• Journal of Korean Society on Water Environment
• /
• v.22 no.3
• /
• pp.468-474
• /
• 2006

In the secondary settling tanks, three different types of settling phenomena occurs; i.e., zone settling for sludge thickening in the bottom part of settling tank, and discrete and flocculent settling for clarification in the upper part. In this paper, morphological parameters of the floc in sludge blanket layers along the length of a long rectangular tank were investigated. The plant used for this study had a serious bulking problem caused by Microthrix parvicella. Floc size decreased as the surface area of settling tank increases, which indicates that in the secondary settling tank where zone settling believed to be predominant, free or flocculent type of settling contributes to floc size distributions. Large floc particles deposit in the front zone of settling tank, but small and loose flocs mostly in the zone near its outlet. On the other hand, filament length contained in one gram of sludge blanket solid increases along the flow direction. Large flocs with less filaments settle faster, but small flocs having more filaments result in poor settling. These results support function of microorganism selection occurring in secondary settling tank. In addition, designing a long rectangluar settling tank with double hoppers might be one of the ways of bulking control, but this idea has to be verified with a further study.

• The Korean Journal of Health Service Management
• /
• v.13 no.3
• /
• pp.1-12
• /
• 2019

Objectives: The purpose of this study was to provide hospital management diagnosis status and basic data required for the future development of hospital management diagnosis program. Methods: We conducted a questionnaire survey on administrative staff of manager level or over of medical institutions in B metropolitan city. Results: As a result of analyzing the relative influence of the needs by hospital management diagnosis indicator, the effect of financial analysis indicator, patient treatment record indicator and medical revenues indicator were high in the medical institutions with number of beds of 100 beds or over and general hospital level or over both on a hospital level and on an individual level. Conclusions: Since the existing laws or systems are centered on large major hospitals, the management environment is very unfavorable for small and medium hospitals as can be seen from the results of this study. Therefore, the government should improve the transparency and rationality of the hospital management environment in Korea through regulation and system reforms that can be applied to all medical institutions.

• Journal of the Korean Society of Industry Convergence
• /
• v.26 no.5
• /
• pp.765-774
• /
• 2023

The Ministry of Employment and Labor implemented the process safety management(PSM) system from 1996 to prevent major industrial accidents caused by chemical substances, but the number of accidents did not drastically decrease. Even in workplaces with excellent PSM ratings, large-scale chemical accidents still occur due to non-compliance with safety work procedures and insufficient safety measures during maintenance and other work. Accordingly, the chemical accident risk warning system was introduced in 2014 to supplement the PSM system and prevent accidents that may occur during regular or unexpected maintenance and repair work. In the meantime, changes in the safety management system have been checked since the introduction of the chemical accident risk warning system at chemical handling workplaces, and based on the results, a plan for upgrading this system has been proposed. The effect of the CARW system was found to directly prevent accidents through wired and on-site consulting and post-management at the workplace and indirectly contribute to the establishment of a safety and health management system at the workplace, such as improving safety culture awareness.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.9 no.5
• /
• pp.53-68
• /
• 2014

This study is aimed at analyzing the factors that affect the behaviors of employee's investment, such as a decision making process in a variety of views and proving the extent of how those factors influence on their investment. The basic assumption is that the preceding factors that can be determined by the personal investment propensity, a psychological factor asserted by Behavior Financial Theory and financial-economic and social environment. This study uses Hershey's Investment Behavior Model(2007) as the main analysis tool to explain the investment behavior of individuals and deals with personal investment inclination in the psychological perspective of overconfidence, self-control and the risk tolerance propensity and add the financial and economic factors in terms of financial literacy and economic distress. Also the new preceding social environmental factors like social interaction and the effect of reference group are added to make this research to be more precise. This study analyze the adjustment effect of professional invest-consulting service that affect the fluctuation influence between the individual variables(those factors) and subordination variable(the level of investment satisfaction). The study reveals that overconfidence and self-control in direct ways have a positive effect on the level of investment satisfaction in terms of investment behavior and economic distress has a negative effect on the level of investment satisfaction. The adjustment effect provided by financial experts in investment consulting service is affirmed as the critical factor that increase the influence between self-control and the level of investment satisfaction. To conclude, the research reveals that the psychological factors are the main criteria when the workers as employees have to make investment decisions. To make investors be reasonable, a systematic financial education system provided by experts is needed from the early adolescent stages and financial companies should develop the relevant services of consulting service department as a key financial sector and financial investment products and consulting program and marketing tool pertinent to investors ages, vocational traits and their inclinations.

• Journal of the Korean Society for Library and Information Science
• /
• v.32 no.2
• /
• pp.121-142
• /
• 1998

Based on the comprehensive literature search and the sample library surveys, some observations are made on the impact of online information technologies for reference services. Various issues specifically with OPAC, CD-ROM, remote database access, and internet environment are overviewed as the source of and trigger for change in reference librarianship and in terms of expectations as well as difficulties. The paper then focuses on how these technologies influence on the roles of reference librarians as intermediaries in information providing, instructing, consulting, and evaluating functions. This leads to rethinking the conceptual basis of today's reference service and the competencies for reference librarians with new functions and responsibilities.

• IE interfaces
• /
• v.21 no.1
• /
• pp.109-119
• /
• 2008

Reliability of embedded softwares, as one of factors which affect system reliability, is the probability of failure-free software operation for a specified period of time in a specified environment. and Embedded software is different from general package software because hardware and operating system are tightly coupled to each other. Reliability evaluation models for embedded softwares currently used do not separate estimation and prediction models clearly, and even a standard model has not been proposed yet. In this respect, we choose a reliability estimation model suitable for embedded softwares among software evaluation models being used, and modified the model so as to accomodate recent software environments. In addtion, based on the model, the web-based reliability prediction tool RPX is developed. Finally, an embedded software is analyzed using the tool.

• 한국경영정보학회:학술대회논문집
• /
• 2008.06a
• /
• pp.52-63
• /
• 2008

Virtuality is a product of the information age, and as it plays a larger role in the activities of individuals, groups and organizations, the issue of how human behavior varies between virtual and physical space has become one of the most important questions facing the management environment of today. The purpose of this article is to examine how virtuality shapes individuals' social relationships within and outside their work groups. We developed a conceptual framework that explores the links between virtuality and social network based on computer-mediated communication theory and social network theory. Using data from 172 individuals of 42 project teams in 5 global business consulting firms, we tested cross-level hypotheses. The results of hierarchical linear modeling (HLM) indicate that virtuality significantly influences individual's internal tie strength as well as external bridging ties. The results also show the effects of virtual process via CMC vary along with the virtual context.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.48 no.1
• /
• pp.19-26
• /
• 2016

In the consumer products industry, it has been highly desirable to develop objective test methods to replace subjective evaluation methods. In developing an objective test method, subjective evaluation data should be on a linear scale. According to Thurstone's theory of comparative judgment, a%-preference from a paired-comparison test can be converted to a linear-scale value. The required number (N) of paired-comparison tests increases dramatically as the number of products increases. This problem should be solved by classifying the total products into several subgroups consisting of 3-4 products in each group. By doing so, it can not only significantly reduce the number of required paired-comparison tests, but it can also obtain more reliable, reproducible data.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2005.05b
• /
• pp.52-59
• /
• 2005

The goal of this project is to estimate the instream flow of the Han River Basin to ensure the adequate supply of suitable quality water for preservation and enhancement of aquatic ecosystems. A applied model is Physical Habitant Simulation System(PHABSIM) of Instream Flow Incremental Methodology(IFIM). The parameters which are needed to simulation by PHABSIM such as flow depth, velocity distribution and channel cover with cross section data are obtained by field survey. The Habitat Suitability Criteria with the application of univariate curve on Zacco platypus as a target species was able to be established by conducting the field investigation. The estimated results of ecological recommended instream flow by this study has important meanings that the future river management have to seriously take into account for the natural environment and functions of river system.

• ETRI Journal
• /
• v.32 no.5
• /
• pp.687-694
• /
• 2010

Breaks in presence (BIP) are those moments during virtual environment (VE) exposure in which participants become aware of their real world setting and their sense of presence in the VE becomes disrupted. In this study, we investigate participants' experience when they encounter technical anomalies during game play. We induced four technical anomalies and compared the BIP responses of a navigation mode game to that of a combat mode game. In our analysis, we applied a linear mixed model (LMM) and compared the results with those of a conventional regression model. Results indicate that participants felt varied levels of impact and recovery when experiencing the various technical anomalies. The impact of BIPs was clearly affected by the game mode, whereas recovery appears to be independent of game mode. The results obtained using the LMM did not differ significantly from those obtained using the general regression model; however, it was shown that treatment effects could be improved by consideration of random effects in the regression model.