• Journal of the Korean Geotechnical Society
• /
• v.26 no.2
• /
• pp.45-54
• /
• 2010

The SCW numerical model described in the companion paper was used to carry out a comprehensive parametric study to evaluate the performance of the SCW. The five ground related parameters, which are porosity, hydraulic conductivity, thermal conductivity, specific heat, geothermal gradient, and five SCW design parameters, which are pumping rate, well depth, well diameter, dip tube diameter, bleeding rate, were used in the study. Two types of numerical simulations were performed. The first type was used to perform short-term (24-hour) simulation, while the second type 14 day simulation. The study results indicate that the parameters that have important influence on the performance of SCW were hydraulic conductivity, thermal conductivity, geothermal gradient, pumping rate, and bleeding rate. The thermal conductivity had the most important influence on the performance of the SCW. With the increase in the geothermal gradient, the performance increased in the heat mode, but decreased in the cooling mode. The hydraulic conductivity influenced the performance when the value was larger than $10^{-4}m/s$. The depth of the well increased the performance, but at the cost of increased cost of boring. The bleeding had an important influence on SCW, greatly enhancing the performance at a limited increased cost of operation. Overall, this study showed that various factors had a cumulative influence on the performance of the SCW, and a numerical simulation can be used to accurately predict the performance of the SCW.

• Korean Journal of Culture and Social Issue
• /
• v.16 no.2
• /
• pp.125-146
• /
• 2010

A total of 181 college students(61 males 121 females) with at least 5 years of living abroad (Returnee Group) and another group of 181 students (92 males and 93 females) without extended period of living abroad (Comparison Group) participated in the study by completing a questionnaire consisting of Acculturation Index, Multidimensional Acculturation Scale, Student Adaptation to College Questionnaire, Revised UCLA Loneliness Scale, CES-D, and WHOQOL. The results indicated that the Returnee Group, compared to the Comparison Group, reported as good adjustment toward college life in Korea and positive attitude toward the Korean identity, but a higher level of loneliness. When the Returnee Group were divided into 4 different groups on the basis of acculturation pattern, the Integration and Assimilation Type reported a better adjustment to college life, lower depression and loneliness and better quality of life than the Marginalization Type. The Mariginalization Type appears to be the most vulnerable group, experiencing difficulties in all areas of adjustment, and is clearly in need of interventions. Limitations of the present study and suggestions for future research were discussed.

• Publications of The Korean Astronomical Society
• /
• v.32 no.1
• /
• pp.225-230
• /
• 2017

The extragalactic background suggests half the energy generated by stars was reprocessed into the infrared (IR) by dust. At z~1.3, 90% of star formation is obscured by dust. To fully understand the cosmic star formation history, it is critical to investigate infrared emission. AKARI has made deep mid-IR observation using its continuous 9-band filters in the NEP field ($5.4deg^2$), using ~10% of the entire pointed observations available throughout its lifetime. However, there remain 11,000 AKARI infrared sources undetected with the previous CFHT/Megacam imaging (r ~25.9ABmag). Redshift and IR luminosity of these sources are unknown. These sources may contribute significantly to the cosmic star-formation rate density (CSFRD). For example, if they all lie at 1< z <2, the CSFRD will be twice as high at the epoch. We are carrying out deep imaging of the NEP field in 5 broad bands (g, r, i, z, and y) using Hyper Suprime-Camera (HSC), which has 1.5 deg field of view in diameter on Subaru 8m telescope. This will provide photometric redshift information, and thereby IR luminosity for the previously-undetected 11,000 faint AKARI IR sources. Combined with AKARI's mid-IR AGN/SF diagnosis, and accurate midIR luminosity measurement, this will allow a complete census of cosmic star-formation/AGN accretion history obscured by dust.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.17
• /
• pp.8003-8008
• /
• 2015

Background: The aim of this study was to investigate whether family history of cancer is associated with head and neck cancer risk in a Chinese population. Materials and Methods: This case-control study included 921 cases and 806 controls. Recruitment was from December 2010 to January 2015 in eight centers in East Asia. Controls were matched to cases with reference to sex, 5-year age group, ethnicity, and residence area at each of the centers. Results: We observed an increased risk of head and neck cancer due to first degree family history of head and neck cancer, but after adjustment for tobacco smoking, alcohol drinking and betel quid chewing the association was no longer apparent. The adjusted OR were 1.10 (95% CI=0.80-1.50) for family history of tobacco-related cancer and 0.96 (95%CI=0.75-1.24) for family history of any cancer with adjustment for tobacco, betel quid and alcohol habits. The ORs for having a first-degree relative with HNC were higher in all tobacco/alcohol subgroups. Conclusions: We did not observe a strong association between family history of head and neck cancer and head and neck cancer risk after taking into account lifestyle factors. Our study suggests that an increased risk due to family history of head and neck cancer may be due to shared risk factors. Further studies may be needed to assess the lifestyle factors of the relatives.

• Journal of agricultural medicine and community health
• /
• v.27 no.1
• /
• pp.87-98
• /
• 2002

This study is to reveal the overall level of loneliness, depression and social supports of the elderly in rural area of Korea. The interview survey was performed in February 2001 with structured questionnaires to 486 respondents of 65 years or more of age who lived in Muan-gun area. The questionnaire was the revised translation of Japanese Elderly Study Which was composed of general characteristics, Japanese Loneliness Scale, abridged General Depression Scale(GDS) and Duke University social support Inventory. The following analyses adopted the analysis of covariate, t-test, and Chi- squire were used for some of the cross- sectional analyses. Average age of 486 respondents was 73.9 years old. 58.0% of the respondents noticed their partner or son as the primary consultant for the stressful situation. 56.2% of the respondents experienced the loss of their marital partner, health and/or friends. Average score of loneliness, GDS and social supports of the respondents that was each $35.54{\pm}8.38$, $7.23{\pm}2.21$ and $26.01{\pm}.90$. The overall level of depression seemed to be low as the 'pleasure to be alive' and 'happiness' scored high while the 'state of anger' and 'ominous presentiment' scored low. The level of loneliness and depression was positively correlated while the relationships were negative between loneliness and support and between depression and social support. These results suggested that social and health promotional programmes be necessary for the elderly of rural area. Further research would be required to specify the necessities.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.24 no.3
• /
• pp.269-281
• /
• 2008

Fatigue or overload can result in mechanical problems of implant components. The mechanical strength in the implant system is dependent on several factors, such as screw and fixture diameters, material, and design of the fixture-abutment connection and abutment. In these factors, the last rules the strength and stability of the fixture-abutment assembly. There have been some previous reports on the mechanical strength of the fixture-abutment assembly with the compressive bending test or short-term cyclic loading test. However, it is restrictive to predict the long-term stability of the implant system with them. The purpose of this study was to evaluate the influence of the design of the fixture-abutment connection and abutment on the mechanical strength and failure mode by conducting the endurance limit test as well as the compressive bending strength test. Tests were performed according to a specified test(ISO/FDIS 14801) in 4 fixture-abutment assemblies of the Osstem implant system: an external butt joint with Cemented abutment (group BJT), an external butt joint with Safe abutment (group BJS), an internal conical joint with Solid abutment (group CJO), and an internal conical joint with ComOcta abutment (group CJT). The following conclusions were drawn within the limitation of this study. Compressive bending strengths were decreased in order of group BJS(1392.0N), group CJO(1261.8N), group BJT(1153.2N), and group CJT(1110.2N). There were no significant differences in compressive bending strengths between group BJT and group CJT(P>.05). Endurance limits were decreased in order of group CJO(600N), group CJT(453N), group BJS(360N), and group BJT(300N). 3. Compressive bending strengths were influenced by the connection and abutment design of the implant system, however endurance limits were affected more considerably by the connection design.

• Clinics in Shoulder and Elbow
• /
• v.12 no.2
• /
• pp.199-206
• /
• 2009

Purpose: Our goal for this study was to prospectively evaluate the functional & structural outcomes, by means of CT arthroscopy, of arthroscopic double-row fixation for treating rotator cuff tear. We also attempted to determine the variants that affect the functional & structural outcomes. Materials and Methods: Twenty seven consecutive patients underwent arthroscopic rotator cuff repair with double-row fixation. The average age at the time of the operation was fifty six years. The preoperative and postoperative examinations consisted of determining the Constant score, the score for the visual analogue scale for pain, the UCLA score, the American Shoulder and Elbow Surgeons (ASES) score, as well as a full physical examination of the shoulder. Preoperative MR arthrography was used to evaluate the integrity and atrophy of the rotator cuff. We measured the intraoperative tear size in the sagittal and coronal planes. Postoperative CT arthrography was used at one year postoperatively to evaluate the integrity and atrophy of the repaired tendons and muscles. Results: Preoperative MR arthrography revealed an average 29.22 mm tear size in the sagittal plane and an average 22.72 mm tear size in the coronal plane. Twelve cases of supraspinatus muscle atrophy and two cases of infraspinatus atrophy were observed on the preoperative MR arthrography. The average clinical outcome scores all significantly improved at the time of follow-up. At a mean of one year postoperatively, CT arthrography revealed 48.1% of the shoulders had healed, 11.1% showed incomplete healing and 40.7% showed retear of the repaired tendon. Conclusion: Arthroscopic double-row repair can result in improved clinical outcomes and good patient satisfaction. However, the problems about how to enhance healing of the repaired tendon still remain.