• Nuclear Engineering and Technology
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• v.51 no.6
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• pp.1616-1625
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• 2019

Measuring occurrence times of random events, aimed to determine the statistical properties of the governing stochastic process, is a basic topic in science and engineering, and has been the subject of numerous mathematical modeling approaches. Often, true statistical properties deviate from measured properties due to the so called dead time phenomenon, where for a certain time period following detection, the detection system is not operational. Understanding the dead time effect is especially important in radiation measurements, often characterized by high count rates and a non-reducible detector dead time (originating in the physics of particle detection). The effect of dead time can be interpreted as a suitable rarefied sequence of the original time sequence. This paper provides a limit theorem for a high rate (diffusion-scale) counter with extendable (Type II) dead time, where the underlying counting process is a renewal process with finite second moment for the inter-event distribution. The results are very general, in the sense that they refer to a general inter arrival time and a random dead time with general distribution. Following the theoretical results, we will demonstrate the applicability of the results in three applications: serially connected components, multiplicity counting and measurements of aerosol spatial distribution.

• Korean Journal of Construction Engineering and Management
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• v.7 no.2 s.30
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• pp.89-97
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• 2006

With the increased demand on housing quality and effective urban redevelopment, a new paradigm in reconstruction project is in need. Especially, the Urban and Residential Environment Improvement Law which initiated on July 1, 2003 has become a significant turning point. This code is expected to function as a consistent and systematic measure. This study will examine the code's major concepts and methods to progress reconstruction projects effectively. The application of construction management is examined carefully since the new code requires renewal project consulting firms to function as a professional complement rather than simply perform administration work, as in the past. Also, construction managing methods that can be related to renewal project consulting are examined and speculated. Lastly, methods to improve efficiency in reconstruction projects are introduced through case study and analysis on applicability and expected results.

• Molecules and Cells
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• v.46 no.12
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• pp.727-735
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• 2023

Stem cells require high amounts of energy to replicate their genome and organelles and differentiate into numerous cell types. Therefore, metabolic stress has a major impact on stem cell fate determination, including self-renewal, quiescence, and differentiation. Lysosomes are catabolic organelles that influence stem cell function and fate by regulating the degradation of intracellular components and maintaining cellular homeostasis in response to metabolic stress. Lysosomal functions altered by metabolic stress are tightly regulated by the transcription factor EB (TFEB) and TFE3, critical regulators of lysosomal gene expression. Therefore, understanding the regulatory mechanism of TFEB-mediated lysosomal function may provide some insight into stem cell fate determination under metabolic stress. In this review, we summarize the molecular mechanism of TFEB/TFE3 in modulating stem cell lysosomal function and then elucidate the role of TFEB/TFE3-mediated transcriptional activity in the determination of stem cell fate under metabolic stress.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.28 no.2
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• pp.63-72
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• 2016

An expected-discounted cost model based on RRP(Renewal Reward Process), referred to as a stochastic decision model, has been developed to estimate the optimal period of in-depth inspection which is one of critical issues in the life-cycle maintenance management of harbor structures such as rubble-mound breakwaters. A mathematical model, which is a function of the probability distribution of the service-life, has been formulated by simultaneously adopting PIM(Periodic Inspection and Maintenance) and CBIM(Condition-Based Inspection and Maintenance) policies so as to resolve limitations of other models, also all the costs in the model associated with monitoring and repair have been discounted with time. From both an analytical solution derived in this paper under the condition in which a failure rate function is a constant and the sensitivity analyses for the variety of different distribution functions and conditions, it has been confirmed that the present solution is more versatile than the existing solution suggested in a very simplified setting. Additionally, even in that case which the probability distribution of the service-life is estimated through the stochastic process, the present model is of course also well suited to interpret the nonlinearity of deterioration process. In particular, a MCS(Monte-Carlo Simulation)-based sample path method has been used to evaluate the parameters of a damage intensity function in stochastic process. Finally, the present stochastic decision model can satisfactorily be applied to armor units of rubble mound breakwaters. The optimal periods of in-depth inspection of rubble-mound breakwaters can be determined by minimizing the expected total cost rate with respect to the behavioral feature of damage process, the level of serviceability limit, and the consequence of that structure.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.61-64
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• 2003

A band function model paired comparison method (BMPC method) is a kind of a paired comparison methods. Considering the human ambiguities, the BMPC method expressing the human judgment characteristics as a monotonous increase function with some width. Since function types are not specified in a BMPC method, the solution is obtained from inequalities, and the solution is given as a domain. To solve the simultaneous inequalities, the sequential renew method is used in the previous BMPC method. However, the sequential renew method requires much computational effort and memories. Generally, in BMPC method, it is able to solve only a paired comparison table which has less 12-13 samples. For that purpose, a new fast solution algorithm is required. In this paper, we proposed a new “search vector method” which renews the solution domain without creating new edge vectors. By using the method, it is able to decrease the necessary memory spaces and time to solve. The proposed method makes it able to solve more than 15 samples paired comparison inspections which are impossible to solve by previous method.

• Journal of Navigation and Port Research
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• v.44 no.5
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• pp.430-437
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• 2020

This paper analyzes the profitability of the Private Finance Initiative(PFI) ports and proposes the application plans of the R-project(Rehabilitate project) for old ports to attract and activate private investment in the port industry. The R-project of old ports can reduce the government's financial budget and provide improved facilities for users more quickly than the public sector comparator. Before suggesting the R-project for old ports, the profitability of the currently operating 11 companies of the PFI ports are analyzed using the four ratios of profitability, and the results show that all the companies indicate low profitability, except for the top three companies. To apply the R-project, the three types of R-project ports are categorized as maintaining the function of the port, changing the function of the port, and mixing the function of the port. Additionally, three obstacles and improvement measures are suggested; attracting private business, legal issues, and administrative procedures. This study is conducive to the policy making for the port renewal and the activating PFI for the port industry.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.6
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• pp.1346-1352
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• 2009

Warranty cost of automobile parts varies depending on the parts failure rate in a warranty region of individual markets. Parts failure rate is significantly affected by usage-rate given that other stressors of individual markets are similar. Accordingly, warranty cost can be predicted by failure modeling which reflects usage-rate and using a stochastic process. In this paper, one-dimensional approach is used by applying accelerated failure time model on the assumption that the usage-rate is linear. Such model can explain changes in parts failure rate depending on the changes in usage-rate since it can be expressed as a function of usage-rate. Therefore, acquisition of usage-rate in a new market will automatically lead to estimate of failure rate even without warranty data and warranty cost of parts can be predicted through a renewal process in replacement cases. A case study using warranty data of two real markets is presented in the application part of this paper.

• Journal of the Korean Institute of Landscape Architecture
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• v.13 no.2
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• pp.13-26
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• 1985

^x The enviroment defines the living conditions for people and has at the same time the possibility to create new environment. In Korea, where the rate of urbanization reached more than 50% in 1970′s the priority has been put on the economic development and administrative function. Under the circumstance, visual environmental field was dealt lightly and it resulted in undesirable environment. The techniques of Mordern Arts (Montage, Depeysment, Tromp L′oeil, P.O.P Art, etc.) helped Super Graphics appear in the urban areas. Environmental Art has been expended into the public space and people came to recognize the Arts as the "Street Art" or "Street as Gallery". Super Graphics has four types 1) Resident′s Super Graphics ; Minority groups came to maintain social equality and rights, in cooperation with each other. Such maintenance required general urbanites to form communities which gave birth to the community art, Mural Painting. 2) Environmental Super Graphics ; Beauty has come to be stressed in order to improve the quality of urban lives in the course of inescapable urban development. Instead of renewal of all established construction conservation oriented renewal was encouraged. 3) Super Graphics as Population Arts ; In the 1960′s artists repulsed the establishments in an efforts to open new phase independent from the expressional in the arts. They recognized the relationship between painting, society and the public in different angle and tried to describe all living space on canvas. 4) Super Graphics as Advertisement ; Super Graphics functions as efficient media to deliver images to the urbanites. Super Graphics as media plays the role for political propaganda and commercial advertisements according to their purposes. In Korea, especially, it is required to introduce the environmental Super Graphics. But it is desirable to introduce Super Graphics with Korean culture and sense of beauty. Designers themselves are also required to have responsibility to improve the quality of urban culture.

• Journal of the Korea Society for Simulation
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• v.20 no.4
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• pp.31-40
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• 2011

Sensor nodes are easily exposed to malicious attackers by physical attacks. The attacker can generate various attacks using compromised nodes in a sensor network. The false report generating application layers injects the network by the compromised node. If a base station has the injected false report, a false alarm also occurs and unnecessary energy of the node is used. In order to defend the attack, a statistical en-route filtering method is proposed to filter the false report that goes to the base station as soon as possible. A path renewal method, which improves the method, is proposed to maintain a detection ability of the statistical en-route filtering method and to consume balanced energy of the node. In this paper, we proposed the secure path cycle method to consume effective energy for a path renewal. To select the secure path cycle, the base station determines through hop counts and the quantity of report transmission by an evaluation function. In addition, three methods, which are statistical en-route filter, path selection method, and path renewal method, are evaluated with our proposed method for efficient energy use. Therefore, the proposed method keeps the secure path and makes the efficiency of energy consumption high.

• Journal of the Daesoon Academy of Sciences
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• v.17
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• pp.173-196
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• 2004

Miroku belief observed in Japanese folklore and popular religions is originated from the faith in a bodhisattva called Miroku (Maitreya) who, depending on Buddhist account, is supposed to appear in this world to save all mankind. This faith, together with the millenarianism inherent in it, was disseminated into many areas of East and Southeast Asia. It developed in various ways, being associated with the religious tradition of each area where it was accepted. In Japanese folklore and popular religions the aspiration for the "World of Miroku", the ideal world expected to be realized in the future, has been its most notable feature. This paper examines the notion of the "World of Miroku" developed in the cult of Mount Fuji in early modern Japan. In particular this paper focuses on the "World of Miroku" appearing in the teachings of Fuji-ko and Fujido, which were the organizations of lay believers. Through the examination this paper made the following facts clear. (1) The notion of the "World of Miroku" developed by Fuji-ko and Fujido had its bases in Miroku belief of Japanese folklore. (2) However the notion of the "World of Miroku" in the teachings of Fuji-ko and Fujido was quite different from that of the folklore. While the "World of Miroku" appearing in the folklore is characterized by good harvest and abundant gold and silver, Fuji-ko and Fujido leaders thought that all people, including the emperor and the shogun, would earnestly carry out their house business, do their best to promote the happiness of the others, and pray for the salvation of all mankind in the "World of Miroku". (3) The notion about the changes of the world, which was particular to Fuji-ko and Fujido, accounts for such development in the concept of the "World of Miroku". According to the notion the current world was recognized as the second stage, between the original world in the past and the "World of Miroku" in the future, in the history of human beings. This idea helped the leaders of Fuji-ko and Fujido to develop the theories of world renewal, in which the wrong doings of the rulers and poor morality of the people were to be corrected in the "World of Miroku". (4) One of the most important features of the "World of Miroku" was the equality between men and women according to the teachings of Fujido. Both Fuji-ko and Fujido had opposed to the prevailing view of women, in which women were regarded as being sinful and polluted. Fujido further tried to improve the status of women in their families and the society. (5) In accordance with such an innovatory view, Fujido challenged the custom of excluding women from sacred places, Mount Fuji in particular. Through clarifying these facts this paper shows that Miroku belief could function as a basis for developing the ideas concerning the world renewal in early modern Jap