• Title/Summary/Keyword: Potential Problem

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Determination of Unit Hydrograph for the Hydrological Modelling of Long-term Run-off in the Major River Systems in Korea (장기유출의 수문적 모형개발을 위한 주요 수계별 단위도 유도)

  • 엄병현;박근수
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.26 no.4
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    • pp.52-65
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    • 1984
  • In general precise estimation of hourly of daily distribution of the long-term run-off should be very important in a design of source of irrigation. However, there have not been a satisfying method for forecasting of stationar'y long-term run-off in Korea. Solving this problem, this study introduces unit-hydrograph method frequently used in short-term run-off analysis into the long-term run-off analysis, of which model basin was selected to be Sumgin-river catchment area. In the estimation of effective rainfall, conventional method neglects the Soil moisture condition of catchment area, but in this study, the initial discharge (qb) occurred just before rising phase of the hydrograph was selected as the index of a basin soil moisture condition and then introduced as 3rd variable in the analysis of the reationship between cumulative rainfall and cumulative loss of rainfall, which built a new type of separation method of effective rainfall. In next step, in order to normalize significant potential error included in hydrological data, especially in vast catchment area, Snyder's correlation method was applied. A key to solution in this study is multiple correlation method or multiple regressional analysis, which is primarily based on the method of least squres and which is solved by the form of systems of linear equations. And for verification of the change of characteristics of unit hydrograph according to the variation of a various kind of hydrological charateristics (for example, precipitation, tree cover, soil condition, etc),seasonal unit hydrograph models of dry season(autumn, winter), semi-dry season (spring), rainy season (summer) were made respectively. The results obtained in this study were summarized as follows; 1.During the test period of 1966-1971, effective rainfall was estimated for the total 114 run-off hydrograph. From this estimation results, relative error of estimation to the ovservation value was 6%, -which is mush smaller than 12% of the error of conventional method. 2.During the test period, daily distribution of long-term run-off discharge was estimated by the unit hydrograph model. From this estimation results, relative error of estimation by the application of standard unit hydrograph model was 12%. When estimating by each seasonal unit bydrograph model, the relative error was 14% during dry season 10% during semi-dry season and 7% during rainy season, which is much smaller than 37% of conventional method. Summing up the analysis results obtained above, it is convinced that qb-index method of this study for the estimation of effective rainfall be preciser than any other method developed before. Because even recently no method has been developed for the estimation of daily distribution of long-term run-off dicharge, therefore estimation value by unit hydrograph model was only compared with that due to kaziyama method which estimates monthly run-off discharge. However this method due to this study turns out to have high accuracy. If specially mentioned from the results of this study, there is no need to use each seasonal unit hydrograph model separately except the case of semi-dry season. The author hopes to analyze the latter case in future sudies.

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Study on Optimal Location of Washland Based on Economic Analysis (경제성 분석에 의한 강변저류지 최적위치 선정에 대한 연구)

  • Ahn, Tae-Jin;Byeon, Chen-Il;Roh, Hee-Sung;Baek, Chun-Woo
    • Journal of Korea Water Resources Association
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    • v.43 no.8
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    • pp.681-694
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    • 2010
  • In this study, methodology to determine optimal location of washlands based on economic analysis is presented. Install costs of washlands are calculated by construction cost and land compensatory cost and benefits of washlands are calculated from flood damage reduction and befit from using washland as wetland. Indirect approach for runoff-flood damage relationship is suggested and benefit-cost analysis is used for economic analysis. Economic analysis is added to existing models that used only flood reduction effect to determine optimal location of washlands. Suggested methodology is applied to 13 potential washlands in Anseong River basin to examine its applicability. Applied result of new methodology is compared with that of existing model. As the application results, it is possible to determine the optimal combinations of washlands can provide more economic benefit compared to existing studies. It is determined that considering economic analysis can be better option for decision making problem searching for optimal location of washlands.

Study on Water Stage Prediction Using Hybrid Model of Artificial Neural Network and Genetic Algorithm (인공신경망과 유전자알고리즘의 결합모형을 이용한 수위예측에 관한 연구)

  • Yeo, Woon-Ki;Seo, Young-Min;Lee, Seung-Yoon;Jee, Hong-Kee
    • Journal of Korea Water Resources Association
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    • v.43 no.8
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    • pp.721-731
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    • 2010
  • The rainfall-runoff relationship is very difficult to predict because it is complicate factor affected by many temporal and spatial parameters of the basin. In recent, models which is based on artificial intelligent such as neural network, genetic algorithm fuzzy etc., are frequently used to predict discharge while stochastic or deterministic or empirical models are used in the past. However, the discharge data which are generally used for prediction as training and validation set are often estimated from rating curve which has potential error in its estimation that makes a problem in reliability. Therefore, in this study, water stage is predicted from antecedent rainfall and water stage data for short term using three models of neural network which trained by error back propagation algorithm and optimized by genetic algorithm and training error back propagation after it is optimized by genetic algorithm respectively. As the result, the model optimized by Genetic Algorithm gives the best forecasting ability which is not much decreased as the forecasting time increase. Moreover, the models using stage data only as the input data give better results than the models using precipitation data with stage data.

Exploring Usability of Mobile Text Messaging Interfaces (휴대폰 문자메시지 기능의 인터페이스 이용성에 관한 연구)

  • Lee, Jee-Yeon
    • Journal of Information Management
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    • v.35 no.4
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    • pp.1-16
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    • 2004
  • In this paper, we outline the user interface problems that the text messaging users face to provide empirical basis for developing better improved mobile text messaging system. Our initial hypothesis was that the majority of the problems that the text messaging users face, namely, 1) difficulty in correctly understanding the intent of the incoming messages and 2) problem with frequently mis-addressing the recipient of the outgoing messages, can be accounted for by the poor usability of the text messaging user interface. Our analysis is based on the text message-based communication diaries, which were recorded for one week by each and every one of 75 college students, and survey taken from the same subjects. The data was collected in 2004. The students listed various difficulties including the limited message length, obscure input method, lack of mean to express emotional content, lack of receipt confirmation, lack of auto save feature when preparing messages to send, and lack of means to permanently save messages. Some of these problems were also identified in the previous studies. However, we were able to gather additional problems that the users face and also elicit potential solutions to remedy the problems. From these findings and analysis, we attempted to provide ways to improve the text messaging user interface.

Model Predictive Control for Distributed Storage Facilities and Sewer Network Systems via PSO (분산형 저류시설-하수관망 네트워크 시스템의 입자군집최적화 기반 모델 예측 제어)

  • Baek, Hyunwook;Ryu, Jaena;Kim, Tea-Hyoung;Oh, Jeill
    • Journal of the Korean Institute of Intelligent Systems
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    • v.22 no.6
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    • pp.722-728
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    • 2012
  • Urban sewer systems has a limitation of capacity of rainwater storage and problem of occurrence of untreated sewage, so adopting a storage facility for sewer flooding prevention and urban non-point pollution reduction has a big attention. The Korea Ministry of Environment has recently introduced a new concept of "multi-functional storage facility", which is crucial not only in preventive stormwater management but also in dealing with combined sewer overflow and sanitary sewer discharge, and also has been promoting its adoption. However, reserving a space for a single large-scale storage facility might be difficult especially in urban areas. Thus, decentralized construction of small- and midium-sized storage facilities and its operation have been introduced as an alternative way. In this paper, we propose a model predictive control scheme for an optimized operation of distributed storage facilities and sewer networks. To this aim, we first describe the mathematical model of each component of networks system which enables us to analyze its detailed dynamic behavior. Second, overflow locations and volumes will be predicted based on the developed network model with data on the external inflow occurred at specific locations of the network. MPC scheme based on the introduced particle swarm optimization technique then produces the optimized the gate setting for sewer network flow control, which minimizes sewer flooding and maximizes the potential storage capacity. Finally, the operational efficacy of the proposed control scheme is demonstrated by simulation study with virtual rainstorm event.

Violence and an Ethical Figure in Harold Pinter's One for the Road (해롤드 핀터의 『길 떠나기 전 한잔』에 나타난 폭력과 윤리적 주체)

  • Lee, Seon Hyeon
    • English & American cultural studies
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    • v.18 no.4
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    • pp.103-137
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    • 2018
  • Harold Pinter's One for the Road(1984) is a play about violence. Nicholas, who appears to be the manager of a place, interrogates Victor, Nicky, and Victor's wife Gila in a room for one day from morning to night. There is no direct physical violence in this play. But hints about the atrocities that took place outside the stage make the audience guess the violence and cruelty. Violence, which is not seen as such, is the central theme of the play. One for the road is worth reading as a resistance to breaking the mirror of global ideology, not as it deals with violent events confined to Turkey. The problem which Pinter had in mind, in particular, is that the United States plays a leading role in producing world-class ideologies, and that Britain is involved in collusion with the United States in cultivating such ideological fantasies, both abroad and at home. This thesis analyzes the contrasting reactions of each character in the play based on this social context. In particular, the conflicting reactions of the characters on the system are the most important conflict in the drama. Nicolas is a manager who moves on the system without seeing the truth. Victor and his family, on the other hand, do not move within the same ideology as Nicholas. This paper will take a look at what their strategies of resistance is and how they are revealed in the work. In fact, Nicholas appears split. Nicholas seemingly reacted decisively to the interpellation of the system. He expresses his belief and respect for the legitimacy of his actions. However, he has repeatedly sought the respect and love of Victor. Nicholas is now swaying. The theme that Nicholas presents consciously by grabbing at his own sway is 'Patriotism.' But this fantasy splits through Victor's silence and death demands. Therefore, the questions to be answered are: So why does Nicolas appear to be torn apart in a system that directs violence? But why is he forced to assimilate into the system? What other figures imply? To answer these questions, this thesis will take Slavoj Zizek's view of ideology. On the other hand, there are previous studies that read the system of violence in One for the road from the Althusser's perspective. Surely, this play explores the role of Ideological State Apparatus. However, from the point of view of Althusser, it is not possible to read Nicholas's division and the point of resistance seen by Victor's family. Pinter does not limit the scope of the ideological system as a closed one that regenerates ideologies, but secures the domain of main body resistance and struggle. On the other hand, there are already several domestic theses that read Pinter's work in Zizek's perspective. But these theses are mainly focused on analysis of Mountain Language. What this thesis would suggest is that there is a potential for an ethical figure of Zizek to be considered in One for the Road.

Obesity, Obstructive Sleep Apnea, and Metabolic Dysfunction (비만, 폐쇄성 수면무호흡증과 대사장애)

  • Kim, Jinkwan;Pyo, Sang Shin;Yoon, Dae Wui
    • Korean Journal of Clinical Laboratory Science
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    • v.53 no.4
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    • pp.285-295
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    • 2021
  • Sleep plays an important role in maintaining overall human health. There is increasing interest regarding the impact of sleep related disorders on metabolic diseases. Obstructive sleep apnea (OSA) is a common health problem, and in the last decade, the emergence of increasing obesity rates has further led to a remarkable increase in the prevalence of OSA, along with more prominent metabolic diseases. Obesity is the strongest risk factor for OSA. However, OSA is also known to cause obesity, suggesting an interaction between OSA and obesity. Although the underlying mechanisms leading to OSA-induced metabolic diseases are probably multi-factorial and are yet to be fully elucidated, the activation of inflammation and oxidative stress and the dysregulation of appetite-regulating hormones have emerged as important pathophysiological components of metabolic dysfunction and obesity observed in patients with OSA. Here, we will review the current state of research regarding the association of OSA with metabolic diseases and the possible pathophysiological mechanisms by which OSA could lead to such diseases. This will enhance our understanding of the potential interactions between OSA and obesity and between OSA and metabolic dysfunction.

The Effect of Government Support on Management Performance of ICT Venture Companies : Focusing on the Effectiveness of Funding and R&D Support (정부 지원이 ICT 벤처기업의 경영 성과에 미치는 영향 : 자금 및 연구개발 지원 효과를 중심으로)

  • Chung, Do-Bum;You, Hwasun
    • Journal of Technology Innovation
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    • v.29 no.3
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    • pp.63-90
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    • 2021
  • Today, venture companies are increasingly important in that they play a key role in national economic growth. However, ICT venture companies are having great difficulties in securing a sustainable competitive advantage due to rapid environmental changes, and as one of the ways to solve this problem, they rely on the government's support policy. Accordingly, this study analyzed the effect of government support on management performance of ICT venture companies. For empirical analysis, the data from the 2016 ICT venture panel survey was collected, and 687 and 538 companies were selected to analyze the effect of funding and R&D support, respectively. Then, through propensity score matching, companies that received government support and companies with similar characteristics (control group) were compared and analyzed. As a result of the analysis, it was found that funding support had a significant effect on the growth potential of ICT venture companies, and R&D support had a significant effect on the stability of ICT venture companies. This means that there is a difference in management performance of ICT venture companies depending on the type of government support. Through this study, it was possible to confirm the effect of government's policies, and various support policies for specific purposes should be pursued to foster ICT venture companies. In addition, for the continued growth of ICT venture companies in the future, it will be necessary to consider package (technology, management, commercialization, etc.) support rather than individual funding support or R&D support.

Development of a data analysis system for preventing school violence based on AI unsupervised learning (AI 비지도 학습 기반의 학교폭력 예방 데이터 분석 시스템 개발)

  • Jung, Soyeong;Ma, Youngji;Koo, Dukhoi
    • Journal of The Korean Association of Information Education
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    • v.25 no.5
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    • pp.741-750
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    • 2021
  • School violence has long been recognized as a social problem, and various efforts have been made to prevent it. In this study, we propose a system that can prevent school violence by analyzing data on the frequency of conversations between students, friendship and preference to be in the same group. This data was quantified using a Likert scale questionnaire, and also grouped into the appropriate number of clusters using the K-means algorithm. Additionally, the homeroom teacher observed the frequency and nature of conversations between students, and targeted specific individuals or groups for counseling and intervention, with the aim of reducing school violence. Data analysis revealed that the teachers' qualitative observations were consistent with the quantified data based on student questionnaires, and therefore applicable as quantitative data towards the identification and understanding of student relationships within the classroom. The study has potential limitations. The data used is subjective and based on peer evaluations which can be inconsistent as the students may use different criteria to evaluate one another. It is expected that this study will help homeroom teachers in their efforts to prevent school violence by understanding the relationships between students within the classroom.

Substantial Protective Immunity Conferred by a Combination of Brucella abortus Recombinant Proteins against Brucella abortus 544 Infection in BALB/c Mice

  • Arayan, Lauren Togonon;Huy, Tran Xuan Ngoc;Reyes, Alisha Wehdnesday Bernardo;Hop, Huynh Tan;Son, Vu Hai;Min, WonGi;Lee, Hu Jang;Kim, Suk
    • Journal of Microbiology and Biotechnology
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    • v.29 no.2
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    • pp.330-338
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    • 2019
  • Chronic infection with intracellular Brucella abortus (B. abortus) in livestock remains as a major problem worldwide. Thus, the search for an ideal vaccine is still ongoing. In this study, we evaluated the protective efficacy of a combination of B. abortus recombinant proteins; superoxide dismutase (rSodC), riboflavin synthase subunit beta (rRibH), nucleoside diphosphate kinase (rNdk), 50S ribosomal protein (rL7/L12) and malate dehydrogenase (rMDH), cloned and expressed into a pMal vector system and $DH5{\alpha}$, respectively, and further purified and applied intraperitoneally into BALB/c mice. After first immunization and two boosters, mice were infected intraperitoneally (IP) with $5{\times}10^4CFU$ of virulent B. abortus 544. Spleens were harvested and bacterial loads were evaluated at two weeks post-infection. Results revealed that this combination showed significant reduction in bacterial colonization in the spleen with a log protection unit of 1.31, which is comparable to the average protection conferred by the widely used live attenuated vaccine RB51. Cytokine analysis exhibited enhancement of cell-mediated immune response as IFN-${\gamma}$ is significantly elevated while IL-10, which is considered beneficial to the pathogen's survival, was reduced compared to control group. Furthermore, both titers of IgG1 and IgG2a were significantly elevated at three and four-week time points from first immunization. In summary, our in vivo data revealed that vaccination with a combination of five different proteins conferred a heightened host response to Brucella infection through cell-mediated immunity which is desirable in the control of intracellular pathogens. Thus, this combination might be considered for further improvement as a potential candidate vaccine against Brucella infection.