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Preparation and Characteristics of Anti-Corrosive Coatings for Steel Structures using Polyaniline (폴리아닐린을 이용한 강 구조물용 방청도료의 제조 및 특성)

  • Kim, Tae-Ok;Kong, Seung-Dae;Park, Jin-U;Hahm, Hyun-Sik
    • Journal of the Korean Applied Science and Technology
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    • v.23 no.3
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    • pp.230-237
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    • 2006
  • Anti-corrosive coatings for steel structures with an alternative anti-corrosive pigment, polyaniline was prepared and anti-corrosive characteristics of the prepared coatings were investigated. The structure of the polyaniline was identified by using FT-IR, UV/Vis. and TGA analysis, and the anti-corrosive properties were analyzed from the results of the salt spray experiment. We found that the anti-corrosion properties of the prepared coatings varied in accordance with the types of primer coating resins as well as with the existence and nonexistence of the top coating. In this condition, the properties of adhesion, chemical resistance, and water resistance were found to be very satisfactory when using the single-packaged urethane resin as the primer coating resin and the urethane resin as the top coating resin.

The Design of Integrated Model On Job Insecurity (고용불안정에 관한 통합모형의 개발)

  • Woo, Chang-Ryeol
    • Korean Business Review
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    • v.21 no.2
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    • pp.17-41
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    • 2008
  • Although job insecurity has attracted many scholars for long time, the research of job insecurity has not been accumulated because of nonexistence of and comprehensive and systematic model on job insecurity. This study, therefore, has provided integrated model of job insecurity and has also generated important propositions of job insecurity. This study aims to design the antecedents and consequences(outcomes) of job insecurity of employees. First, we have postulated important hypothesis based on the existing literatures. Second, we have tested hypothesis by the comprehensive review of existing local empirical studies. Third we have provided underlying logics of designing integrated model of job insecurity. And we have also generated Important propositions underlying the model focusing on job insecurity. We propose that employees' job insecurity increase with their expectation about further organizational change, role ambiguity. We also propose that employees' job insecurity raise their psychological strain while reducing their organizational commitment, job satisfaction and work effort. Theoretical implications are discussed, as are the implications of study and suggestions for future research.

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A Decision Methodology for the Priority of Military Facility Remodeling (군 시설 리모델링의 우선순위 결정 방법)

  • Yang In-Cheul;Jeon Yong-Seok;Park Chan-Sik
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • autumn
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    • pp.406-409
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    • 2003
  • The procedure of present military facility remodeling has many problems at the stage of evaluating the priorities in various remodeling projects which have been caused from lots of corps. These problems have usually happened not only because of the shortage of the cooperation system in the related divisions but also because of the nonexistence of the effective process and method for evaluating the priorities. I've reviewed the study of remodeling and military facility business and applied the AHP(Analytic Hierarchy Process) method which is effective to evaluate the priorities in various groups' decision.

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Development of Heterarchical SFCS Execution Module using E-Net (E-Net을 이용한 Heterarchical SFCS 실행 모듈 개발)

  • Hong, Soon-Do;Cho, Hyun-Bo;Jung, Moo-Young
    • Journal of Korean Institute of Industrial Engineers
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    • v.25 no.1
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    • pp.87-99
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    • 1999
  • A shop floor control system(SFCS) performs the production activities required to fill orders. In order to effectively control these activities, the autonomous agent-based heterarchical shop floor control architecture is adopted where a supervisor does not exist. In this paper, we define functional perspective of the heterarchical shop floor control using planning, scheduling, and execution modules. In particular, we focus on an execution module that can coordinate the planning and scheduling modules and a general execution module that easily can be modified to execute the other equipment. The execution module can be defined informally as a module that downloads and performs a set of scheduled tasks. The execution module is also responsible for identifying and resolving various errors whether they come from hardware or software. The purpose of this research is to identify all the execution activities and solving techniques under the assumptions of the heterarchical control architecture. And we model the execution module in object-oriented modelling technique for generalization. The execution module modeled in object-oriented concept can be adopted to the other execution module easily. This paper also proposes a classification scheme for execution activities of the heterarchical control architecture. Petri-nets are used as a unified framework for modeling and controlling execution activities. For solving the nonexistence of a supervisor, a negotiation-based solution technique is utilized.

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The Performance of Insulation of Noise by Air between Floors According to Structure Systems of Apartment (공동주택 구조형태별 층간 공기전달음 차단 성능)

  • Lee, Byung-Kwon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.05a
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    • pp.1152-1155
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    • 2007
  • Lately concerns about structure have been increased by advantages of floor impact noise, poilitical induction and changeability. Hence, Flat Plate Structure has been constructed increasingly. This study shows the comparison of the performance of sound insulation of Flat Plate Structure System and the existing Wall Structure. For this study, taking the same level organization of Daelim Architectural Environmental Research Center, I found the performance of sound insulation between the upper and lower floors about Wall Structure and Flat Plate Structure. Consequently, the performance of sound insulation between upper and lower floors of Flat Plate Structure was 3-5dB higher was approximately 3-5dB higher than one of Wall Structure. Especially, the performance of sound insulation on the upper floor was 1-3dB higher than on the lower floor. In addition, as the result of comparing radiation sound which radiates from the wall of lower floors with each structure system, Flat Plate Structure was about 4dB higher with Rw than Wall Structure. As we see totally, the performance of sound insulation of Flat Plate Structure is highter than one of the Wall Structure. It is 3-5dB higher and the main reason for this result depends on the existence of the wall which can radiate sound and nonexistence.

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Toxic Concept in Oriental Medicine (전통적인 한의학(韓醫學)의 독성(毒性) 개념)

  • Lee Sun-Dong
    • Journal of Society of Preventive Korean Medicine
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    • v.3 no.1
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    • pp.157-172
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    • 1999
  • This treatise, after review recent data on Oriental Medical toxicity, gets a conclusion on toxic concept of Oriental Medicine. 1. In the oriental medicine, the concept of toxic character contains propensity which disposition is inclined, and general meaning covered with the effect of a medicine, a side effect, formation of a medicine Besides, the concept diversely is used in the cause of a disease, names, symptoms, how to treat, medicines, prevention name, etc. 2. Every herbal drugs has toxic character. Levels of toxicity are nonexistence(無毒), existence(有毒), a little(小毒), always(常毒), serious(大毒), fatal toxic(劇毒), whose concepts in the Oriental Medicine are divided relative and absolute at the same time. 3. The examples of the fatal events by poisoning up to now are more than 400 cases(in China). 4. The factors of toxicity are the amount used unsuitably, the combination, directions, and interactions between western and oriental medicine, etc. The reduction of toxicity and how to detoxicate is several methods. The toxic science in Oriental Medicine based on the formation of oriental medicine present principles which use herbal drugs safely and availablely, utilizing th dispositions and efficiencies. It has positive, learning spirits which prevent abuse of oriental medicine, and which exactly diagnose and use the herbal drugs in the treatment with absolute toxic medicine. However, I think that scientific, positive experimental research is necessary to setup dose-response relation, be in relative quantity of toxic character, operate on the reactive mechanism exactly.

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A petri-net based execution model of processing equipment for CSCW-based shop floor control in agile manufacturing

  • Hong, Soondo;Cho, Hyuenbo;Jung, Mooyoung
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1995.04a
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    • pp.193-200
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    • 1995
  • A shop floor control system(SFCS), a central part of agile manufacturing, performs the production activities required to fill orders. In order to effectively control these activities, CSCW (computer supported cooperative work) is adopted where a supervisor does not exist. In this paper, we define functional perspective of CSCW-based shop floor control using planning, scheduling, and execution functions. In particular, we focus on an execution model that can coordinate the planning and scheduling functions. Execution can be defined informally as a function that downloads and performs a set of scheduled tasks. Execution is also responsible for identifying and resolving various errors whether they come from hardware or software. The purpose of this research is to identify all the execution activities and solving techniques under the assumptions of CSCW-based heterarchical control architecture. This paper also proposes a classification scheme for execution activities of CSCW-based heterarchical control architecture. Petri-nets are used as a unified framework for modeling and controlling execution activities. For solving the nonexistence of a supervisor, A negotiation-based solution technique is utilized.

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EIGENVALUE PROBLEMS FOR p-LAPLACIAN DYNAMIC EQUATIONS ON TIME SCALES

  • Guo, Mingzhou;Sun, Hong-Rui
    • Bulletin of the Korean Mathematical Society
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    • v.46 no.5
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    • pp.999-1011
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    • 2009
  • In this paper, we are concerned with the following eigenvalue problems of m-point boundary value problem for p-Laplacian dynamic equation on time scales $(\varphi_p(u^{\Delta}(t)))^\nabla+{\lambda}h(t)f(u(t))=0,\;t\in(0,T)$, $u(0)=0,\varphi_p(u^{\Delta}(T))=\sum\limits_{i=1}^{m-2}a_i\varphi_p(u^{\Delta}(\xi_i))$, where $\varphi_p(u)=|u|^{p-2}$u, p > 1 and $\lambda$ > 0 is a real parameter. Under certain assumptions, some new results on existence of one or two positive solution and nonexistence are obtained for $\lambda$ evaluated in different intervals. Our work develop and improve many known results in the literature even for the continual case. In doing so the usual restriction that $f_0=lim_{u{\rightarrow}0}+f(u)/\varphi_p(u)$ and $f_\infty = lim_{u{\rightarrow}{\infty}}f(u)/\varphi_p({u})$ exist is removed. As an applications, an example is given to illustrate the main results obtained.

QUALITATIVE PROPERTIES OF WEAK SOLUTIONS FOR p-LAPLACIAN EQUATIONS WITH NONLOCAL SOURCE AND GRADIENT ABSORPTION

  • Chaouai, Zakariya;El Hachimi, Abderrahmane
    • Bulletin of the Korean Mathematical Society
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    • v.57 no.4
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    • pp.1003-1031
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    • 2020
  • We consider the following Dirichlet initial boundary value problem with a gradient absorption and a nonlocal source $$\frac{{\partial}u}{{\partial}t}-div({\mid}{\nabla}u{\mid}^{p-2}{\nabla}u)={\lambda}u^k{\displaystyle\smashmargin{2}{\int\nolimits_{\Omega}}}u^sdx-{\mu}u^l{\mid}{\nabla}u{\mid}^q$$ in a bounded domain Ω ⊂ ℝN, where p > 1, the parameters k, s, l, q, λ > 0 and µ ≥ 0. Firstly, we establish local existence for weak solutions; the aim of this part is to prove a crucial priori estimate on |∇u|. Then, we give appropriate conditions in order to have existence and uniqueness or nonexistence of a global solution in time. Finally, depending on the choices of the initial data, ranges of the coefficients and exponents and measure of the domain, we show that the non-negative global weak solution, when it exists, must extinct after a finite time.

A Study on the Moment-Curvature Relation of Hollow RC piers considering Tension Stiffening Effect (인장강성효과를 고려한 중공단면 교각의 모멘트-곡률 관계에 대한 연구)

  • Park Young Ho;Kim Se Hun;Choi Seung Won;Oh Byung Hwan
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.11a
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    • pp.17-20
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    • 2005
  • Moment-curvature relation of RC pier is influenced greatly in occurrence form of crack and difference is happened according to consideration existence and nonexistence of tension stiffening effect. However, studies considering these is very insufficient misgovernment. Also, it is sometimes unavoidable lap splice of axial reinforcement in plastic hinge region of RC piers. However, specific design standard about lap splice of axial reinforcement is unprepared real condition and study about effect that lap splice of axial reinforcement get in occurrence form of crack is insufficient misgovernment. Therefore, in this paper, experiments are performed with hollow RC piers that do lap splice of axial reinforcement by main variable. And this study present analytical method about moment-curvature relation of hollow RC pier that consider tension stiffening effect and analyze effect that lap splice of axial reinforcement gets in occurrence form of crack. Analytic method of moment-curvature relation of RC pier that present in this study shows very similar motion with experiment result and crack interval of RC pier is suffering dominate impact in the augmented reinforcement amount by lap splice and average crack interval decreases as lap splice ratio increases.

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