• Anxiety and mood
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• v.9 no.2
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• pp.128-134
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• 2013

Objective : As treatments for breast cancer require long period of time, the patients need continuous monitoring and management of their health related quality of life. The purpose of this preliminary study is to explore the utility of monitoring quality of life using a mobile phone based application, which was developed to enable the patients to report daily quality of life more efficiently. Methods : Department of psychiatry, breast cancer center and U-health team of Asan Medical Center collaborated in developing a mobile application titled 'DugunDugun'. Through the application, patients with breast cancer receiving neo-adjuvant chemotherapy could report on various questions about their daily quality of life. We extracted and explored the daily basis of the data of sleep duration, number of awake, sleep satisfaction, mood and anxiety from nine patients who reported on the questionnaire for more than a month. Results : The longitudinal data collected using our mobile application well represented the characteristics of individual sleep patterns and daily emotional changes. Most of the patients showed high daily variations in the scores of their quality of life while their averaged scores were similar among patients. The patient with highest daily variations in the subjective sleep quality and daily emotional change had highest score corresponding to moderate depression in Beck Depression Inventory (BDI). Conclusion : The results suggest that mobile application could be a useful tool for monitoring and collecting the daily quality of life in the patients with breast cancer. We expect that mobile application could facilitate early detection and proper intervention for the cancer patients at psychological crisis.

• Korean Journal of Ecology and Environment
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• v.41 no.3
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• pp.301-310
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• 2008

This study was to analyze characteristics of fish compositions and longitudinal distribution, based on trophic and tolerance guild at 22 sampling sites of Yeongsan River watershed during 2003$\sim$2006, and also to compare before and after the estuary dam construction. The collected fishes, based on catch per unit effort (CPUE), were 44 species in the watershed and dominant fishes were Zacco platypus, Acheilognathus macropeterus, Zacco temminckii and Carassius auratus. According to comparative analysis of fish in the non polluted sites (NPS) vs. polluted sites (PS), the number of species and individuals was lower by 70% in the PS than the NPS, indicating ecological degradations by chemical pollutions or/and habitat modifications. The relative abundance of sensitive and insectivore species decreased as the stream order increases, while tolerant and omnivore species increased with the stream order. In this survey, largemouth bass (Micropterus salmoides), which is a top-carnivore and exotic species, may influence trophic guild system throughout active predations on endemic species, resulting in modifications of ecological functions. The construction of estuary dam on Yeongsan River in 1981 resulted in wider lacustrine zone and desalinated through limitation of seawater input. These physical changes have caused increases of lentic dwelling species and limited fish migrations (i.e., eel). Overall, fish fauna and composition analyses showed that the number of species and individuals in this water body may be reduced due to inputs of pollutants from the watershed, habitat modifications, and increases of exotic species (largemouth bass). For these reasons, effective lake management strategies are required for the ecosystem conservation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.6
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• pp.567-573
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• 2015

This paper aims to evaluate the variation in the mechanical properties of carbon/epoxy composites under in situ low- and high-temperature environments. In situ low- and high-temperature environments were simulated with temperature ranging from $-40^{\circ}C$ to $220^{\circ}C$ using an environmental chamber and furnace. The variation in the mechanical properties of the composites was measured for longitudinal and transverse tensile properties, in-plane shear properties and interlaminar shear strength. Under the low temperature of $-40^{\circ}C$, all mechanical properties increased moderately compared to the baseline properties measured at room temperature. The changes in the longitudinal tensile properties decreased moderately with increasing temperature. However, transverse tensile properties, in-plane shear properties and interlaminar shear strength each showed a significant drop due to the glass transition behavior of the matrix after $140^{\circ}C$. Notably, the tensile property value near $100^{\circ}C$ increased compared to baseline property value, which was an unusual occurrence. This behavior was a direct result of post-curing of the epoxy resin due to its exposure to high temperature.

• The korean journal of orthodontics
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• v.26 no.5 s.58
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• pp.557-568
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• 1996

The purpose of this study was to analyze the growth changes of ODI and APDI with age on the three facial growth patterns. The biennial serial cephalometric radiographs of 19 male and 14 famale samples with normal occlusion during 10 years were used in this study. The samples were divided into three groups - drop type, neutral type, forward type - by the total change of the Y-axis during the periods of the study. The findings in this investigation indicated the following: 1. The mean values and standard deviations of each age group in each facial type of male and famale were obtained. 2. The difference of ODI and APDI among the 3 facial types was not significant through all observed ages(P)0.05). The size of ODI appeared large consistently in order of the drop, neutral, and forward type in both male and female through all observed ages. 3. The ODI and APDI were maintained without any charges with age during the periods of the study(p>0.05). 4. In correlation analysis between the total change of the Y-axis and 6 measurements, the AB plane angle and facial angle showed correlation in both male and female(p<0.05), the APDl in only female(p<0.001), but the ODI not appeared correlation in either male or female(p>0.05).

• Journal of the Korean Society for Railway
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• v.20 no.2
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• pp.241-247
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• 2017

Railway bridges with continuously welded rail have a limitation of span length due to track-bridge interaction. In order to overcome this, a sliding slab track system has been developed that comprises with a low-frictional sliding layer between the bridge deck and the track slab to isolate the longitudinal behavior between the bridge and the track. In this study, a real scale track system is prepared to experimentally evaluate the longitudinal frictional behavior. Applied loading rates were 0.2, 1.0, 5.0 and 10mm/min; vertical mass on the track are track slab only, 5,000 and 10,000kg added mass, respectively. Test results showed that the resulting frictional coefficients varied from 0.22 to 0.33. In addition, 10,000 cycle loadings were applied to simulate repetitive sliding to represent 30 years of service life. The frictional coefficient increase was measured and found to be 7% of that of the initial loading stage, which means that the sliding layer is adequate to provide low-frictional behavior for the sliding slab track system. Effects of changes of the frictional coefficient of the sliding layer were analyzed by rail-structure interaction analysis.

• Journal of the Korean Data and Information Science Society
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• v.27 no.4
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• pp.1013-1025
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• 2016

The purpose of this study was to analyze longitudinal effect of physical education activity (PEA) score on self-rated health evaluation change (SHEC). This study used hierarchical linear and nonlinear models to investigate of the SHEC during the transition into adolescence (from middle school 1st to high school 2nd grade). Using the Korea children and youth panel survey (KCYPA), data were collected over the course of five years (from 2010 and 2014). HLM 6.8 computer program was used to analyze the data. The result were as follows. First, boys' SHEC increased across the five years, and girls' SHEC decreased across the five years. Second, boys' the self-rated health was increased across the three years and decreased across the two years. Third, girls' the self-rated health was increased across the two years and decreased across the three years. Fourth, the PEA score of 1st grade of high school showed a significant positive association with the boys' SHEC. Fifth, the PEA score of 1st grade of middle school showed a significant negative association with the girls' SHEC.

• Ecology and Resilient Infrastructure
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• v.1 no.2
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• pp.49-60
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• 2014

Fish assemblages play an integral role in stream ecosystem and are influenced by stream environmental conditions and habitat disturbances. Fish community structures and habitat parameters of U.S. EPA rapid bio-assessment protocol were surveyed to investigate the effect of stream environment and habitat disturbance on fish communities at 13 study sites in the Gapyeong Stream, a typical gravel-bed stream. Principal component analysis (PCA) based on data from habitat assessment at each study site indicated that the study sites were differentiated by habitat parameters such as embeddedness, velocity/depth regime and sediment deposition, which were related with bed slope. A total of 46 species belonging to 12 families were collected in the Gapyeong Stream. A dominant species was Zacco koreanus, subdominant species was Z. platypus. Hierarchical cluster analysis based on species abundance classified fish communities into the three main groups along the stream longitudinal change. Non-metric multidimensional scaling (NMDS) portrayed that fish community structures were related to major habitat parameters, i.e., epifaunal substrate/available cover, embeddedness, velocity/depth regime, sediment deposition, channel alternation and frequency of riffles. These results suggested that fish community structures were primary affected by the longitudinal environmental changes, and those were modified by habitat disturbance in the Gapyeong Stream, a gravel-bed stream.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.594-600
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• 2016

The present study numerically investigated the gas leakage characteristics in a simplified underground combined cycle power plant. The effect of obstacles near a crack location on the gas concentration in the confined space was analyzed by using the lower flammable limit (LFL) of methane gas. When the jet flow was close to the vertical walls, the longitudinal leakage distance increased by about 60% (when an obstacles was present) compared to the case without any obstacle, because these obstacles prevented transverse flows. In addition, when an air filter was installed near to the trajectory of the gas flow, the longitudinal leakage distance was similar to the distance between the crack and obstacle, whereas the transverse leakage distance increased up to 8 times compared to the case without any obstacle. As the jet flow impacts on the obstacle and changes its direction, the gas flows recirculate. Therefore, it is necessary to consider the effect of the structure and facility locations on the trajectory of the jet flow to propose an accident prevention system in confined spaces.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.509-519
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• 2016

This study intends to examine how the subjective health perception of drinkers influences the depression trajectory change by using longitudinal data for elderly drinkers. This study has set up a balanced panel by combining the results from "Aging study panel research" conducted in the year 2006 (1st), 2008 (2nd), 2010 (3rd), 2012 (4th). A total of 543 elderly drinkers, who have responded to each research have been selected as targets for the final analysis. In the analyses, descriptive statistics and Latent Growth Modeling were conducted to examine the causal relationship between the observed and latent variables. The results are as follows: First, it was found that there was a negative correlation-with statistical significance-between the initial value of subjective health perception and the initial status of depression symptom. Second, there was a positive correlation between the initial value of subjective health perception and the changes of depression symptom. This indicates that elderly drinkers with high health perception usually have high degree of depression change; however, this does not mean it was statistically significant. Third, there was a statistically significant correlation between subjective health perception change and depression symptom change. It was found that the depression change level would be low if the subjective health perception change level was high. Thus, we can assume that the depression symptoms of elderly drinker c would slow down if the subjective health perception level increases.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.118-124
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• 2017

In this study, a numerical simulation was performed using commercial code Fluent(v.17.1). The underground Combined Cycle Power Plant (CCPP) was simplified to analyze the methane gas leakage with the crack size and position. In addition, extensive numerical simulations were carried out for different crack sizes from 10 mm to 20 mm. The crack position is the gas leakage, which is assumed to be near the pipe elbow and the gas turbine. A total of 4 cases were compared and analyzed. To analyze the gas leakage, the concept of the Lower Flammable Limit (LFL) was applied. The leakage distance was defined in the longitudinal direction, and the transverse direction was estimated and quantitatively analyzed. As a result, the leakage distance in the longitudinal direction varies by 52.3 % depending on the crack size at the same crack position. Moreover, the maximum difference was 34.8 % according to the crack position when the crack sizes are identical. As jet flow impacts on the obstacle and changes its direction, the recirculation flows are formed. These results are expected to provide useful data to optimize the location and number of gas detections in confined spaces, such as underground CCPP.