• The Korean Journal of Vision Science
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• v.20 no.4
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• pp.403-411
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• 2018

Purpose : The purpose of this study is to analyze how the certain efforts of the optical shops affect on opticians' job satisfaction and organizational commitment, and to analyze how opticians' job satisfaction and organizational commitment affect on the customer orientation and to suggest the method of maintaining competitiveness. Methods : Two hundred opticians took participations on the surveys via the Internet survey method and social network system (SNS), and SPSS 18.0 statistics program was used for data analysis; frequency analysis, T-test, factor analysis, reliability analysis, and multiple linear regression analysis were conducted. Results : It is analyzed the differences on the job satisfaction and organizational commitment in accordance with type of optical shops, conducting 5 working days/week and flexible time. As a result, higher job satisfaction is presented with 5 working days/week. Relationships with co-workers statistically affect on job satisfaction positively and emotional labor and work overload statistically affect on job satisfaction negatively. In addition, relationships with co-workers and reward statistically affect on organizational commitment positively and emotional labor and work overload statistically affect on organizational commitment negatively. And opticians' job satisfaction and organizational commitment statistically affect on customer satisfaction positively. Conclusion : It is necessary for the optical shops to make an effort for their opticians to improve the job satisfaction and organizational commitment. And to do so, it is needed to form trusting and respecting relationships with co-workers or superiors. In addition, it is necessary to have continuous communication and education for opticians' self-management. Also, it is needed to establish an effective reward system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.121-128
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• 2019

The purpose of this study was to investigate the effects of exercise program intervention in Korea for the control of blood sugar levels in elderly women patients undergoing diabetes mellitus typeII and to investigate the effects of exercise program intervention. Research methods were searched through RISS, KISS, KoreaMed, and KMbase as domestic databases and limited to domestic papers published from 2010 to May 2017. Diabetes, female diabetes, and diabetes mellitus typeII were used as the search terms related to the patient group. Programs related to intervention, intervention, exercise, blood glucose, glucose insufficiency, glucose control, fasting glucose and HbA1c were used. A total of 12 papers were provided according to the intervention method. The mediation period was 12 weeks(50%), 3 times per week(58.3%), and 50 to 69 minutes(83.4%) was the most. The combined aerobic and anaerobic exercise was found to be an effective exercise method to control not only blood glucose level but also HbA1c. Individualized exercise program intervention should be provided considering the physical fitness level and health status of elderly patients undergoing diabetes mellitus typeII and should be encouraged to maintain effective blood glucose control through continuous exercise rather than one-off exercise.

• Journal of Food Hygiene and Safety
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• v.34 no.1
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• pp.73-86
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• 2019

Seafaring is an important occupation that requires stringent hand hygiene practices as a basic method for preventing food-borne illness and infectious diseases when the diseases occur on board. The purpose of this study is to provide fundamental data for the prevention of food-borne illness and infectious disease on the ship by investigating the level of hand hygiene practices and influencing factors. A total of 222 seafarers were surveyed at a seafarers' educational institution between July and August 2017. Their hand hygiene practice were examined by a modified method using the guidelines which are recommended by the World Health Organization, the Centers for Disease Control and Prevention, and Hand Hygiene Australia. The mean of hand hygiene practice was 47.97 out of 75 points. By category, the most frequent hand hygiene practice was measured as 4.04 on a 5-point scale as 'after working'. Factors affecting hand hygiene practices were ship tonnage relating to in job characteristics, exercise in health-related characteristics, and soap in relation to the characteristics of the hand hygiene environment on board. To improve hand hygiene among seafarers, it is necessary to raise awareness of hand hygiene among seafarers who work on small ships in particular, and to improve the systems of hand hygiene on ships with continuous education, hygiene practice evaluation and feedback.

• Journal of Korea Technology Innovation Society
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• v.21 no.3
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• pp.938-968
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• 2018

Korea's basic research has been rapidly expended in both quantative and qualitative aspect since establishment of 'the Korea Science & Engineering Foundation' in 1977, proclaiming of 'the First Year of Basic Research Promotion' and enactment of 'the Basic Sciences Promotion Act' in 1989. Despite the continuous increment of government basic research funding, the problem of low perceptions of university researchers on the funding increment has been constantly raised. Based on an intrinsic review on the core issues are diagnosed based on Korean academics' basic research status analysis and future challenges are proposed based on the precedent diagnoses. The six key issues that need to take the next step in Korean academics' basic research are as follows: (1) basic research investment in universities, (2) appropriate research expenses for supporting individual researcher, (3) basic research funding allocation method, (4) maintaining the sustainable success rate of research projects, (5) systematic and strategic support for excellent researchers, (6) creating research-immersive environment. The five challenges to promote basic research in academics are as follows: (1) increasing in university research expenses, (2) diversification of basic research funding allocation method, (3) establishment of research field-specified support system and predictable principles, (4) stable and sufficient support for outstanding researchers, (5) reducing burden on research administration.

• Journal of the Korean Geotechnical Society
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• v.35 no.3
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• pp.17-24
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• 2019

The purpose of this study is to understand the characteristics of bearing capacity of shallow foundation on the grounds. We made a comparative study of existing bearing capacity theory, based on the three-dimensional finite element analysis with a variety of conditions such as ground condition, foundation scale and foundation shape. In the finite element analysis, the ultimate bearing capacity showed a gradual convergence in the form of exponential function or logarithm function according to the foundation scale. Although the shear strength increased, the bearing capacity tended not to increase but change linearly. In the results of comparative study of existing bearing capacity theory, bearing capacity ratio ($q_{u(FEA)}/q_{u(theory)}$) of pure sand has the outcome closest to those of the Terzaghi method. Pure clay turned out to be about 0.4~0.6 while normal soil was changed in a range of 0.3~1.3. As shear strength is increased, the results turned out to be less than 1.0. Bearing capacity ratio ($q_u/q_{u(1.0)}$), normalized at 1.0m bearing capacity, was about 35%, 15% and 5% of theoretical formula under the condition of ${\phi}=25^{\circ}$, $30^{\circ}$ and $35^{\circ}$ of pure sand; no scale effect was found with pure clay and the normal soil with lower soil strength level showed less than 10% of the theoretical formula of pure sand. Bearing capacity ratio of each case, in accordance with, the shear strength increase, was largely influenced by the internal friction angle. Shape factor of bearing capacity ratios classified by foundation shapes have different results according to the shapes; the shape factor of circular foundation is 1.50, square foundation is 1.30, rectangular and continuous foundations are 1.1~1.0.

• Clean Technology
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• v.27 no.2
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• pp.115-123
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• 2021

This study demonstrates a new method for the synthesis of organic-inorganic hybrid particles composed of an inorganic silica shell and organic core particles. The organic core particles are prepared with a uniform size using droplet-based microfluidic technology. In the process of preparing the organic core particles, uniform droplets are generated by independently controlling the flow rates of the dispersed phase containing photocurable resins and the continuous phase. After the generation of droplets in a microfluidic device, the droplets are photo-polymerized as particles by ultraviolet irradiation at the ends of microfluidic channels. The core particle is coated with a nano complex composed of polyallylamine hydrochloride (PAH) and phosphate ion (Pi) through strong non-covalent interactions such as hydrogen bonding and electrostatic interaction under optimized pH conditions. The polyamine nano complex rapidly induces the condensation reaction of silicic acid through the arranged amine groups of the main chain of PAH. Therefore, this method enabled the preparation of organic-inorganic hybrid particles coated with inorganic silica nanoparticles on the organic core. Finally, we demonstrated the synthesis of organic-inorganic hybrid particles in a short time under ambient and environmentally friendly conditions, and this is applicable to the production of organic-inorganic hybrid particles having various sizes and shapes.

• Journal of the Korean GEO-environmental Society
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• v.12 no.5
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• pp.59-63
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• 2011

Ground dynamic parameter such as shear elastic modulus and damping ratio is a very important variable in design of ground-structure with repeated load and dynamic load. Shear elastic modulus and damping ratio on small strain below linear limit strain is constant regardless of strain. Shear elastic modulus as the maximum shear elastic modulus and damping ratio as the minimum damping ratio were considered. As a lot of experiment related to the maximum shear elastic modulus, which is in dynamic deformation characteristics, have been conducted, many factors including voiding ratio, over consolidation ratio(OCR), confining pressure, geology time, PI, and the number of load cycle affect to dynamic soil characteristic. However, the research of ground dynamic characteristic improved with grout is absent such as underground continuous wall construction, deep mixing method, umbrella arch method. In order to investigate the dynamic soil characteristics improved with grout, in this study, resonant column tests were performed with changing water content(20%, 25%, 30%) and injection ratio of grout(5%, 10%, 15%), cure time(7th day, 28th day) As a result, shear elastic modulus and damping ratio, which are ground dynamic parameter, are affected by the injection ratio of milk grout, cure time and water content.

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.3
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• pp.183-198
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• 2021

The EPB (Earth Pressure Balanced) shield TBM method restrains the ground deformation through continuous excavation and support. Still, the significant surface settlement occurs due to the ground conditions, tunnel dimensions, and construction conditions. Therefore, it is necessary to clarify the settlement behavior with its influence factors and evaluate the possible settlement during construction. In this study, the analytical model of surface settlement based on the influence factors and their mechanisms were proposed. Then, the parametric study for controllable factors during excavation was conducted by numerical method. Through the numerical analysis, the settlement behavior according to the construction conditions was quantitatively derived. Then, the qualitative trend according to the ground conditions was visualized by coupling the numerical results with the analytical model of settlement. Based on the results of this study, it is expected to contribute to the derivation of the settlement prediction algorithm for EPB shield TBM excavation.

• Journal of the Korean Geotechnical Society
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• v.37 no.1
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• pp.29-41
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• 2021

Although underground works are essential to use underground spaces in urban areas efficiently, various damages caused by constructions have often occurred, making them major social problems. Since 2018, it is stipulated in the Special Act on Underground Safety Management that appropriate construction methods must be used in the design stage to prevent various damage cases. This Special Act includes establishing an area subject to underground safety impact assessment, analysis of ground and geological status, review of effects caused by changes in groundwater, review of ground safety, and establishment of measures to secure underground safety. This study area consists of various strata in order of landfill, sedimentary silt, sedimentary sand, sedimentary gravel, weathering zone, and foundation rock. Also, the slurry wall, a highly rigid underground continuous wall, was chosen as a construction method to consider high water table distribution and minimize the influence of the surroundings in this area. However, ground subsidence occurred on the road nearby in December 2019 due to the inflow of loosening soil to the construction area. Thus, several types of site investigations were conducted to suggest an appropriate analysis method and to find out loosed ground behavior and its area for the subsided site. As a result, new design soil properties were re-calculated, and the reinforcement measures were proposed through analytical verification.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.352-361
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• 2021

An underwater positioning method that can be applied to structures for underwater construction is being developed at the Korea Institute of Ocean Science and Technology. The method uses an extended Kalman filter (EKF) based on an inertial navigation system for precise and continuous position estimation. The observation matrix was configured to be variable in order to apply asynchronous measured sensor data in the correction step of the EKF. A Doppler velocity logger (DVL) can acquire signals only when attached to the bottom of an underwater structure, and it is difficult to install and recover. Therefore, a complex sensor device for underwater structure attachment was developed without a DVL in consideration of an underwater construction environment, installation location, system operation convenience, etc.. Its performance was verified through a water tank test. The results are the measured underwater position using an ultra-short baseline, the estimated position using only a position vector, and the estimated position using position/velocity vectors. The results were compared and evaluated using the circular error probability (CEP). As a result, the CEP of the USBL alone was 0.02 m, the CEP of the position estimation with only the position vector corrected was 3.76 m, and the CEP of the position estimation with the position and velocity vectors corrected was 0.06 m. Through this research, it was confirmed that stable underwater positioning can be carried out using asynchronous sensors without a DVL.