• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.557-562
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• 2005

The field scale experiment was performed to examine the effect of plant coverage on the constructed wetland performance and recommend the optimum development and management of macrophyte communities. Four sets(each set of 0.88ha) of wetland (0.8ha) and pond(0.08ha) systems were used. Water flowing into the Seokmoon estuarine reservoir from the Dangjin stream was pumped into wetland system. Water depth was maintained at $0.3{\sim}0.5m$ and hydraulic retention time was managed to about $2{\sim}5$ days; emergent plants were allowed to grow in the wetlands. After three growing seasons of the construction of wetlands, plant coverage was about 95%, even with no plantation, from bare soil surfaces at the initial stage. Dead vegetation affected nitrogen removal during winter because it is a source of organic carbon which is an essential parameter in denitrification. Biomass harvesting is not a realistic management option for most constructed wetland systems because it could only slightly increase the removal rate and provide a minor nitrogen removal pathway due to lack of organic carbon.

• Archives of Reconstructive Microsurgery
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• v.16 no.2
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• pp.86-92
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• 2007

Failure of reattachment of finger is inevitable in replantation surgery and that failure rate is about 10 % are reported in many authors. Management of the failed finger replantation is challenge to microsurgeons. We report 7 cases of thumb reconstruction after failure of replantation. The reconstructive surgery composed with early debridement of soft tissue that are under gangrenous processing, extract the phalangeal bone without any soft tissues. Osteosynthesis of the extracted phalangeal bone with host phalangeal bone. The exposed bony portion covered with vascularized flaps such as reverse radial forearm pedicled flap, free radial forearm flap and neurovascular island finger flap. This procedure underwent within a week after vascular insufficiency developed. All of the flaps are survived, bone union achieved within 3 months. The function and external appearance of the reconstructed thumb were encouraging; pinch power was average 1.2 pounds. Early removal of necrotizing soft tissue followed by covering none vascular phalangeal bone which extracted from the dead phalanx with vascularized flap is one of the useful alterative solutions in failed replantation surgery in hand.

• Korean Journal of Head & Neck Oncology
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• v.4 no.1
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• pp.21-28
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• 1988

Skin replacement in large cheek defects after excision of benign or malignant tumor on the face is a challenging task. The physical characteristics of cheek skin are matched best by adjacent skin. Various methods of reconstructing of the facial surface such as forehead flap, distant flap, or a full thickness or split thickness skin graft have replaced adjacent tissue for coverage in many cases. We have reviewed ten cases of aesthetic reconstruction of the face after resection of the facial skin tumor within the last 5 years. The first group of 3 patients were reconstructed with split thickness skin graft from the scalp or lower abdomen. The second group of patients were reconstructed with cheek flap. The third group of 3 patients were reconstructed with cervicofacial flap. The last 2 patients were reconstructed with nasolabial flap & island falp respectively. The advantages from our experience with various method of coverage are its hidden donor area & good color match with the facial skin & increased success rate.

• Health Policy and Management
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• v.10 no.1
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• pp.57-94
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• 2000

Korea's social health insurance system was introduced in 1977, which has made a universal coverage possibly by July 1989. Korean government had pursued a single objective for the last decade to put the whole population under the coverage of medical security, and the objective was achieved within 12 years. The rapid accomplishment is primarily due to such factors as limited benefits, high copayment rate, low contributions as well as rapid economic growth. There are several sources of pressure for the implementation of social health insurance such as health professional group, labor unions, politicians, international organizations etc.. However it is important to look at the feasibility of social health insurance. Among other things, it is necessary to identify the administrative infrastructure of insurance system and to assess income for source of fund. As many developed countries, Korea began to apply health insurance to the employees of the large firms, and the expansion based on employment status. Thus the several funds system was inevitable according to the gradual expansion strategy. However many persons had criticized several funds system in respect with equity and efficiency aspects. In the short history of the Korean health insurance, whether one fund or sever or funds had been the most controversial issue. In Febrary 1999, the National Assembly passed the act of one fund system. From July 2000 separate funds will be unifed under new health insurance scheme. In this study we will analyze the policy making process on implementation, expansion and integration of health insurance system of Korea. And also analyse problems related to policy making.

• Journal of the Korean Ceramic Society
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• v.46 no.2
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• pp.146-154
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• 2009

It is necessary to minimize the thickness of Ni inner electrode layer and to improve the coverage of inner electrode, for the purpose of developing the ultra high-capacity multi layered ceramic capacitor (MLCC). Thus, low temperature sintering of dielectric $BaTiO_3$ ceramic should be precedently investigated. In this work, the relationship between dielectric properties of MLCC and batch condition such as mixing and milling methods was investigated in the $BaTiO_3$(BT)-Dy-Mg-Ba system with borosilicate glass as a sintering agent. In addition, several chip properties of MLCC manufactured by low temperature sintering were compared with conventionally manufactured MLCC. It was found that low temperature sintered MLCC showed better DC-bias property and lower aging rate. It was also confirmed that the thickness of Ni inner electrode layer became thinner and the coverage of inner electrode was improved through low temperature sintering.

• Journal of the Optical Society of Korea
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• v.19 no.5
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• pp.514-520
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• 2015

This paper presents a novel shore-to-sea maritime data transmission system based on time-code diversity, using visible light in maritime environments to overcome the limitations of conventional maritime wireless communications. The proposed system is primarily comprised of existing LED-based lighthouses and maritime transceivers (marine beacons, buoys, etc.), and thus is considered cost-effective in terms of implementation. We first analyze maritime visible-light communications on the basis of the unique properties of a maritime environment, i.e. sea states (wave height, wind speed, etc.), plus atmospheric turbulence, using the Pierson-Moskowitz (PM) and JONSWAP (JS) spectrum models. It is found that the JS model outperforms the PM model, and that the coverage distance depends on the LED power and sea states. To combat maritime fading conditions that significantly degrade performance and coverage distance, we propose a time-code diversity (TCD) scheme in which the delayed versions of the original data are retransmitted using orthogonal Walsh codes. This TCD scheme is found to be superior, in that it offers three orders of magnitude in terms of BER performance, compared to a conventional (non-TCD) transmission scheme. The proposed scheme is robust and efficient in overcoming the effect of impairments present in maritime environments with a BER of approximately $10^{-5}$and a data rate of 100 Kbps at a distance of 1 km.

• Corrosion Science and Technology
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• v.2 no.2
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• pp.82-87
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• 2003

Stress corrosion cracking of Alloy 600 and Alloy 690 has been studied with a C-ring specimen in 1%, 10% and 40% NaOH at $315^{\circ}C$. SCC test was performed at 200 mV above corrosion potential. Initial stress on the apex of C-ring specimen was varied from 300 MPa to 565 MPa. Materials were heat treated at various temperatures. SCC resistance of Ni-$_\chi$Cr-10Fe alloy increased as the Cr content of the alloy increased if the density of an intergranular carbide were comparable. SCC resistance of Alloy 600 increased in caustic solution as the product of coverage of an intergranular carbide in grain boundary, intergranular carbide thickness and Cr concentration at grain boundary increased. Low temperature mill annealed Alloy 600 with small grain size and without intergranular carbide was most susceptible to SCC. TT Alloy 690 was most resistant to SCC due to the high value of the product of coverage of an intergranular carbide in grain boundary, intergranular carbide thickness and Cr concentration at grain boundary. Dependency of SCC rate on stress and NaOH concentration was obtained.

• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.7
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• pp.1036-1042
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• 2002

The purpose of this study was to set up the sizing system for clothes of lower body. Sample size was 191 females and their age ranges were from 19 to 24 years old. The lower body types for the sizing system were categorised by height and drop value of lower body(hip circumference-waist circumference). The results were as follows. 1. The Thick waist (drop value of lower body<21) and the Slender waist (drop value of lower body$\geq$27) had the low coverage rates of 14.2% and 11.5%, and the Normal waist (21$\leq$ drop value of lower body<27) had the high coverage rate of 72.8%. 2. The height could be divided into three groups and thar covered 97.5%. The Short(152cm) covered 2l.0%, the Regular(160cm) 58.7% and the Tall(168cm) 17.8%. 3. The size interval of hip circumference was 4cm and the intervals of waist circumference were 3cm and 4cm. The interval of slacks length was 4∼5cm according to three height groups.

• Journal of the Korean Society of Clothing and Textiles
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• v.44 no.6
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• pp.1139-1153
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• 2020

Upper body types were classified to develop the sizing system of the cycling wear top for the high school male cyclist. The research methods were performed using the anthropometric measurements of 111 high school male cyclists that included cluster analysis was performed. The research results are as follows. Type 1 (23.4%) has the longest biocromion length, is the tallest of the three types and a proper body type. Type 2 (25.2%) has the largest weight and developed muscles in the chest parts. Type 3 (51.4%) is the shortest of the three types and is a skinny body with a bending back. In order to develop a sizing system, the 12 anthropometric measurements were selected for correlation analysis. The bust circumference and stature were presented as the control dimensions of sizing system. The waist front, waist back length and biacromion length were less correlated with other items; consequently, they were independent items and were set as referable dimensions. Therefore, it was proposed as a sizing system because the 5 cm of bust and 5 cm of stature have a high coverage by body type. The total coverage rate was 81.9%.

• Korean Journal of Metals and Materials
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• v.46 no.5
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• pp.296-303
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• 2008

Hydrogen permeation through dense palladium-based membranes has attracted the attention of many scientists largely due to their unmatched potential as hydrogen-selective membranes for membrane reactor applications. Although it is well known that the permeation mechanism of hydrogen through Pd involves various processes such as dissociative adsorption, transitions to and from the bulk Pd, diffusion within Pd, and recombinative desorption, it is still unclear which process mainly limits hydrogen permeation at a given temperature and hydrogen partial pressure. In this study, we report an all-electron density-functional theory study of hydrogen permeation through Pd membrane (using VASP code). Especially, we focus on the variation of the energy barrier of the penetration process from the surface to the bulk with hydrogen coverage, which means the large reduction of the fracture stress in the brittle crack propagation considering Griffith's criterion. It is also found that the penetration energy barrier from the surface to the bulk largely decreases so that it almost vanishes at the coverage 1.25, which means that the penetration process cannot be the rate determining process.