to digital technology are disrupting the boundaries of corporations and increasingly interested in the industrial ecosystem. The electronic game industry is also continuously growing through convergence among various technologies, content genres and platforms. Accordingly, this study analyzed the hierarchical elements of hybrid game contents from the viewpoint of the ecosystem as well as the importance and influence their components have upon each level. To understand the importance and influence of the components of the ecosystem from the viewpoint of the value chain of hybrid game contents, an Expert Delphi Survey was conducted employing 18 experts from the game industry, academia and R&D institutions. The results of the Expert Delphi Survey were compiled, a hybrid game ecosystem defined for each layer, and a communication system diagram created depicting the relationship between the ecosystem and value chain of the hybrid game contents. Based on the analysis, to invigorate hybrid game contents, a direction for policies was presented for each hierarchy from both the micro and macro perspectives.
바이오디젤의 저온유동성과 산화안정성은 주로 녹는점이 높은 포화 및 불포화 지방산 메틸에스테르의 함량에 의해 좌우된다. 본 연구는 동물성 유지인 우지 유래 바이오디젤에 요소를 첨가하여 포화지방산 메틸에스테르 함량을 저감시켜 동물성 바이오디젤의 저온유동성 개선과 포화지방산 메틸에스테르 함량이 저감된 동물성 바이오디젤을 식물성 바이오디젤에 혼합함으로써 식물성 바이오디젤(유채유, 폐식용유, 대두유 및 동백유)의 저온유동성을 개선하기 위해 수행 되었다. 연구결과, 동물성 바이오디젤의 포화도 저감을 통해 저온필터막힘점을 최대 –15℃까지 낮추었고, 포화도가 저감된 동물성 바이오디젤을 식물성 바이오디젤과 혼합함으로서 식물성 바이오디젤의 저온필터막힘점을 -10 ~ -18℃까지 낮출 수 있었다. 본 연구를 통해 동·식물성 유지 유래 바이오디젤의 저온특성을 개선함으로써 국내 겨울철 환경조건에서 연료유로 적용 가능성을 증대할 것으로 기대한다.
In order to overcome the key shortcoming of Hamilton's principle, recently, the extended framework of Hamilton's principle was developed. To investigate its potential in further applications especially for material non-linearity problems, the focus is initially on a classical single-degree-of-freedom elasto-viscoplastic model. More specifically, the extended framework is applied to the single-degree-of-freedom elasto-viscoplastic model, and a corresponding weak form is numerically implemented through a temporal finite element approach. The method provides a non-iterative algorithm along with unconditional stability with respect to the time step, while yielding whole information to investigate the further dynamics of the considered system.
연구의 목적은 마케팅요소에 관한 선행연구를 바탕으로 지역축제의 마케팅요소를 도출하고자 하는 데 있다. 전통적 마케팅 요소 4P와 서비스마케팅 요소 7P, 관광마케팅 요소 8P에 대한 이론적 근거와 지역축제의 마케팅 요소에 대한 다양한 선행연구를 바탕으로, 지역축제 마케팅요소들을 도출하였다. 연구결과로서, 지역축제 마케팅요소로서 Product, Price, Place, Promotion, People, Physical Evidence, Programming 등 7P를 제시하였다.
The purpose of this study is to detect metabolic syndrome components related to exposure of organic solventthrough comparison and analysis of metabolic syndrome components between workers at the workplace exposedto organic solvent (toluene, xylene, styrene) and workers at general workplace. During the period from Januaryto December 2010, the survey was conducted against male workers of 168,769 persons with age group 30-59completed medical checkup, dividing workers at organic solvent exposed work place and workers of generalworkplace against which comparisons were carried out about the result of general characteristics, blood test.Whether exposed to organic solvent and exposed period relationship with metabolic syndrome components wereidentified through execution of multiple logistic regression analysis. The prevalence rate of the metabolic syndromeby age was 15.0% for the 30s, 19.8% for the 40s, 22.9% for the 50s. For the whole workers, the prevalence rateof the metabolic syndrome was 17.4% in exposed workplace and 18.4% in general workplace that was higherthan the rate in exposed workplace. Even if age, drinking, smoking, exercise, region and BMI were corrected,the exposure to the organic solvent was the higher the significance of blood pressure and fasting glucose werestatistically and also the longer the period of exposure was, the higher the significance of blood pressure wasstatistically. In this study, the exposure to the organic solvent showed a statistically significant relevance with bloodpressure and fasting glucose among the metabolic syndrome components and the period of exposure showed astatistically significant relevance with blood pressure. Further researches should be conducted by prospective cohortstudy about the organic solvent and the metabolic syndrome components supplementing the defects.
레벨셋 기법과 무요소법을 결합한 위상 및 형상 최적설계 기법을 개발하여 선형 탄성문제에 적용하였다. 설계민감도는 애드조인트법을 사용하여 효율적으로 구하였다. 해밀턴-자코비 방정식을 업-윈드 기법을 이용하여 수치적으로 풀었으며, 구조물의 경계는 레벨셋 함수를 이용하여 암시적으로 표현하였다. 구조물의 응답과 설계민감도를 얻기 위하여 암시적 함수를 사용하여 명시적 경계를 생성하였다. 재생 커널 기법에 기초하여 얻어진 전역 절점 기저함수를 사용하여 연속체 지배방정식의 변위장을 이산화하였다. 따라서 질점들을 연속체 영역의 어느 곳이든 위치시킬 수 있으며, 이는 통해 명시적 경계를 생성하는 것이 가능하며, 결과적으로 정확한 설계를 얻을 수 있다. 개발된 방법은 제한 조건이 있는 최적설계 문제에 대하여 라그랑지안 범함수를 정의한다. 이는 경계의 변화를 통하여 허용 부피 제한조건을 만족시키면서 컴플라이언스를 최소화한다. 최적설계 과정 동안 라그랑지안 범함수의 최적화조건을 만족시킴으로써 해밀턴-자코비 방정식을 풀기 위한 속도장을 얻는다. 기존의 형상 최적설계 기법에 비하여, 본 방법론은 위상과 형상의 변화를 쉽게 얻어낼 수 있다.
가금에서의 스트레스 지표는 혈중 corticosterone의 농도, heterohphil/lymphocyte 비율 뿐만 아니라 사료 및 물의 섭취량, 체중, 산란율, 이상행동 등도 포함된다. 사육온도, 바닥형태, 사육밀도, 수송, 부리자르기, 제한급이, 질병 등이 사육현장에서 가금이 경험할 수 있는 스트레스 요인이 될 수 있다. 다양한 스트레스 지표 중에서 특정 지표만으로 스트레스의 여부를 평가하는 것은 오류를 범할 수 있으므로 동시에 여러 지표를 이용하여 평가하는 것이 스트레스에 대한 평가의 신뢰도를 향상시킬 수 있다.
People have been experiencing lot of incidents for their lives which results in gaining their impetus. Each impetus derives an emotion and such emotion is either of positive or negative one. The positive emotion motivates activation of his life but the negative emotion demotivates one. Specifically, the negative motivation will be much worse for children and it could be adversely affected to their emotional development. The paper first characterizes how to regulate an emotion in a view of psychology base and also characterizes how to regulate the emotion for children. And then, we analyze serious game contents which have been developed to care a negative emotion for children and youth to derive some game elements to be used in the games. Finally, by combining the two characterizations of regulation of emotion in psychology view and the serious games, we propose effective game elements for caring children’s negative emotion. We expect that the results will provide a good guideline when we make a serious game to care children’s negative emotion.
This writing aims to observe Korean art through keywords such as culture, art and the everydayness and its relationship with mass culture, Korean art after the 1990s and its daily world. It was during the latter part of the 1980s that the Korean society entered mass society. The Asian Games of 1986 and the Seoul Olympic Games of 1988 accelerated the internationalization of Korean society and the local political scene was approaching the political democratization through the 6ㆍ29 Declaration of 1987. Outside Korea, the Soviet Union, which represented the communism block of the world, collapsed, leading to the dismantling of the ideological confrontation between communism and capitalism. The Western postmodernism also made its way to Korea affecting the social ambience and allowing various values to coexist beyond the ideological opposition of the left and the right. The reason why I intend to take the correlation between mass culture and Korean art as the main point of Korean art after the 1990s, is that the quotidian aspect began to be reflected in art due to the emergence of mass culture and the subsequent expansion of art into daily life. This thesis examines how the mass culture and daily element is rendered in Korean art after the 1990s through three categorical points of discussion: Text/comprehension that acts as a sign, Reciprocity/relationship that involves the active intervention of the audience, and Commonness (popular vein)/anti-elitism that reflects the mass sentiment. I paid attention to what happens on the surface of society and its certain regular signs, desires and the fixed ideas in the consumption of text/comprehension, the transgressing between art and life through the process of representation by sharing it with the other, and finally, how art tries to reveal mass sentiment or show a critical consciousness of art that is considered vacant because of its utilization of discarded materials once produced by modern society in commonness (popular vein)/anti-elitism. Such tendency disintegrates the classical norm of art that divides art and life and reflects the alienated quotidian life, ultimately making us re-think our conventional ideas and modes of action. This writing is an attempt to discern the point of change in the development of the Korean contemporary art.
Numerical analysis of a Ni-PZT stacked piezoelectric micro actuator is investigated for the prediction of mechanical behavior as a preceding research for the manufacturing of three dimensional micro structures. Finite element method is adopted to examine the simulation of a piezoelectric actuator according to applied direction of voltage, by researching displacement characterization of piezoelectric material through piezoelectric theory. PZT-4 is selected as a piezoelectric material. And bimorph finite element modeling is employed to study the response of Ni-PZT bi-layered micro actuator under the various input voltages. The results are presented as maximum displacement values under each applied voltages. Maximum displacement of 0.71μm at 60V is obtained
대부분의 급경사지의 붕괴는 지형적으로 불안정한 지역에서 발생한다. 백두산은 전형적인 산악 지역으로 잠재적 폭발 가능성을 지닌 활화산으로 알려져 있다. 본 연구에서는 백두산지역의 수치고도모형을 이용하여 지형요소와 선구조선 분석을 통해 재해 위험도를 작성하였다. 취약도 분석에 사용되는 요소는 지형으로부터 산정된 방위도, 경사도, 상부사면기여면적, 접선구배곡률, 윤곽구배 곡률, 습윤지수의 분포를 이용하였다. 더불어 선구조의 선밀도도를 작성하여 재해 위험도를 평가하는데 이용하였다. 지형요소를 이용한 백두산지역의 재해위험도 분석 결과 남쪽 내지 남서부 지역의 재해 위험도가 4-5등급으로 높게 나타나고 있다.
본 연구는 모바일 폰의 GUI 디자인의 구성요소를 색상, 텍스트, 레이아웃, 그래픽아이콘, 동영상으로 정하고, 이들 요소와 브랜드 선호도와의 관련성을 실버세대를 대상으로 고찰하는 데 목적이 있었다. 이러한 목적을 달성하기 위해 모형을 구축하고 가설을 설정한 후 다중회귀분석으로 검증하였다. 그 결과는 다음과 같다. 첫째, 모바일 폰의 GUI 디자인 구성요소별로 통계적 유의성을 고찰한 결과 색상, 텍스트, 레이아웃, 그래픽 아이콘, 동영상 요소는 제시된 유의수준에서 통계적으로 유의하게 나타남에 따라 이들 요소는 모두 브랜드 선호도에 영향을 미치고 있다고 판단된다. 둘째, 모바일 폰의 GUI 디자인 구성요소들이 브랜드 선호도에 미치는 상대적 영향력의 크기는 텍스트, 색상, 동영상, 그래픽아이콘, 레이아웃 순서로 나타났다. 따라서 실버세대의 경우 모바일 폰의 브랜드 선호도를 높이기 위해서는 ‘텍스트’ 요소와 ‘색상’ 요소를 다른 요소보다 우선적으로 고려해야 함을 알 수 있다. 아울러 ‘텍스트’ 요소와 ‘색상’ 요소의 영향력이 높을수록 브랜드의 선호도는 높아질 것으로 판단된다.
The seismic damage of non-structural components, such as communication facilities, causes direct economic losses as well as indirect losses which result from social chaos occurring with downtime of communication and financial management network systems. The current Korean seismic code, KBC2009, prescribes the design criteria and requirements of non-structural components based on their elastic response. However, it is difficult for KBC to reflect the dynamic characteristics of structures where non-structural components exist. In this study, both linear and nonlinear time history analyses of structures with various analysis parameters were carried out and floor acceleration spectra obtained from analyses were compared with both ground acceleration spectra used for input records of the analyses and the design floor acceleration spectrum proposed by National Radio Research Agency. Also, this study investigates to find out the influence of structural dynamic characteristics on the floor acceleration spectra. The analysis results show that the acceleration amplification is observed due to the resonance phenomenon and such amplification increases with the increase of building heights and with the decrease of structure’s energy dissipation capacities.
위해요소관리 중심의 복숭아 GAP 모델 개발에 필요한 미생물 위해분석 자료를 확보하기 위해 충북 영동에 소재한 3곳의 복숭아 농장을 대상으로 재배단계별로 총 240점의 시료를 수집하여 미생물 오염도를 조사하였다. 그 결과 일반세균과 대장균군은 모든 시료에서 1.0~7.4 및 0.0~5.4 log CFU/g(or mL, leaf, hand, 100 cm2) 수준으로 검출되었다. 대장균은 240점의 시료 중 농업용수 2점, 복숭아 잎 1점, 작업복 1점, 장갑 1점 등 총 5점의 시료에서 검출되었다. 병원성 미생물은 S. aureus는 작업자 개인위생에서만 0.9 log CFU/hand(or 100 cm2) 이하로 검출되었고, B. cereus는 토양에서 최대 6.4 log CFU/g까지 검출되었으며, L. monocytogenes, E. coli O157:H7 및 Salmonella spp.는 검출되지 않았다. 곰팡이는 모든 시료에서 0.0~5.1 log CFU/g(or mL, leaf, hand, 100 cm2) 범위로 검출되었다.
Air Brake chamber is a core fucntional part delivering the brake force to drum brakes in hybrid commercial trucks. This part needs to have leakage prevention and durability for reliable operation. As an actuator by air pressure, there has to be no air leakeage, and because it is operated with high tention power spring, there has high durable spring head, that contacted power spring directly. In this study, a spring head was designed new size on weak points structually and simulated by structual simulation program. And, a flange and body tighten by clamp ring was simlated structual deformation by assembly torque and inner pressure. As a result, new desgned spring head has structual stablilty over 1.7~14.7% and deformation is in proprotion to inner pressure but the assembly torque of clamp ring is not related to deformation.