• Title/Summary/Keyword: 거시적 모델

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Numerical Discussion on Natural Convection in Soils (지반내 자연대류에 대한 수치해석적 논의)

  • Shin, Hosung
    • Journal of the Korean Geotechnical Society
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    • v.33 no.2
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    • pp.35-47
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    • 2017
  • Thermal behavior of soils is mainly focused on thermal conduction, and the study of natural convection is very limited. Increase of soil temperature causes natural convection due to buoyancy from density change of pore water. The limitations of the analysis using fluid dynamics for natural convection in the porous media is discussed and a new numerical analysis is presented for natural convection in porous media using THM governing equations fully coupled in the macroscopic view. Numerical experiments for thermal probe show increase in the uncertainty of thermal conductivity estimated without considering natural convection, and suggest appropriate experimental procedures to minimize errors between analytical model and numerical results. Burial of submarine power cable should not exceed the temperature changes of $2^{\circ}C$ at the depth of 0.2 m under the seabed, but numerical analysis for high permeable ground exceeds this criterion. Temperature and THM properties of the seafloor are important design factors for the burial of power cable, and in this case effects of natural convection should be considered. Especially, in the presence of heat sources in soils with high permeability, natural convection due to the variation of density of pore water should be considered as an important heat transfer mechanism.

Numerical Study on the characteristics of fire driven flow for smoke ventilation system operating in the deeply underground subway station (대심도 지하역사에서의 화재시 급 배기 동작유무에 따른 열 연기 거동 분석)

  • Jang, Yong-Jun;Kim, Hag-Beom;Lee, Chang-Hyun;Jung, Woo-Sung
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.66-72
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    • 2008
  • In this study, transient 3D numerical simulations were performed to analyze the characteristics of fire driven flow for smoke ventilation system operating conditions in the deeply underground subway station. The smoke flow patterns were compared and discussed under smoke fan operating mode and off mode in the platform. Soongsil Univ. station(line number 7)was chosen for simulation which was the one of the deepest underground subway stations in the each lines of Seoul. The geometry for model is 365m in length include railway, 23.5m for width, 47m for depth. Therefore 10,000,000 structured grids were used for fire simulation. The parallel computational method for fast calculation was employed to compute the heat and mass transfer eqn's with 6 CPUs(Intel 3.0GHz Dual CPU, 12Cores) of the linux clustering machine. The fire driven flow was simulated with using FDS code in which LES method was applied. The Heat release rate was 10MW and The Ultrafast model was applied for the growing model of the fire source.

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A Evaluation Study on Communication of Urban Regeneration for China (중국 도시재생의 의사소통에 관한 평가 연구)

  • Wu, Qian;Hong, Kwan-Seon;He, Shun-Ping
    • The Journal of the Korea Contents Association
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    • v.18 no.12
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    • pp.489-502
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    • 2018
  • The dialogue and interaction among the roles in the urban regeneration process and expanding the social influence of urban regeneration in China are the most important step facing the urban regeneration in China today. Most of the urban regeneration theories in China are manifested only in the macroscopic policy, and the number of researches to resolve urban regeneration problem is far from enough, which can be seen as a realistic problem that confronted by China today as the urban regeneration theory has gone through practice. we analyzed the communication factors that appeared in the case of the communication type urban regeneration. Since 2000. The results of this study show that communicative urban regeneration is suitable for the current state of China. This model can solve the problem of urban regeneration in China with a unique perspective.

Investigating the Trends of Research for the Platform Work (플랫폼노동 연구 동향 분석)

  • Bang, Mi-Hyun;Lee, Young-Min
    • The Journal of the Korea Contents Association
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    • v.21 no.3
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    • pp.430-440
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    • 2021
  • We analyzed research trends of 288 Korean academic dissertations and articles regarding platform work, using topic modeling and keyword network analysis method. Research disciplines of many studies were laws, business administration, and economics fields. Thigh frequent themes were platform labor protection measures and direct or indirect effects of the sharing economy. The main keywords were digital, value, industry, and labor in terms of infrastructure and structural change. Besides, the main topics were the protection of platform workers, the values of sharing services, digital paradigm, and platform regulations. Based on the results of the analysis, we derived four implications and suggestions such as researching structural frames in macroscopic contexts, generalizing case analysis, and technology supplementation by applying average and quantitative analysis methods, researching individual competency development to realize the essential symbiotic value of sustainability, and developing customized vocational education and training programs.

A Study on Information Collection and Idea Creation Using Drones (드론을 활용한 정보수집 및 아이디어 창출에 관한 연구)

  • Jo, Hwani;Yoo, Jaewon;Choi, Hyun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.44 no.1
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    • pp.117-124
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    • 2024
  • The objective of Value Engineering (VE) is to derive the optimal value at the most efficient life cycle cost, comprising three stages: Pre-Study, Study, and Post-Study. In this study, we propose a method for information collection and analysis during planned site visit surveys in the preparation stage of VE. The 3D spatial model, created using a drone, facilitated observation and analysis of the study area from various angles, both from the center and the outside. Additionally, through the utilization of drones, we conducted on-site investigations of the research area's 3D spatial model, enabling a macroscopic perspective previously only feasible through a microscopic viewpoint during planned site visits in the pre-study phase. Furthermore, the utilization of actual spatial data obtained from observations allowed for real-time information verification during Design VE workshops, enhancing the efficiency and reliability of the VE project.

Designing Modularization Method for Digital Twin: Focusing on the Noodle Manufacturing Process (디지털 트윈의 모듈화 기법 설계: 면 제조 공정을 중심으로)

  • Chan Woo Kwon;Seok Hyun Song
    • The Transactions of the Korea Information Processing Society
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    • v.13 no.2
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    • pp.26-33
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    • 2024
  • There has been a recent surge of interest in the Digital Twin technology. The Digital Twin is technique for optimizing objects by simulating physical phenomena or objects through computer-based simulations. Currently, single Digital Twin is being developed to optimize processes limited to specific fields, but there is a limitation in that the independent Digital Twins cannot analyze the vast and complex processes of the real world. To overcome this, the concept of federated Digital Twin has been introduced. To date, the federated Digital Twin research has primarily focused on how to optimize macroscopic objects such as cities. However, by leveraging the interconnected nature of twins, existing implementations of the single Digital Twins can be modularized. In this study, we define the concepts and interrelationships of the single Digital Twin and the federated Digital Twin from a functional perspective related to process optimization and design a modularization technique for the single Digital Twin using the federated Digital Twin. Furthermore, this study aims to discuss the proposed methodology's efficacy by designing a model applying modularization to a real-world fabric manufacturing case.

A Study on Foreign Exchange Rate Prediction Based on KTB, IRS and CCS Rates: Empirical Evidence from the Use of Artificial Intelligence (국고채, 금리 스왑 그리고 통화 스왑 가격에 기반한 외환시장 환율예측 연구: 인공지능 활용의 실증적 증거)

  • Lim, Hyun Wook;Jeong, Seung Hwan;Lee, Hee Soo;Oh, Kyong Joo
    • Knowledge Management Research
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    • v.22 no.4
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    • pp.71-85
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    • 2021
  • The purpose of this study is to find out which artificial intelligence methodology is most suitable for creating a foreign exchange rate prediction model using the indicators of bond market and interest rate market. KTBs and MSBs, which are representative products of the Korea bond market, are sold on a large scale when a risk aversion occurs, and in such cases, the USD/KRW exchange rate often rises. When USD liquidity problems occur in the onshore Korean market, the KRW Cross-Currency Swap price in the interest rate market falls, then it plays as a signal to buy USD/KRW in the foreign exchange market. Considering that the price and movement of products traded in the bond market and interest rate market directly or indirectly affect the foreign exchange market, it may be regarded that there is a close and complementary relationship among the three markets. There have been studies that reveal the relationship and correlation between the bond market, interest rate market, and foreign exchange market, but many exchange rate prediction studies in the past have mainly focused on studies based on macroeconomic indicators such as GDP, current account surplus/deficit, and inflation while active research to predict the exchange rate of the foreign exchange market using artificial intelligence based on the bond market and interest rate market indicators has not been conducted yet. This study uses the bond market and interest rate market indicator, runs artificial neural network suitable for nonlinear data analysis, logistic regression suitable for linear data analysis, and decision tree suitable for nonlinear & linear data analysis, and proves that the artificial neural network is the most suitable methodology for predicting the foreign exchange rates which are nonlinear and times series data. Beyond revealing the simple correlation between the bond market, interest rate market, and foreign exchange market, capturing the trading signals between the three markets to reveal the active correlation and prove the mutual organic movement is not only to provide foreign exchange market traders with a new trading model but also to be expected to contribute to increasing the efficiency and the knowledge management of the entire financial market.

Multi-perspective process modeling (프로세스 모델링을 위한 개념적 틀)

  • 권태형;연광호;최은희
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1995.09a
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    • pp.233-248
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    • 1995
  • 조직변혁(OT:Organizational Tranformation)은 Macro(거시적), Micro(미시 적), Meso(중간적) 관점과 사회적, 기술적 관점을 혼합하여 전체적으로 6가 지의 가능성을 갖는 영역을 생성할 수 있다. 최근 조직 설계와 관련된 많은 연구들은 급변하는 환경에 대한 조직의 반응으로써 기능 중심의 조직설계 대신 Meso관점의 프로세스 중심의 조직 설계를 통한 조직 변혁을 제안해 왔다. 프로세스 재설계 혹은 리엔지니어링과 같은 용어로 등장하는 이 관점 은 서로 다른 연구분야 사이의 상호 연계적 적용을 증가시키고 적절한 자원 할당 및 혼합을 가능하게 함으로써 고객요구와 경쟁력 같은 외부요구사항과 내부적 생산성등을 연계시키고자 한다. 프로세스 모델링은 프로세스 중심의 조직 설계를 통한 조직 변혁의 중요한 도구로 사용될 수 있다. 조직 변혁의 6개 영역과 프로세스의 구성요소 중 일부에만 관심을 갖는 기존의 프로세스 모델링 관점들-기능적 업무(task) 중심의 '기능 관점', 행위적 논리(logic) 중 심의 '행위 관점', 조직적 역할 (roles) 중심의 '조직 관점'-을 반영한 프로세 스 모델은 프로세스 수행목적의 표현과 프로세스 재설계의 기회 발견에 한 계가 있다. 본 연구에서는 프로세스 모델링 기법에 의해 표현되어야 하는 프 로세스 구성요소들을 5W1H를 기준으로 분류하고, 기존 모델링 관점들이 가 지는 한계점의 해결을 위해 두 가지의 새로운 프로세스 모델링 관점-프로세 스 목적과 가치를 표현하는 '정보 관점', 프로세스의 측정에 대한 계량적 정 보를 표현하는 '측정 관점'-을 제시하고, 조직 변혁이 여러 관점들의 통합을 지원하는 프로세스 모델링을 위한 개념적 틀(MPPM)과 프로세스 모델에서 표현되어야 하는 프로세스 구성요소들을 제시하였다.용자 만족도가 보다 높은 것으 로 나타났다. 할 수 있는 효율적인 distributed system를 개발하는 것을 제시하였다. 본 논문은 데이타베이스론의 입장에서 아직 정립되어 있지 않은 분산 환경하에서의 관계형 데이타베이스의 데이타관리의 분류체계를 나름대로 정립하였다는데 그 의의가 있다. 또한 이것의 응용은 현재 분산데이타베이스 구축에 있어 나타나는 기술적인 문제점들을 어느정도 보완할 수 있다는 점에서 그 중요성이 있다.ence of a small(IxEpc),hot(Tex> SOK) core which contains two tempegatlue peaks at -15" east and north of MDS. The column density of HCaN is (1-3):n1014cm-2. Column density at distant position from MD5 is larger than that in the (:entral region. We have deduced that this hot-core has a mass of 10sR1 which i:s about an order of magnitude larger those obtained by previous studies.previous studies.업순서들의 상관관계를 고려하여 보다 개선된 해를 구하기 위한 연구가 요구된다. 또한, 준비작업비용을 발생시키는 작업장의 작업순서결정에 대해서도 연구를 행하여, 보완작업비용과 준비비용을 고려한 GMMAL 작업순서문제를 해결하기 위한 연구가 수행되어야 할 것이다.로 이루어 져야 할 것이다.태를 보다 효율적으로 증진시킬 수 있는 대안이 마련되어져야 한다고 사료된다.$\ulcorner$순응$\lrcorner$의 범위를 벗어나지 않는다. 그렇기

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The Study on Strategy Planning and Outcome of EA in the Public sector (공공부문 EA 추진성과와 발전방안에 관한 연구)

  • Lee, Jae Du;Kim, Eun Ju
    • Journal of Information Technology and Architecture
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    • v.9 no.2
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    • pp.155-166
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    • 2012
  • Recently EA(Enterprise Architecture) has been receiving growing attentions again from the public sectors. It is because EA maturity result is reflected to the organization's informatization level and EA maturity ratio has been enlarged. There has been more participation from the Chief Information Officers of the public sectors. EA research in the public sectors has influenced IT environment since the research started in late '90, the legislation work done in '05, and the maturity model developed in '06. However, there are some remaining tasks to solve. EA policy is introduction oriented, its contribution to the consecutive the best UN e-Government rank is limited, and its user-friendly responding system is still lacking. Related research outcomes are rather microscopic focusing only on the models and maturity than implicating on the public policy in a macroscopic manner. In this respect, this study will provide the implication on how EA policy should be. Requirements derived from EA stakeholders and the tasks will be arranged in accordance with its domain, then the performance and tasks will be demonstrated. As guiding EA stake holders and information related officers to setup the EA policy with these results, this study is expected to support information the policy drivers.

Old Age Early Retirement and Careering Ending Patterns : Centering around the US Older Men (노년기 조기퇴직과 경력마감 형태 : 남성노인을 중심으로)

  • Lee, Hyun-Kee
    • Korean Journal of Social Welfare
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    • v.52
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    • pp.33-61
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    • 2003
  • This study aims to identify early retirement and the subsequent career ending patterns and explain the phenomena in terms of social security policies and labor market perspectives. Although many older workers retire early, there are very few studies to examine how the retirees end their careers after quitting the long-time jobs. The paper investigates individual work experiences 55 through 61, identifies the career ending patterns, constitutes the micro and macro analytical models to estimate the impacts of labor market and work-related variables. The findings show that many older workers have diverse career ending patterns after long-time career jobs, that is, still working at age-55 job, exiting and reentering, sporadic work, retired permanently from age-55 job, a repeat of labor force entry. Also the estimation results indicate that pension, social security, labor market condition, work structure variables better explain the career ending behaviors than social psychological factors of health, education, attitudes toward retirement and job, ethnicity. Finally, this paper discusses theoretical importances of labor market perspectives and policy implications at the end of thesis.

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