• Geophysics and Geophysical Exploration
• /
• v.14 no.4
• /
• pp.267-273
• /
• 2011

A cluster of micro-earthquakes in the transition zone between the continental and oceanic crust in the East Sea was relocated using the Joint Hypocenter Determination (JHD) method. In order to increase the number of available earthquakes and to take advantage of the high detection capability of the Korea National Seismic Network (KNSN), continuously recorded seismic data were reviewed to identify 56 micro-earthquakes occurring in a 20 km ${\times}$ 20 km region. The initial earthquake hypocenters were determined using a routine single event location method. Single event locations do not reveal any significant structures in the study area. After relocating the earthquake hypocenters using the JHD technique, the earthquakes were clustered and four potential faults responsible for earthquake generation in the subsurface were delineated. They are defined by two sub-vertical and two steeply south-dipping seismicities located next to each other.

• Geotechnical Engineering
• /
• v.14 no.4
• /
• pp.17-32
• /
• 1998

has been much progress in theories and construction techniques to secure the stability of the underground structures. Recently, several studios have shown that it is possible to predict the existence of discontinuities ahead of a tunnel face by analyzing 3-dimensional absolute displacements measured during tunnel excavation. This paper concentrated on the development of a methodology to predict the existence and location of the discontinuities, or the void space(abandoned mine) , by performing 3-dimensional FEM analysis and considering the stress relocation caused by arching effect during excavation. Also, this study tried to verify deformation for choosing the most suitable support system. The results of this study might provide a way of safer and economical tunnel construction by utilizing the in-situ monitoring data.

• Journal of the Korean Regional Science Association
• /
• v.31 no.2
• /
• pp.47-61
• /
• 2015

The purpose of this study to empirical analysis of the effects of distance-decay for the relocated firms in the Seoul Metropolitan Area(SMA). In addition, this study was constructed distance-decay function for the relocated firms by industrial types using a general distance-decay function. The data of relocated firms in the SMA extracted from the spatial database which was constructed in an previous research. The industrial type divided into 3 parts which are construction, manufacturing, and service. The result of empirical analysis by each industrial type of the effect of distance-decay, the explanatory power($R^2$) of the each function were all high. In the construction, the adjusted $R^2$ of the distance-decay function was 0.728, the manufacturing was 0.802 and the service was 0.812. It means the effect of distance decay for the relocated firms in construction industrial type more big than the effects of distance decay for the manufacturing and service industrial types.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.15 no.9 s.102
• /
• pp.1009-1015
• /
• 2005

Fluid-elastic instability and turbulence excitation for an under developing steam generator are investigated numerically. The stability ratio and the amplitude of turbulence excitation are obtained by using the $PIAT^{(R)}$ (program for integrity assessment of steam generator tube) code from the information on the thermal-hydraulic data of the steam generator. The aspect ratio, the ratio between the height of U-tube from the upper most tube support Plate (h) and the width of two vertical portion of U-tube (w), is defined for geometric parameter study. Several aspect ratios with relocation of tube support plates are adopted to study the effects on the mode shapes and characteristics of flow-induced vibration. When the aspect ratio exceeds value of 1, most of the mode shapes at low frequency are generated at the top of U-tube. It makes very high value of the stability ratio and the amplitude of turbulent excitation as well. We can consider that the local mode shape at the upper side of U-tube will develop the wear phenomena between the tube and the anti-nitration bars such as vortical, horizontal, and diagonal strips. It turns out that the aspect ratio reveals very important parameter for the design stage of the steam generator. The appropriate value of the aspect ratio should be specified and applied.

• The KIPS Transactions:PartA
• /
• v.10A no.2
• /
• pp.149-156
• /
• 2003

In the latest medical world, the attempt of reconstructing anatomical human body system using computer graphics technology awakes people's interests. Actually, this trial has been made in dentistry too. There are a lot of practicable technology fields using computer graphics in dentistry For example, 3D visualization and measurement of dental data, detection of implant location, surface reconstruction for restoring artificial teeth in prostheses and relocation of teeth in orthodontics can be applied. In this paper, we propose methods for definitely detecting the geometric features of teeth such as cusp, ridge, fissure and pit, which have been used as most important characteristics in dental applications. The proposed methods are based on the approximate curvatures that are measured on a 3D tooth model made by scanning an impression. We also give examples of the geometric features detected by using the proposed methods. Comparing to other traditional methods visually, the methods are very useful in detecting more accurate geometric features.

• Journal of Korean Academy of Nursing
• /
• v.21 no.3
• /
• pp.383-395
• /
• 1991

This study was to investigated the factors influencing the decisions of nurses to resign. The purpose was to contribute information useful for the effective management of nurse staffing resources. The specific objectives were as follows : 1. To investigate the level of job satisfaction of nurses who resign. 2. To analyze the relationship of job expectations and the decisions to resign. 3. To investigate the major reason for nurses' resignations. 4. To identify the relationship of the general characteristics of the nurses and the factors influencing their decisions to resign. 5. To analyze the relationship of the intention to resign and the factors influencing the decisions to resign. The sample consisted of 90 nurses who worked at Y hospital in Seoul from march. 1987 to Feb. 1988 and who had resigned. The instruments used for this study were slavitt et al's Index of Work Satisfaction Scale and a job expectations scale developed by the researcher Analysis of data was done using frequency, t-test and ANOVA. The results of study were as follows : 1. There was no difference in the job satisfaction level of nurses who resigned compared with nurses in active service but the subcategory interaction score was lower and the subcategory salary score was higher than for nurses in active service. 2. Low job expectation scores influenced the decision to resign. 3. The major reason for resigning were personal problems such as marriage, childbirth, and relocation of family. 4. The length of employment and the number of different service areas of the nurses who resigned were associated with the job satisfaction level. 5. The nurses who had have an intention to resign while in active service had lower scores for job satisfaction and the job expectation score was a greater influence on the decision to resign. In conclusion, the factors influencing the decisions of nurse to resign were job satisfaction, job expectations and intention to resign while still in active service.

• Journal of Korea Port Economic Association
• /
• v.28 no.3
• /
• pp.215-234
• /
• 2012

Since ports play a role of gateway to the sea and hinterlands, it is essential to analyse the networks of shipping and inland when evaluating the function and development of a port. The container port of Gwangyang, starting to operate its facilities in 1998, has developed itself as a hub port. Using the data of shipping schedules of Korean ports and the measurement of centrality in sociology, this study analyses the process of world-wide shipping network expansion in Gwangyang and concludes some implications including earlier development of shipping networks due to incentives to shipping companies. Although Gwangyang port also has been expanding its inland network through developing trucking, railway transport, and coastal shipping, it has weakness in inland network as in the cases of interruption in 2004, resumption in 2009 and re-interruption in 2012 at coastal shipping. In 2000s the expansion of shipping and inland networks at the newly built container ports such as Pyungtaek, Ulsan, and Gunsan has enticed the competition among Korean ports at each hinterland. Nevertheless, the operation of Gwangyang container port is considered to affect indirectly the relocation of some manufacturers including Samsung Electronics. Studies on interrelation between development of container port and geographical demography of manufacturers are needed to assess the effects of container port on regional economy.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.23 no.2
• /
• pp.307-313
• /
• 1999

This study investigated material the type(sewn-in stamped-on etc) of the label and its placement(location on the product) on children's clothing in order to survey consumer complaints to suggest the improvement. The data were collected from label-producing companies by surveying children's clothing displayed at department store as well as by questionnaire to 205 consumers who were mothers of preschool children. The results were as follows : 1. 100% polyester was the most used raw material for brand labels and nylon was for care labels. 2. Most brand labels were one piece labels and located inside the back of neck line by sewn-in either on the top on each sides or on all four sides, Care labels were usually sewn-in on the inside of left-side seam line. The texture of care label was softer than that of brand label and two pieces of care labels were widely used, 3. 67.3% of consumers complained of its stiffness while 36.1% of consumers complained of rough surface and edge 85.4% of consumers complained of an itch caused by brand labels and claimed to detach labels. For care labels 36.6% expressed displeasure of stiffness of labels while 39% complained of annoyance due to too many pieces of labels. 4. Major suggestions from the consumers were change of raw materials and relocation of brand labels. For the care labels changes of material form and type of labels were suggested and one piece of label and smaller size were preferable.

• Nuclear Engineering and Technology
• /
• v.45 no.3
• /
• pp.323-334
• /
• 2013

During a hypothetical core-disruptive accident (CDA) in a sodium-cooled fast reactor (SFR), degraded core materials can form roughly conically-shaped debris beds over the core-support structure and/or in the lower inlet plenum of the reactor vessel from rapid quenching and fragmentation of the core material pool. However, coolant boiling may ultimately lead to leveling of the debris bed, which is crucial to the relocation of the molten core and heat-removal capability of the debris bed. To clarify the mechanisms underlying this self-leveling behavior, a large number of experiments were performed within a variety of conditions in recent years, under the constructive collaboration between the Japan Atomic Energy Agency (JAEA) and Kyushu University (Japan). The present contribution synthesizes and gives detailed comparative analyses of those experiments. Effects of various experimental parameters that may have potential influence on the leveling process, such as boiling mode, particle size, particle density, particle shape, bubbling rate, water depth and column geometry, were investigated, thus giving a large palette of favorable data for the better understanding of CDAs, and improved verifications of computer models developed in advanced fast reactor safety analysis codes.

• Stress
• /
• v.26 no.4
• /
• pp.319-326
• /
• 2018

Background: This study investigated whether pre- and peri-disaster experiences influence on PostTraumatic Stress Disorder (PTSD) and whether post-disaster stress by life changes have impact on PTSD after controlling pre- and peri-disaster factors. Methods: Data came from a sample of 1,182 respondents who experienced natural disasters (flood and typhoon) in South Korea from 2012 to 2015. The SPSS Win 22.0 program was used for descriptive analysis, t-test, Chi-square test, Pearson's correlation and logistic regression analysis. Results: The results indicated that 24.3% of the disaster victims were in PTSD risk group. Compared with non-PTSD, PTSD risk group showed lower interpersonal trust and satisfaction, higher depression and anxiety, and lower subjective well-being. The results of hierarchical logistc regression revealed that all pre-, peri-, and post-disaster factors increased the probability of developing PTSD, except for relocation of residence. Moreover, a primary post-disaster predictor of PTSD was economic distress after controlling for pre- and peri-disaster. Conclusions: This study tested relative contributions of post-disaster factors on PTSD.