• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.1C
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• pp.19-29
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• 2008

As a part of study to develop LRFD (Load and Resistance Factor Design) codes for foundation structures in Korea, reliability analyses for driven steel pipe piles are performed and the target reliability indices are selected carefully. The 58 data sets of static load tests and soil property tests conducted in the whole domestic area were collected and analyzed to determine the representative bearing capacities of the piles. The static bearing capacity formula and the Meyerhof method using N values are applied to calculate the expected design bearing capacity of the piles. The resistance bias factors were evaluated for the two static design methods by comparing the representative bearing capacities with the design values. Reliability analysis was performed by two types of advanced methods: First Order Reliability Method (FORM), and Monte Carlo Simulation (MCS) method using resistance bias factor statistics. The static bearing capacity formula exhibited relatively small variation, whereas the Meyerhof method showed relatively high inherent conservatism in the resistance bias factors. Reliability indices for safety factors in the range of 3 to 5 were evaluated respectively as 1.50~2.89 and 1.61~2.72 for both of the static bearing capacity formula and the Meyerhof method. The target reliability indices are selected as 2.0 and 2.33 for group pile case and 2.5 for single pile case, based on the reliability level of the current design practice and considering redundancy of pile group, acceptable risk level, construction quality control, and significance of individual structure.

• Journal of Korean Tunnelling and Underground Space Association
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• v.11 no.1
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• pp.71-83
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• 2009

Shotcrete is an important primary support for tunnelling in rock. The quality control of shotcrete is a core issue in the safe construction and maintenance of tunnels. Although shotcrete may be applied well initially onto excavated rock surfaces, it is affected by blasting, rock deformation and shrinkage and can debond from the excavated surface, causing problems such as corrosion, buckling, fracturing and the creation of internal voids. This study suggests an effective non-destructive evaluation method of the tunnel shotcrete bonding state applied onto hard rocks using the impact-echo (IE) method and ground penetration radar (GPR). To verify previous numerical simulation results, experimental study carried out. Generally, the bonding state of shotcrete can be classified into void, debonded, and fully bonded. In the laboratory, three different bonding conditions were modeled. The signals obtained from the experimental IE tests were analyzed at the time domain, frequency domain, and time-frequency domain (i.e., the Short- Time Fourier transform). For all cases in the analyses, the experimental test results were in good agreement with the previous numerical simulation results, verifying this approach. Both the numerical and experimental results suggest that the bonding state of shotcrete can be evaluated through changes in the resonance frequency and geometric damping ratio in a frequency domain analysis, and through changes in the contour shape and correlation coefficient in a time-frequency analysis: as the bonding state worsens in hard rock condition, the autospectral density increases, the geometric damping ratio decreases, and the contour shape in the time-frequency domain has a long tail parallel to the time axis. The correlation coefficient can be effectively applied for a quantitative evaluation of bonding state of tunnel shotcrete. Finally, the bonding state of shotcrete can be successfully evaluated based on the process suggested in this study.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.4
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• pp.36-50
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• 2012

This study was carried out to find contradiction factors on laws for children's activity spaces and facilities and to suggest the rational options to control and manage those spaces and facilities by environmental and landscape planning methods. The results of this study are as follows: 1. The major laws related to the environmental safety for children's activity spaces are "Environmental Health Act (ERA)" for managing the environmental safety of children's activity spaces; "Safety Supervision Law of Children's Play Facilities(SSLCPF)" for the inspection and management for safety of children's play facilities; "Quality Management and Industrial Products Safety Management Law(QMIPSML)" for managing safety certification on children's play equipments. 2. The interior space such as "living room" by the Children's Welfare Law(CWL), "Children Park" by the Act on Urban Parks and Green Spaces(AUPGS), "classroom" on private educational institutes by the Act on Establishment and Operation Private Lesson and Training(AEOPLT) and "nursing room" of child care center smaller than $430m^2$ are needed to be managed as an activity space. 3. In order to reduce industrial burden in the production, establishment, construction, and operation and to minimize unwilling extra burden in the administration effort due to legally double regulate, it is necessary to mitigate the inspections on the equipment certificate from QMIPSML and overlapped or different factors and standards must be unified. With this study, the landscape domain could he enlarged from producing, import of play equipment and establishment, construction and operation of play facilities for a comprehensive range of activity spaces, and the landscape industry such as engineering industry, academic research, management, etc.

• Journal of Korean Academy of Nursing
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• v.30 no.1
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• pp.122-136
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• 2000

Chronic illness requiring attention and management during a long period of time puts great burden onto patients, their family and society. For patients with chronic illnesses, providing social support is the most important, and the fundamental support comes from their spouses. Amount and quality of support from spouses seems to differentiated according to the sex of patients. Female patients tend to believe that their spouses are not very supportive. Therefore, the researchers assessed the burden of husbands of female arthritis patients to discover the factors that result in greater burden. Also, they developed a theoretical model of husbands′ care for their wives through a qualitative research into husbands′ experience. Method 1: The study material was 650 female arthritis patients registered in an arthritis clinic. The questionnaire about the disease experience of female arthritis patients and the burden of husbands were sent. Returned questionnaires numbered 210(32.3%) and 27 were excluded because of inadequate answers. The remaining 183 questionnaires were analyzed. The mean age of the patients was 51 years and the mean age of spouses was 55 years. The mean marital period was 28 years. The average duration since diagnosis was 9.1 years. Education level was varied from primary school to graduate school, and average income/month was 1,517,300 won. Method 2: Initial questionnaire studies on the burden of husbands were performed. Among 183 responding husbands, 23 consented to participate for a qualitative research. Data was obtained by direct and telephone interviews. The mean age of participants was 58 years, and the educational level and socioeconomic status also varied. Result: 1. Husbands′ burden: The average burden was 57.68 with a range of 6-96. 2. Burden and general characteristics: The husband′s burden correlated with the age of the patients, numbers in the family, therapy methods, patient′s level of discomfort, patient′s disease severity, patient′s level of dependence and the husband′s understanding of the level of severity. 3. Linear correlation analysis on burden: The husbands′ burden is explained in 22.5% by husband′s recognition of level of severity and husbands′ age. 4. There were four patterns of the burden on husbands: both objectve burden and subjective burden were high(pattern I), both of objectve burden and subjective burden were low(pattern II), objective burden was high but subjective burden was low(pattern III), objective burden was low but subjective burden was high(pattern IV). The pattern was correlated with the family income, educational level of the patients and their husbands, therapy methods, patient′s level of discomfort, patient′s disease severity, patient′s level of dependence and husband′s understanding of level of severity. 5. The core category of the caring experience of the husbands with arthritis patients was "companionship". The causal factor was the patients′ experience due to symptoms : physical disfigurement, pain, immobility, limitation of house chores, and limitation of social activities. Contextural factors are husbands′ identification of housework and husbands′ concern about the disease. The mediating factors are economic problems, fear of aging, feeling of limitation and family support. The strategy for interaction is mind control and how to solve emotional stress. The "companionship" resulted from caring activities, participation of household activities, helping patients′ to coping with emotional experience. 6. Companionship is established through the process of entering intervention, and caring state of mind. Entering intervention is the phase of participation of therapy and involvement of houseworks. The caring phase consists of decision on therapy, providing therapy, providing direct care, and taking over the household role of wife. Through caring phase, the changing phase set a stage in which husbands consolidate the relationship with their wives, and are reminded of the meaning of marriage. As a result, in changing phase, husbands′ companionship is enhanced. In conclusion, nursing care of chronic illnesses should include a family member especially the spouse. All information on disease shoud be provided to patients and whole family member. Strong support should also be provided to overcome difficulties in taking over role of other sex. Then the quality of life of patients and families will be much improved.

• Journal of Wetlands Research
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• v.23 no.4
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• pp.327-341
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• 2021

The riparian eco-belt is an efficient technique that can reduce non-point pollution sources in the basin and improve ecological connectivity and health. In Korea, a legal system for the construction and management of riparian eco-belts is in operation. However, it is currently excluded that rivers and floodplains in dam reservoir that are advantageous for buffer functions such as control of non-point pollutants and ecological habitats. Accordingly, this study presented and analyzed a plan to select a site for an integrated riparian ecol-belt that comprehensively evaluates the water quality and ecosystem characteristics of each dam floodplain and riparian zone for the Daecheong Dam basin in Geum River watershed. First, the Daecheong Dam basin was divided into 138 sub-basin with GIS, and the riparian zone adjacent to the dam floodplain was analyzed. Sixteen evaluation factors related to the ecosystem and water quality impact that affect the selection of integrated riparian eco-belt were decided, and weights for the importance of each factor were set through AHP analysis. The priority of site suitability was derived by conducting an integrated evaluation by applying weights to sub-basin by floodplains and riparian zone factors. In order to determine whether the sites derived through GIS site analysis are sutiable for actual implementation, five sites were inspected according to three factors: land use, pollution sources, and ecological connectivity. As a result, it was confirmed that all sites were appropriate to apply integrated riparian ecol-belt. It is judged that the riparian eco-belt site analysis technique proposed through this study can be applied as a useful tool when establishing an integrated riparian zone management policy in the future. However, it might be necessary to experiment various evaluation factors and weights for each item according to the characteristics and issues of each dam. Additional research need to be conducted on elaborated conservation and restoration strategies considering the Green-Blue Network aspect, evaluation of ecosystem services, and interconnection between related laws and policy and its improvements.

• Journal of the Korean Geosynthetics Society
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• v.12 no.4
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• pp.67-76
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• 2013

Landfill require special care due to the dangers of nearby surface water and underground water pollution caused by leakage of leachate. The leachate does not leak due to the installation of the geomembrane but sharp wastes or landfill equipment can damage the geomembrane and therefore a means of protecting the geomembrane is required. In Korea, in accordance with the waste control act being modified in 1999, protecting the geosynthetics liner on top of the slope of landfill and installing a drainage layer to fluently drain leachate became mandatory, and technologies are being researched to both protect the geomembrane and quickly drain leachate simultaneously. Therefore, this research has its purpose in studying the drainage functions of leachate and protection functions of the geomembrane in order to examine the application possibilities of Geo-Multicell-Composite (GMC) as a Leachate Collection Removal and Protection System (LCRPs) at the slope on top of the geomembrane of landfill by observing methods of inserting filler with high-quality water permeability at the drainage net. GMC's horizontal permeability coefficient is $8.0{\times}10^{-4}m^2/s$ to legal standards satisfeid. Also crash gravel used as filler respected by vertical permeability is 5.0 cm/s, embroidering puncture strength 140.2 kgf. A result of storm drain using artificial rain in GMC model facility, maxinum flow rate of 1,120 L/hr even spray without surface runoff was about 92~97% penetration. Further study, instead of crash gravel used as a filler, such as using recycled aggregate utilization increases and the resulting construction cost is expected to savings.

• Korean Journal of Ecology and Environment
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• v.40 no.1
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• pp.130-142
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• 2007

This study was to examine impacts of turbid water on fish community in the downstream of Yongdam Dam during the period from June to October 2006. For the research, we selected six sampling sites in the field: two sites were controls with no influences of turbid water from the dam and other remaining four sites were the stations for an assessment of potential turbid effects. We evaluated integrative health conditions throughout applications of various models such as necropsy-based fish health assessment model (FHA), Index of Biological Integrity (IBI) using fish assemblages, and Qualitative Habitat Evaluation Index (QHEI). Laboratory tests on fish exposure under 400 NTU were performed to find out impact of turbid water using scanning electron microscope (SEM). Results showed that fine solid particles were clogging in the gill in the treatments, while particles were not found in the control. This results indicate that when inorganic turbidity increases abruptedly, fish may have a mechanical abrasion or respiratory blocking. The stream health condition, based on the IBI values, ranged between 38 and 48 (average: 42), indicating a "excellent" or "good" condition after the criteria of US EPA (1993). In the mean time, physical habitat condition, based on the QHEI, ranged 97 to 187 (average 154), indicating a "suboptimal condition". These biological outcomes were compared with chemical dataset: IBI values were more correlated (r=0.526, p<0.05, n=18) with QHEI rather than chemical water quality, based on turbidity (r=0.260, p>0.05, n=18). Analysis of the FHA showed that the individual health indicated "excellent condition", while QHEI showed no habitat disturbances (especially bottom substrate and embeddeness), food-web, and spawning place. Consequently, we concluded that the ecological health in downstream of Yongdam Dam was not impacted by the turbid water.

• The Journal of Korean Society for Radiation Therapy
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• v.18 no.2
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• pp.81-87
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• 2006

Purpose: Few researches have been peformed on the dose distribution of the moving organ for radiotherapy so far. In order to simulate the organ motion caused by respiratory function, multipurpose phantom and moving device was used and dosimetric measurements for dose distribution of the moving organs were conducted in this study. The purpose of our study was to evaluate how dose distributions are changed due to respiratory motion. Materials and Methods: A multipurpose phantom and a moving device were developed for the measurement of the dose distribution of the moving organ due to respiratory function. Acryl chosen design of the phantom was considered the most obvious choice for phantom material. For construction of the phantom, we used acryl and cork with density of $1.14g/cm^3,\;0.32g/cm^3$ respectively. Acryl and cork slab in the phantom were used to simulate the normal organ and lung respectively. The moving phantom system was composed of moving device, moving control system, and acryl and cork phantom. Gafchromic film and EDR2 film were used to measure dose ditrbutions. The moving device system may be driven by two directional step motors and able to perform 2 dimensional movements (x, z axis), but only 1 dimensional movement(z axis) was used for this study. Results: Larger penumbra was shown in the cork phantom than in the acryl phantom. The dose profile and isodose curve of Gafchromic EBT film were not uniform since the film has small optical density responding to the dose. As the organ motion was increased, the blurrings in penumbra, flatness, and symmetry were increased. Most of measurements of dose distrbutions, Gafchromic EBT film has poor flatness and symmetry than EDR2 film, but both penumbra distributions were more or less comparable. Conclusion: The Gafchromic EBT film is more useful as it does not need development and more radiation dose could be exposed than EDR2 film without losing film characteristics. But as response of the optical density of Gafchromic EBT film to dose is low, beam profiles have more fluctuation at Gafchromic EBT. If the multipurpose phantom and moving device are used for treatment Q.A, and its corrections are made, treatment quality should be improved for the moving organs.

• Journal of Intelligence and Information Systems
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• v.17 no.2
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• pp.61-75
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• 2011

A Geographic Information System(GIS) is a system that captures, stores, analyzes, manages and presents data with reference to geographic location data. In the later 1990s and earlier 2000s it was limitedly used in government sectors such as public utility management, urban planning, landscape architecture, and environmental contamination control. However, a growing number of open-source packages running on a range of operating systems enabled many private enterprises to explore the concept of viewing GIS-based sales and customer data over their own computer monitors. K telecommunication company has dominated the Korean telecommunication market by providing diverse services, such as high-speed internet, PSTN(Public Switched Telephone Network), VOLP (Voice Over Internet Protocol), and IPTV(Internet Protocol Television). Even though the telecommunication market in Korea is huge, the competition between major services providers is growing more fierce than ever before. Service providers struggled to acquire as many new customers as possible, attempted to cross sell more products to their regular customers, and made more efforts on retaining the best customers by offering unprecedented benefits. Most service providers including K telecommunication company tried to adopt the concept of customer relationship management(CRM), and analyze customer's demographic and transactional data statistically in order to understand their customer's behavior. However, managing customer information has still remained at the basic level, and the quality and the quantity of customer data were not enough not only to understand the customers but also to design a strategy for marketing and sales. For example, the currently used 3,074 legal regional divisions, which are originally defined by the government, were too broad to calculate sub-regional customer's service subscription and cancellation ratio. Additional external data such as house size, house price, and household demographics are also needed to measure sales potential. Furthermore, making tables and reports were time consuming and they were insufficient to make a clear judgment about the market situation. In 2009, this company needed a dramatic shift in the way marketing and sales activities, and finally developed a dedicated GIS_based market analysis and sales management system. This system made huge improvement in the efficiency with which the company was able to manage and organize all customer and sales related information, and access to those information easily and visually. After the GIS information system was developed, and applied to marketing and sales activities at the corporate level, the company was reported to increase sales and market share substantially. This was due to the fact that by analyzing past market and sales initiatives, creating sales potential, and targeting key markets, the system could make suggestions and enable the company to focus its resources on the demographics most likely to respond to the promotion. This paper reviews subjective and unclear marketing and sales activities that K telecommunication company operated, and introduces the whole process of developing the GIS information system. The process consists of the following 5 modules : (1) Customer profile cleansing and standardization, (2) Internal/External DB enrichment, (3) Segmentation of 3,074 legal regions into 46,590 sub_regions called blocks, (4) GIS data mart design, and (5) GIS system construction. The objective of this case study is to emphasize the need of GIS system and how it works in the private enterprises by reviewing the development process of the K company's market analysis and sales management system. We hope that this paper suggest valuable guideline to companies that consider introducing or constructing a GIS information system.

• Journal of Korea Spatial Information System Society
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• v.2 no.2 s.4
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• pp.5-23
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• 2000

Since 1995, national and local governments have competitively initiated many and large GIS projects and audit for the projects becomes an important issue. So far, the audit in the Information Technology(IT) area has tried to deal with the issue but ineffectiveness has been found for the successful GIS project management. Effective auditing is a critical element for the project management. In order to establish a proper audit model for the GIS projects and to promote auditing activities in the projects, this study constructs two hypotheses and tries to prove them. The hypotheses are as follows : 1) For a good audits model for GIS, unique characteristics of a GIS project audit items and the scope of the audit need to be identified. 2) The scope of audit needs to be classified according to the requests from tasks in the projects. To prove the hypotheses, this study analyzes positive aspects of audit in IT and construction projects, clarifies the audit items in GIS projects by comparing with them, and classifies the scope of the GIS audit based on various types of GIS projects. As a results, 5 types of the GIS audit are identified : (1) audit for project management, (2) audit focused on IT, (3) audit characterized by GIS technologies, (4) GIS database audit and (5) consulting services for critical problems in the projects. In addition, 4 criteria in classifying the GIS projects are suggested for the GIS audit. The 4 criteria are domain, scope, duration, and GIS applications technologies. Especially, GIS technology considered in this study includes GIS software, methodologies for GIS development, GIS database and quality control of GIS data, which are not usually reflected in the existing studies about in GIS audit. Because the GIS audit depends on a type of GIS projects, scopes of the audit can be flexibly reconstructed in accordance with the types of GIS projects. This is a key to effective and realistic audit for the future GIS projects. Strategies for effective GIS audit are also proposed in terms of the following: GIS project management, goal establishment in each audit stage, documentation from GIS audit, timing strategies for intensive GIS audit, and designing team structure.