• Title/Summary/Keyword: Uncertain Process

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COVID-19 and the Korean Economy: When, How, and What Changes?

  • Park, ChangKeun;Park, JiYoung
    • Asian Journal of Innovation and Policy
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    • v.9 no.2
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    • pp.187-206
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    • 2020
  • Under the on-going evolution of the COVID-19 pandemic, estimating the economic impact of the pandemic is highly uncertain and challenging. This situation makes it difficult for policymakers, governors, and economic entities to formulate appropriate responses and decision makings. To provide useful information about the effect of the COVID-19 pandemic on the Korean economy, this study examined macroeconomic impact analysis stemming from the pandemic shocks with different scenarios for the Korean economy. Based on three scenarios using the growth rate of 2020 GDP and consumer expenditure patterns, the 2021 GDP by industry sector was forecast with two new approaches. First, the recovering process of the Korean economy from the shock was analyzed by applying a Flex-IO method. Second, a new forecasting approach combined with an IO coefficient matrix was applied to forecast the future GDP changes. The findings of this study are summarized as follows: First, the total GDP growth rate under the Pessimistic Scenario demonstrates less rebound from the shock than that of the Base Scenario. Second, agriculture, culture, and tourism-related sectors that are suffering from the severe losses of COVID-19 showed lower resilience than other different industries. Third, information and communications technology (ICT) industry maintains a stable growth trend and is expected to take the leading role for the Korean economy in the post-COVID-19 and the Industry 4.0 eras. The findings deliver that it needs to analyze how government expenditure responding the shock into the forecasting model, which can be more useful and reliable to simulate the resilience from the pandemic.

Rethinking of the Uncertainty: A Fault-Tolerant Target-Tracking Strategy Based on Unreliable Sensing in Wireless Sensor Networks

  • Xie, Yi;Tang, Guoming;Wang, Daifei;Xiao, Weidong;Tang, Daquan;Tang, Jiuyang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.6 no.6
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    • pp.1496-1521
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    • 2012
  • Uncertainty is ubiquitous in target tracking wireless sensor networks due to environmental noise, randomness of target mobility and other factors. Sensing results are always unreliable. This paper considers unreliability as it occurs in wireless sensor networks and its impact on target-tracking accuracy. Firstly, we map intersection pairwise sensors' uncertain boundaries, which divides the monitor area into faces. Each face has a unique signature vector. For each target localization, a sampling vector is built after multiple grouping samplings determine whether the RSS (Received Signal Strength) for a pairwise nodes' is ordinal or flipped. A Fault-Tolerant Target-Tracking (FTTT) strategy is proposed, which transforms the tracking problem into a vector matching process that increases the tracking flexibility and accuracy while reducing the influence of in-the-filed factors. In addition, a heuristic matching algorithm is introduced to reduce the computational complexity. The fault tolerance of FTTT is also discussed. An extension of FTTT is then proposed by quantifying the pairwise uncertainty to further enhance robustness. Results show FTTT is more flexible, more robust and more accurate than parallel approaches.

Design of reference model for model reference sliding model control (모델 기준 슬라이딩 모드 제어기의 기준 모델 설계)

  • Byun, Kyung-Seok
    • Journal of the Institute of Convergence Signal Processing
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    • v.8 no.4
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    • pp.297-306
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    • 2007
  • Model reference control is control method such that overall response of a plant plus controller approaches that of a given reference model. The reference model provides desired trajectory the plant should follow. There are many kinds of control methods in MRC. However, this paper focuses on Model Reference Sliding Mode Control. The plant of these controls is an uncertain and linear system varying in time, of second order, and with SISO. In this paper, a design scheme of reference model is proposed for MRSMC. The scheme determines reference model based on the information on bounded control inputs, reference inputs and system parameters. It is used to choose a Fixed Reference Model in the process of controller design, to update Variable Reference Model when stepwise reference inputs change and to update Instant Reference Model at every sampling time. The simulation results show that the proposed method yields better control performance than the conventional MRC subject to the stepwise reference input when applied to the position control system for motor system.

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An Analysis of the Importance of the Risk Factors Influencing the Calculation of the Subcontract Construction Bidding Cost (건설공사 하도급 입찰단가 산정에 영향을 미치는 리스크 요인의 중요도 분석)

  • Lee, Sung-Goo;Park, Tae-Keun
    • Korean Journal of Construction Engineering and Management
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    • v.8 no.2
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    • pp.109-117
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    • 2007
  • The construction environment has the trend of oversizing and professionalizing, the increase of the construction period, and the risk factors and the uncertain factors which are important in the construction bid. The misunderstanding and the lack of knowledge of the subcontractor result in the decrease of the profit or the deficit. In conclusion, these are supposed to give the financial burden to the subcontractor. So, it is very important to predict the construction preparation cost calculation by the risk factors in the bidding stage and to calculate the bid unit cost considering the target profit of the subcontractor in the process of the mutual agreement and performance of the contract. In these points of view, this study analyzes how the importance of the risks influencing the bidding cost calculation affect the construction cost, and this analysis can be used as the basic data to establish the suitable bid strategy of the subcontractor.

ESD(Education for Sustainable Development) and ESE(Education for Sustainability & Its Economy) -EE and Its Boundary for Co-conceptional Approach to Sustainability- (지속가능발전을 위한 교육(ESD)과 지속가능성을 위한 (경제)교육 -<지속가능성>의 개념 공유를 위한 환경교육과 그 범위-)

  • Kim, Tae-Kyung
    • Hwankyungkyoyuk
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    • v.19 no.3
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    • pp.67-79
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    • 2006
  • Education for Sustainable Development(ESD) is inclined to become popular topics in EE related debates, almost similar to populism, with declaration of UNESCO's Decade OF ESD (DESD). However we can't avoid that development in ESD practically means economic linear progress. Basically UN's declaration is to accomplish worldly task on human civilization, social & environmental problems, including ESSD. ESD is also important means for practicing ESSD, which has proved to be failure since Brutrant Report, owing to uncertain recognition of sustainability which should be something figured out by their surrounding circumstance or the conditions following its community culture, all same around the world. In this circumstance, we need certain identification on ESD globally recognized, no matter with the developing level of economy. But sustainability is usually managed or controlled by economically powered countries, by improving relatively under-development countries's economic conditions for equity. They believe under-development countries's env. problems can't be resolved without securing of economic equity. Under-development countries's economic equity can be come true ? even by another economic super powers. It really means just controlling or management by them. These all controlling process can't secure under-development countries's sustainability. Because it is not something just controlled, characterized as growing up by self-supporting system of ethnic or regional communities. So identification of sustainability in here is , not . Following its identification, we should discuss ESD, and furthermore for real ESD, there is powerful need to change it into ESE (Education for Sustainability & its Economy) to reflect this co-conceptional approach to ESD. And also we need to distinguish the educational contents boundaries among ESD and EE for this. Basically existing EE has been dealing with pollution-oriented or its related social comprehensive subjects, so it seems that EE is not familiar and harmony with ESD contents, however in alternative case I propose in this paper, changing into ESE, it could include almost all of ESD subjects, furthermore practically EE might be same with ESE.

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A Clinical Study of the Treatment Prescribed Kalkunhaeki-tang for FUO (Fever of Unknown Origin) Patient (원인 불명열 환자를 갈근해기탕(葛根解肌湯)으로 치험한 1례)

  • Yim, Chi-Hye;Cho, Jae-Seung;Kim, Hyo-Soo;Kwon, Seung-Man;Kim, Shin;Kim, Il-Hwan;Park, Hye-Sun
    • Journal of Sasang Constitution and Immune Medicine
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    • v.19 no.2
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    • pp.223-229
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    • 2007
  • 1. Objectives FUO is defined as a temperature higher than $38.3^{\circ}C$ on several occasions and lasting longer than 3 weeks, with a diagnosis that remain uncertain after 1 week of investigation. Diagnosing the cause of FUO is particularly difficult. 2. Methods We have tried researching effect of herbal medicines(Kalkunhaeki - tang treatments) and Acupoint Injection to Taeumin FUO patient. 3. Results A Taeumin patient diagnosed to FUO was treated with Taeumin herbal medicines(kalkunhaeki - tang treatments) and change of patient's fever and general condition were improved. 4. Conclusions The constitutional treatment with Kalkunhaeki - tang may have an effect on management of FUO. So we report the healing process and results of this patient in this study.

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Reasoning Occluded Objects in Indoor Environment Using Bayesian Network for Robot Effective Service (로봇의 효과적인 서비스를 위해 베이지안 네트워크 기반의 실내 환경의 가려진 물체 추론)

  • Song Youn-Suk;Cho Sung-Bae
    • Journal of KIISE:Computing Practices and Letters
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    • v.12 no.1
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    • pp.56-65
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    • 2006
  • Recently the study on service robots has been proliferated in many fields, and there are active developments for indoor services such as supporting for elderly people. It is important for robot to recognize objects and situations appropriately for effective and accurate service. Conventional object recognition methods have been based on the pre-defined geometric models, but they have limitations in indoor environments with uncertain situation such as the target objects are occluded by other ones. In this paper we propose a Bayesian network model to reason the probability of target objects for effective detection. We model the relationships between objects by activities, which are applied to non-static environments more flexibly. Overall structure is constructed by combining common-cause structures which are the units making relationship between objects, and it makes design process more efficient. We test the performance of two Bayesian networks for verifying the proposed Bayesian network model through experiments, resulting in accuracy of $86.5\%$ and $89.6\%$ respectively.

Effectual Fuzzy Query Evaluation Method based on Fuzzy Linguistic Matrix in Information Retrieval (정보검색에서 퍼지 언어 매트릭스에 근거한 효율적인 퍼지 질의 평가 방법)

  • 최명복;김민구
    • Journal of the Korean Institute of Intelligent Systems
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    • v.10 no.3
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    • pp.218-227
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    • 2000
  • In this paper, we present a new fuzzy information retrieval method based on thesaurus. In the proposed method th thesaurus is represented by a fuzzy linguistic matrix, where the elements in fuzzy linguistic matrix represent a qualitative linguistic values between terms. In the fuzzy linguistic matrix, there are three kinds of fuzzy relationships between terms, i.e., similar relation, hierarchical relation, and associative relation. The implicit fuzzy relationships between terms are inferred by the transitive closure of the fuzzy linguistic matrix based on fuzzy theory. And the proposed method has the capability to deal with a qualitative linguistic weights in a query and in indexing of information items to reflect qualitative measure of human based on vague and uncertain decisions rather than a quantitiative measure. Therefore the proposed method is more flexible than the ones presented in papers[1-3]. Moreover our method is more effectual of time than the ones presented in papers[1-3] because we use a fuzzy linguistic matrix and AON (Associate Ordinary Number) values in query evaluation process. As a result, the proposed method allows the users to perform fuzzy queries in a more flexible and more intelligent manner.

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Archival Description and Access in Digital Age that Focuses on the Practices of The National Archives' (디지털 시대의 기록물 기술과 접근 - The National Archives 사례를 중심으로 -)

  • Park, Zi-young
    • Journal of Korean Society of Archives and Records Management
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    • v.17 no.4
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    • pp.87-107
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    • 2017
  • Because of the creation and transfer of born-digital records, file unit-based record description practices have changed fundamentally. In this study, we analyzed the archival description practices of The National Archives (TNA) to maintain intellectual control in the digital records management environment and to support the access to records of users. TNA has created an archival description based on ISAD(G) but, for describing born-digital records, it changed the guideline for descriptive cataloging practices. As the method of ISAD(G) cannot adhere to born-digital records, the next-generation descriptive standard, Records in Contexts (RiC), is still being developed by ICA. In addition to international efforts, we need to build an archival description system that fits our environment, especially because since the year 2000, TNA's online cataloging system has changed and ISAD(G) has been modified in this process. This study also proposed continuous monitoring of digital archival descriptions, provides an integrated approach to analog records and digital content and strengthens experimentation and cooperation toward an uncertain digital future.

Tracking Position Control of DC Servo Motor in LonWorks/IP Network

  • Song, Ki-Won;Choi, Gi-Sang;Choi, Gi-Heung
    • International Journal of Control, Automation, and Systems
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    • v.6 no.2
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    • pp.186-193
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    • 2008
  • The Internet's low cost and ubiquity present an attractive option for real-time distributed control of processes on the factory floor. When integrated with the Internet, the LonWorks open control network can give ubiquitous accessibility with the distributed control nature of information on the factory floor. One of the most important points in real-time distributed control of processes is timely response. There are many processes on the factory floor that require timely response. However, the uncertain time delay inherent in the network makes it difficult to guarantee timely response in many cases. Especially, the transmission characteristics of the LonWorks/IP network show a highly stochastic nature. Therefore, the time delay problem has to be resolved to achieve high performance and quality of the real-time distributed control of the process in the LonWorks/IP Virtual Device Network (VDN). It should be properly predicted and compensated. In this paper, a new distributed control scheme that can compensate for the effects of the time delay in the network is proposed. It is based on the PID controller augmented with the Smith predictor and disturbance observer. Designing methods for output feedback filter and disturbance observer are also proposed. Tracking position control experiment of a geared DC Servo motor is performed using the proposed control method. The performance of the proposed controller is compared with that of the Internal Model Controller (IMC) with the Smith predictor. The result shows that the performance is improved and guaranteed by augmenting a PID controller with both the Smith predictor and disturbance observer under the stochastic time delay in the LonWorks/IP VDN.