• Title/Summary/Keyword: point of impact

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A study on the Fatigue Factor as a Cause of Human Error (인간과실을 유발하는 피로요인 분석에 관한 연구)

  • Yang Won-Jae;Shin Chul-Ho;Keum Jong-So
    • Proceedings of KOSOMES biannual meeting
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    • 2004.11a
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    • pp.89-94
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    • 2004
  • For many years, fatigue was discounted as a potential cause of or contributor to human error. However, resent accident data and research point to fatigue as a cause of and/or contributor to human error precisely because of its impact on performance. The goal of this study is to analyze and examine of the fatigue factors related to human error. For this, we carried out the questionnaire survey which concerned with the fatigue factors.

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A Fast and Sensitive Method for the Simultaneous Determination and Quantification of Six Anionic Surfactants in Surface Water using HILIC-ESI-MS Technique

  • Dash, Upendra N.;Paul, Saroj Kumar
    • Mass Spectrometry Letters
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    • v.3 no.3
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    • pp.78-81
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    • 2012
  • The hydrophobic hydrocarbon chain and the polar sulfate group confer surfactant properties and enable them to be used as anionic surfactants. Anionic surfactants (AS) are known for their adverse impact on environment, particularly on aquatic ecosystem. In the present study a fast, sensitive and selective method for the determination and subsequent quantification of six anionic surfactants was developed using hydrophilic interactive liquid chromatography (HILIC) coupled to a electrospray ionization (ESI) mass spectrometer (MS), in the concentration range 15-20 ${\mu}g/L$. The capability of the method was established using regression analysis and ANOVA. The method performance was evaluated by analyzing real time surface water spiked with 1-dodecyl hydrogen sulfate at 15 ${\mu}g/L$. Combined efficiency of solid phase extraction and MS detection established recovery of 89% in presence of natural matrix. These results point out that HILIC coupled to multistage MS procedures can be a powerful technique for environmental applications concerning the screening of polar contaminants.

A Congestion Management Approach Using Probabilistic Power Flow Considering Direct Electricity Purchase

  • Wang, Xu;Jiang, Chuan-Wen
    • Journal of Electrical Engineering and Technology
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    • v.10 no.3
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    • pp.820-831
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    • 2015
  • In a deregulated electricity market, congestion of the transmission lines is a major problem the independent system operator (ISO) would face. Rescheduling of generators is one of the most practiced techniques to alleviate the congestion. However, not all generators in the system operate deterministically and independently, especially wind power generators (WTGs). Therefore, a novel optimal rescheduling model for congestion management that accounts for the uncertain and correlated power sources and loads is proposed. A probabilistic power flow (PPF) model based on 2m+1 point estimate method (PEM) is used to simulate the performance of uncertain and correlated input random variables. In addition, the impact of direct electricity purchase contracts on the congestion management has also been studied. This paper uses artificial bee colony (ABC) algorithm to solve the complex optimization problem. The proposed algorithm is tested on modified IEEE 30-bus system and IEEE 57-bus system to demonstrate the impacts of the uncertainties and correlations of the input random variables and the direct electricity purchase contracts on the congestion management. Both pool and nodal pricing model are also discussed.

Simulation of Nitrogen Movement in the Rainfall Event at an Upland Agricultural Watershed (임야지에서 강우사상시 질소거동 모의에 관한 연구)

  • Kim, Sang-Hyeon;Kim, Geon-Mok
    • Journal of Korea Water Resources Association
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    • v.34 no.5
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    • pp.521-532
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    • 2001
  • The propagation patterns of nitrogen during rainfall events are unsteady and heterogeneous due to the characteristics of generation and transport mechanisms. A simulation of non point source pollution was performed using GRASS-AGNPS to examine efficient management methods for diffusive pollution. Digital Elevation Model(DEM) was prepared to estimate the impact of topography on the transport pattern of diffusive pollutant Hanjaechon watershed on the Kyungbook province was selected as a study ares. Water quality samples were collected and analyzed for the calibration of the model. A heuristic approach was employed to improve the model performance. The model could successfully produce spatial distributions of nitrogen. The constructed map-layers may help to decision makers to determine the best management practices.

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Human Capital, Agglomeration Economies and Regional Economic Growth

  • Kim, Hong-Bae
    • Journal of the Korean Regional Science Association
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    • v.14 no.2
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    • pp.65-75
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    • 1998
  • Education is widely recognized one of main sources for growth. This paper attempts to incorporate the general recognition into formal regional growth model. The model structure is largely neoclassical. It produces a single good with the two factors, educated labor and non-educated labor, via a constant return production migrating to the region with the higher real wage. The educated labor in a region is accumulated by two sources, migration and physical education capital, while the non-educated labor is by only migration. The paper shows that regional growth equilibrium is characterized as a saddle point. This indicates the presence of the minimum threshold size that must be overcome before a region may grow. It contrasts sharply with results obtained in regional growth models. The paper suggests that regional growth is determined less by the technical characteristics of regional production function characteristics of regional production function but by the stock combination of educated function but by the stock combination of education labor and non-educated labor. Based on this result, the impact of agglomeration economies on regional growth is explored. It is by phase diagram demonstrated that the presence of agglomeration economies do not always lead a region to growth since there still exists the minimum threshold even in the presence of agglomeration economies.

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Determining widths of riparian ecosystem zone for water quality and ecosystem conservation - A case study for the Jinwee stream (수질개선과 생태서식환경을 고려한 수변생태구역 너비 결정 방법 - 진위천 적용을 중심으로 -)

  • SONG, Inhong;KIMm, IkJae
    • Journal of Korean Society of Rural Planning
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    • v.24 no.2
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    • pp.21-29
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    • 2018
  • Riparian management has become important as stream water quality as well as riparian ecosystem gain more public attentions. The objective of this study was to determine riparian widths based on the functions of nutrient removal and wildlife habitat protection and to apply for the Jinwee stream area as a preliminary case. Nitrogen and phosphorus filtration efficiencies were considered in water quality aspect, while the habitat radii of amphibian and reptiles were used for wildlife conservation purpose. In addition, observation of endangered species and human impact on wildlife disturbance in riparian area were also taken into account in determining riparian widths. The stream confluence zone was emphasized by doubling the riparian widths as the focal point for wildlife habitat conservation. As the results, three different levels of riparian widths were proposed depending on the major riparian functions and applied to the Jinwee stream section as the case study. The proposed method can be used to determine riparian width in other stream areas based on different functional focus, ie, water quality or riparian conservation purposes.

The Study of Health Promotion Behavior of Nursing College Student by the Self-Esteem (간호대학생의 자아존중감에 따른 건강증진행위에 미치는 요인)

  • Yoon, Hee-Sang
    • The Journal of Korean Society for School & Community Health Education
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    • v.11 no.2
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    • pp.115-127
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    • 2010
  • Objectives: This study was carried out to investigate the effects of improvement in health promotion behavior of nursing college students by the difference of self esteem. The students was divided two groups one is low level self esteem the other is high depending on median point of self esteem. The specific objectives were first, to find out the differences of health promotion behavior, self efficacy, health perception, fatigue level, depression, psychosocial wellbeing, second, to establish which factors determine their health promotion behavior between two groups. Methods: Self-administered questionnaires were given to 262 students enrolled in a nursing college. between may and June 2008. The questionnaire items included age, sex, education level, self esteem, self efficacy, health perception, fatigue, depression,, psychosocial well being and health promotion behavior. For statistical analysis, frequency, t-test, regression used for determining the factors effecting health promotion behavior. Results: The influencing factors were self efficacy among low level and self efficacy, fatigue and stress among high level. Self efficacy strong positive impact on health promotion behavior among both groups. Stress and fatigue was only effective among high level group. Conclusion: Based on the study results, improvement of health promotion behavior among nursing students requires the development and application of programs to manage self efficacy and stress as a precondition for depending on self esteem level.

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A Study on Change in Window Transmitted Solar and the Resultant Wall Surface Convective Heat Gain with Regard to Slat Reflectance of External and Internal Blinds (실내·외 블라인드의 Slat 반사율에 따라 창호 일사투과량 및 그에 따른 벽체 대류열획득량 분석)

  • Hyun, In-Tak;Lee, Jae-Ho;Yoon, Yeo-Beom;Lee, Kwang Ho
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.26 no.12
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    • pp.565-571
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    • 2014
  • Nowadays, to make buildings light weight and aesthetically pleasing, curtain wall structure are commonly used. Therefore, window to wall ratio is increasing, which has caused cooling and heating load in crease in buildings as well. This phenomenon has negative impact from energy point of view. This paper analyzes window and wall convective heat gain when the slat reflectance of external and internal blinds are changed for the better understanding of the fundamentals behind the phenomena. It was observed that, if slat reflectance is increased, window transmitted solar increases and convection heat rate is clearly affected. Among six surfaces including four walls, ceiling and floor, maximum convection heat rate occurs on the south wall in summer. On the other hand, ceiling and floor showed the lowest convection heat gain, since they are shared by adjacent floors.

The Impact of Japan's Pursuit of Constitutional Amendment on Marine Security and Countermeasures (일본의 개헌(改憲) 추진이 우리 해양안보에 미치는 영향과 대응방안)

  • Heo, Song
    • Strategy21
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    • s.44
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    • pp.54-78
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    • 2018
  • The core of the current constitutional amendment pursued by the Abe administration depends on the status of the Japanese Self-Defense Forces, which include the right to engage in war, in the legal and regular military positions. This is an important turning point for the Abe administration, which aims to become a normal country for Japan, and it is a series of steps that followed in the revision of the U.S. and Japan guidelines in 2015 and the overhaul of the security law in 2016. In this paper, we propose building "A navy Attractive to Alliances" as a way to secure Korea's maritime security under the current security environment. The term "attraction" refers to the alliance "first priority" especially in the United States. The way to do this is to transform the paradigm of the ROK-U.S. alliance into a naval hub in the vast seas, which will allow us to strengthen our national defense and even deter threats from neighboring countries. To this end, our navy needs to have a more active approach to U.S. East Asian strategy. If we can convince the United States to be a nation that contributes more to its East Asian strategy, it will only lead to a strengthening of the status of its alliance and expansion of its unilateral support and military capability against Japan, thus minimizing Japan's influence.

The Possible Change of the Electoral Authoritarianism in Malaysia: By Focusing on the 13th General Election (말레이시아 선거권위주의체제의 변화 가능성: 13대 총선을 중심으로)

  • HWANG, In-Won
    • The Southeast Asian review
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    • v.24 no.1
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    • pp.45-87
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    • 2014
  • This study traces the possibility of political change in the Malaysian electoral history, especially by focusing on the 13th general election held in May 2013. The results of the 13th general election was another turning point in the history of Malaysia's electoral politics. Following after the 12th general election held in 2008, opposition coalition(PR) achieves a remarkable electoral result by obtaining over 50% of the total votes. Opposition parties also successfully collapsed the ruling coalition(BN)'s two-third majority in parliamentary. It was de-facto defeat of the ruling coalition and victory of the opposition coalition. More precisely, the 2013 election results show that the reformasi movement, which was active in 1998-99 period, are still alive and its impact on Malaysian electoral politics get stronger. Malaysia has long been considered as a typical electoral authoritarian regime since its independence in 1957. It is because that there has been negative relations between electoral politics and political change through out its electoral history. As shown in the most recent two general elections held in 2008 and 2013, however, Malaysia's hegemonic political system can be possibly changed through electoral politics. This article examines the detailed results of the series of post-reformarsi general elections(1999, 2004, 2008, 2013) and its political implications towards the nexus of electoral politics and political change under the electoral authoritarian regime in Malaysia.