• Journal of environmental and Sanitary engineering
• /
• v.7 no.2
• /
• pp.37-52
• /
• 1992

Since the first sewage treatment plant was constructed in 1976, the sewerage systems of Korea have been rapidly expanded. As of the end of 1991, 22 sewage treatment plants with total capacity of 5.4 million tons/day are in operation which is equivalent of 3395 total daily sewage generation. Total extension of sewer 39.534 km in 1990 which is 55% of the target extension for the year 2001. However, the most sewage treatment plants employ activated sludge process which may not be suitable for medium and/or small scale plants. The poor existing sewer systems do not effectively collect and transport sewage to adversely affect the function of sewage treatment plant. To select the appropriate treatment system, the cities are classified into 3 categories such as large and medium size inland cities, small size cities and coastal cities. Considering the criteria suggested during this study, appropriate treatment processes were selected for each category. Conventional activated sludge process and step aeration process were found to be the most appropriate for big inland cities while biological nutrient removal processes should be considered for the cities discharge the effluent to lakes or reservoirs. RBC or Oxidation Ditch process might be appropriate for the medium size cities while several processes which do not require skilled operation and maintenance were suggested for the small cities. Ocean discharge after primary treatment can be considered for some east coast cities, Appropriate methodology to rehabilitate the existing sewers and strategy to convert combined sewer system to separate sewer system were proposed. This paper also include the appropriate management system for industrial wastewater, sludge and nightsoil.

• IE interfaces
• /
• v.21 no.3
• /
• pp.247-253
• /
• 2008

There are various types of unexpected troubles in service of a thermal power plant, which consists of many complicated high-tech mass equipments. The troubles are mostly caused by the manufacturing defects, the material deteriorations, the human errors, and others. Failures of its system due to the troubles, can bring on the extravagant economic loss and the qualitative degradation of electricity. Especially, it is most important to find a way to decrease human errors because it can result in not only the economic loss, but also morale declination of employees or the department related to the trouble. Therefore, we categorize previous troubles related to the human errors, and try to show the causations and the counter-measures based on the various categories such as maintenance, an operation, and system of the thermal power plants.

• Corrosion Science and Technology
• /
• v.3 no.4
• /
• pp.166-171
• /
• 2004

Recent developments in Bridge Management Systems (BMS) and in Life-Cycle Cost (LCC) of bridges, have raised the need for evaluation procedure of future condition (Deterioration) of a bridge. Predicting future deterioration is not an easy task due to limited past data to extrapolate from and also due to difficulty in measuring actual deterioration such as section loss of steel on an actual steel bridge. Also, increase in live load and reduction of resistance are random variables, thus a probabilistic approach should be adopted for determining the future deterioration. Due to difficulties in evaluation of future deterioration on steel bridges, accepting uncertainties within a reasonable error, a deterministic procedure using bridge condition rating can be a useful tool for projection of future condition of bridges to identify repair and maintenance needs. The object of this paper is to determine applicability of evaluating deterioration of steel bridge components based on Bridge condition ratings. Bridge condition ratings of bridge components show wide variation for bridges of same age and does not directly correlate well with the age of the bridge and/or deterioration of the bridge. High uncertainty can be reduced by breaking down the rating and by sensitivity analysis. From refined condition rating data, generalized deterioration profile of structures based on age can be derived. Examples are shown for sample bridges in USA. Approximately, 3,000 short to medium span steel bridges were listed in the inventory database. Results show wide variation of rating factors but by subdividing the Bridge condition ratings for various categories general deterioration profiles of steel bridges can be determined.

• KIEAE Journal
• /
• v.10 no.6
• /
• pp.55-66
• /
• 2010

The government is enacted "Housing Performance Grading Indication System" from qualitative housing supply policy and performance of housing under the background of looking for new plan to secure good housing stock and housing performance. This system consists of 5 main performance section, 14 performance categories and 20 detailed performance items. 5 main performance parts are sound insulation related grading(Light-weight impact sound insulation, heavy-weight floor impact sound insulation, noise emission in bathroom, airborne sound insulation for wall between units), Long-life housing related grading(flexibility, remodeling & maintenance, durability), environment related grading(landscape, indoor air quality and ventilation, energy performance), Living environment related grading(common resident facilities such as playground and consideration for the socially underprivileged such as the aged), Fire fire prevention grading(fire fire prevention). The purpose of this research is to analyze characteristics and assessment results of 20 detailed performance items on "Housing Performance Grading Indication System" which was enforced 240 cases from Jan 9th, 2006 to Sep 30th, 2010. The analysis of approval condition of detailed performance items will be important comments for understanding the current domestic level and development of technology.

• Journal of the Ergonomics Society of Korea
• /
• v.22 no.1
• /
• pp.81-94
• /
• 2003

The British railway safety research group has developed a risk assessment model for the railway infrastructure and major railway accidents. The major hazardous factors of the railway infrastructure were identified and classified in the model. The frequency rates of critical top events were predicted by the fault tree analysis method using failure data of the railway system components and ratings of railway maintenance experts, The consequences of critical top events were predicted by the event tree analysis method. They classified the Joss of accident due to railway system into personal. commercial and environmental damages. They also classified 110 hazardous event due to railway system into three categories. train accident. movement accident and non-movement accident. The risk assessment model of the British railway system has been designed to take full account of both the high frequency low consequence type events (events occurring routinely for which there is significant quantity of recorded data) and the low frequency high consequence events (events occurring rarely for which there is little recorded data). The results for each hazardous event were presented in terms of the frequency of occurrence (number of events/year) and the risk (number of equivalent fatalities per year).

• Journal of the Korean Society of Fashion and Beauty
• /
• v.3 no.2 s.2
• /
• pp.65-71
• /
• 2005

The aim of this research is to investigate the demographic characteristics of the purchase tendencies and shopping trends amongst female golfers and how these are influenced by their life style and to analyse their selection criteria for purchases of golf-related items. The research methodology was through the use of questionnaires, completed by female golfers in Gyeongnam. The results are as follows: life style trends of male golfers were analysed to be categorized into one of the following: the shopping-addicted, fashion-conscious, rationalist and family oriented spenders. The characteristics of these categories are described as one of the following: utilitarian-complacent, rationalist, self-worshipping, inconsiderate. The demographic characteristics showed notable variations only in age differences. The obtained results show that the influences of the variables are minimal and there was no notable correlation. Significant differences were observed from one life style group to another, in selection criteria for purchase, which mainly depended on style, design, colour, pattern, designer-label, co-ordinated looks, similarity, ease of maintenance and functionality. Comparisons were made between the previously categorized life-style-groups and notable differences were present in such characteristics as ostentatious, trendy, aesthetically pleasing and functional.

• Journal of Korean Public Health Nursing
• /
• v.35 no.3
• /
• pp.415-429
• /
• 2021

Purpose: The purpose of this study was to explore the health-related factors of the elderly in rural village in-depth and comprehensively based on the socio-ecological model. Methods: The data were collected from 22 elderly people through four focus group interviews and analyzed by deductive content analysis using four themes of the socio-ecological model (SEM) as an analysis matrix. Results: A total of 10 categories corresponding to the four themes of SEM were derived as follows: Intrapersonal level, "Awareness of Aging and Health", "Inefficient practice of health behavior", and "Daunted self-efficacy", Interpersonal level, "Social relations maintenance", and "Changing sense of community", Community level, "Local resources requiring improvement", "Problems caused by regional characteristics", "Disadvantaged group", and "Leadership and residents participation", Public policy level, "Health-related facilities and programs". Conclusion: We proposed the development and application of intervention programs that combined individual activities to improve self-management capacity and group activities to enhance social support and solidarity for rural villagers.

• Journal of Korean society of Dental Hygiene
• /
• v.22 no.5
• /
• pp.401-410
• /
• 2022

Objectives: This study aims to provide data that will improve the scope of national health insurance coverage by surveying the awareness of health insurance benefits, specifically for implants and dentures, among dental workers. Methods: Information was collected through questionnaires completed by 194 dental workers at dental hospitals and clinics. The multiple logistic regression analysis was conducted to confirm influential factors in recognizing the health insurance benefits application for dentures and implants. Results: Regarding the awareness about the validity of health insurance benefits, satisfaction with the appropriateness on the subjects of the denture application and implant application are appeared to be high with each 3.369 and 3.673. Regarding satisfaction with the appropriateness of free post-maintenance for implants, the awareness level regarding the validity of health insurance benefits was indicated as high at 3.673. Conclusions: The categories and levels of appropriate insurance benefits must be restructured continuously.

• Phonetics and Speech Sciences
• /
• v.16 no.1
• /
• pp.17-24
• /
• 2024

The Korean three-way stop contrast (lenis, aspirated, fortis) is currently undergoing a sound change, such that the primary cue distinguishing lenis and aspirated stops is shifting from voice onset time (VOT) to F0. Despite recent discussions of this shift, research on voice quality, traditionally considered an additional cue signaling the contrast, remains sparse. This study investigated the extent to which the associated voice quality [as reflected in the acoustic measurements of H1^*-H2^*, H1^*- A1^*, and cepstral peak prominence (CPP)] contributes to the three-way stop contrast, and how the realization is conditioned by prominence- vs. boundary-induced prosodic strengthening amid the ongoing sound change. Results for 12 native Korean speakers indicate that there was a substantial distinction in voice quality among the three stop categories with the breathiness of the vowel being the greatest after the lenis, intermediate after the aspirated, and least after the fortis stops, indicating the role of voice quality in the maintenance of the three-way stop contrast. Furthermore, prosodic strengthening has different effects on the contrast and contributes to the enhancement of the phonological contrast contingent on whether it is induced by prominence or boundary.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.25 no.5
• /
• pp.102-113
• /
• 2021

The deterioration environments caused by de-icing salt and airborne chlorides in the seashore, evaluated in the "Detailed guideline for safety and management practice of facilities (performance evaluation)", were reviewed in terms of penetrated chlorides into concrete on various road facilities. Target concrete structures, in this study, were 4 concrete barriers in Gangwon area, 3 concrete barriers and 1 retaining wall in Busan area, and 4 bridges in Gangwon-do, Seoul, Gyeonggi-do, and Busan. The deterioration environments were classified into three categories: direct and indirect de-icing salt attack, and airborne salt attack depending on the distance to seashore and the height of pier, and the penetrated chlorides in to concrete were analyzed. The results showed that (1) the regional deterioration environments were clearly classified by de-icing salt sprayed days (snowfall days), (2) the penetrated chlorides increased significantly when leakage occurred through slabs or expansion joints, and (3) the airborne chlorides affected to a height of 20 m concrete in the seashore, Busan. From these, it could be confirmed that the chloride ion penetration properties depend on the exposed aging environment, member location and height, and deterioration status, even on the same structure, so the selection of target members and location is very important in the inspection and maintenance. If the database of penetrated chlorides properties in various deterioration environments is constructed, it is expected that the proactive durability management on concrete structures will be possible in the field.