• Journal of Korean Society of Environmental Engineers
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• v.27 no.4
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• pp.369-376
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• 2005

This study aims to investigate and practically examine the effect of environmental qualifications based on the theoretical background on the area. On the basis of theoretical background, a study model was formulated in a way that the effect of qualifications in enterprises side is divided into an economic effect (improvement of productivity, improvement of qualifies of products) and non-economic effect (credibility on the job, expertise on techniques, assessment criteria on entrepreneurial value, applicability of job arrangement). Then, survey was carried out with questions designed in accordance with this model. The hypotheses were proved as the following. First, fir hypothesis 1(Environmental qualifications will bring up positive impacts on the economic effect of enterprises), it turned out to be true. The improvement of productivity and qualities of products were chose to represent the economic effect of entrepreneurs, and the both factors appeared to have positive impacts on the economic effect of enterprises. Second, for hypothesis 2(Environmental qualifications will have positive impacts on the non-economic effect of enterprises), it turned out to be true. Environmental qualifications were proved to have positive impacts on credibility on the job, expertise on techniques, assessment criteria on entrepreneurial value, applicability of job arrangement, which were introduced to represent the non-economic effect of enterprises. In conclusion, environmental qualifications were proved to have positive impacts on both economic and non-economic effect of enterprises.

• Journal of Nutrition and Health
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• v.31 no.9
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• pp.1446-1456
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• 1998

Bones are important parts in sustaining the shape of the body, but they are also metabolic organs which undergo bone remodeling by constant bone resorption and formation. Osteoporosis, the typical metabolic bone disease, is characterized by a reduction in bone mineral density (BMD). Women more than men are at risk fir osteoporosis-related fractures, especially in the lumbar spine, wrist, and hip region. Risk of fracture depends on one's BMD, which open determined by the peak bone mass value achieved at skeletal maturity and followed by subsequent age-and menopause-related bone loss. Genetic and environmental factors are known to play a key role in bone metabolism and diet is considered as one of the important environmental factors. The purpose of the present study was to assess the status of BMD and bone mineral content(BMC) to clarify the relationships between dietary intakes and the risk of osteoporosis in adult women in Taegu. Subjects were 130 healthy females in between 20 and 69 years of age. BMD and BMC of the lumbar spine(venebrae L2-4) of the subjects were measured by dual energy X-ray absorptiometry. The average age of the subjects was 47.4${\pm}$11.7 years old, the average weight was 57.2${\pm}$8.4kg, the average age of menarche was 16.6${\pm}$1.9 years old and the average age of menopause was 48.4${\pm}$5.3 years old. The nutrient intakes of the subjects measured by the convenient method were generally lower than the level of RDA. The result of nutrient intake assessed has shown that the average energy intake was 1701${\pm}$316kca1 which is 85.1% of the RDA and the average calcium intake was 485.4${\pm}$172.3mg which is 69.3% of the RDA. The intakes of protein, vitamin A, vitamin B$_1$, niacin were greater than the RDA, whereas the remaining nutrient intakes were lower than the RDA. The average BMD of the subjects was shown to be 1.06${\pm}$1.09g/$\textrm{cm}^2$. The highest BMD of 1.24${\pm}$0.14g/$\textrm{cm}^2$ was noticed in the subjects of 30s compared to 20s, 40s, 50s, 60s. The BMD values were compared by the relative body weight(R3W) of the menopause subjects, and it was found that the underweight group had significant lower BMB while the rest of the groups did not have any differences in BMD. The most strongly correlated nutrient with BMD among the menopause subjects appeared to be calcium. The women whose Ca intakes were higher than 500mg showed the significantly higher BMD than those with Ca intakes lower than 500mg. This study suggests that the most effective way to prevent osteoporosis and to reduce the incidences of fractures seems to be minimizing bone loss through the adequate intake of calcium as well as avoiding underweight, especially in menopausal women. (Korean J Nutrition 31(9) . 1446-1456, 1998)

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.1
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• pp.109-118
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• 2005

In the field of pediatric dentistry, comparison and analysis of cephalogram values of children are important fir evaluation of growth and development, and are essential to evaluate the craniofacial form and growth pattern for early diagnosis of malocclusion. For this, cephalographic norm values are important, but not many studies on the primary dentition exist. To compare the past norm values of normal occlusion in the primary dentition with current norms, preschool children, 4 to 5 years of age, with normal occlusion in the primary dentition who visited our hospital were examined. Among these children, 46 children with normal facial form and developmental status were chosen for evaluation of cephalogram values. The following results were as follows: 1. For skeletal values, the angular values showed no significant differences between males and females, and the linear values were generally greater in males than females. 2. SNA was $81.3^{\circ}$, SNB was $76.6^{\circ}$ and ANB difference was $4.7^{\circ}$. 3. The ratio for Mandibular body length to Anterior cranial base length was 0.9 : 1 for both male and female and the ratio for posterior facial height to anterior facial height was 61.4 % for male, 62.0 % for female. 4. For dental values, IMPA was $84.2^{\circ}$ and UA to SN was $90.8^{\circ}$. 5. The upper lip to Ricketts esthetic line was positioned 2.6 mm anteriorly, and the lower lip to Ricketts esthetic line was positioned 2.5 mm anteriorly.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.11 s.102
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• pp.1059-1066
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• 2005

This paper reports an application of Doherty amplifier for efficiency improvement of feedforward power amplifier(FPA). For performance analysis, we measured 15 W average output power using WCDMA 4FA input signal with a center frequency 2.14 GHz. The applied Doherty amplifier presents the characteristics of high efficiency and low linearity in comparison to the class AB amplifier, and it was used as main amplifier of FPA fir efficiency improvement. To analyze the change of characteristic, tow Doherty amplifiers whose linearity and efficiency are different were applied. The applied FPAs are improved about $2\%$ or more performance in efficiency, but decreased in linearity on 15 W average output power. We additionally modified the coupling factor(CF) of the error loop and the error amplifier capacity for linearity improvement. Aa a result, the efficiency improvement and high linearity resulted from the change of CF and error amplifier capacity. However, we think if the linearity of Doherty amplifier were more than 35 dBc, the FPA would improve the performance about $2\%$ or more efficiency and maintain enough linearity.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.11 s.102
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• pp.1075-1085
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• 2005

The purpose of this paper is to design the architecture for synchronization of MB-OFDM UWB system that is being processed the standardization for Alt-PHY of WPAN(Wireless Personal Area Network) at IEEE802.15.3a and to analyze the implementation loss due to 4 parallel synchronization architecture for design or link margin. First an overview of the MB-OFDM UWB system based on IEEE802.15.3a Alt-PHY standard is described. The effects of non-ideal transmission conditions of the MB-OFDM UWB system including carrier frequency offset and sampling clock offset are analyzed to design a full digital architecture for synchronization. The synchronization architecture using 4-parallel structure is then proposed to consider the VLSI implementation including algorithms for carrier frequency offset and sampling clock offset to minimize the effects of synchronization errors. The overall performance degradation due to the proposed synchronization architecture is simulated to be with maximum 3.08 dB of the ideal receiver in maximum carrier frequency offset and sampling clock offset tolerance fir MB-OFDM UWB system.

• Journal of the Korean Geotechnical Society
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• v.21 no.2
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• pp.57-65
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• 2005

Geotextile have been used for the past 30 years for various types of containers, such as small sandbag, 3-D fabric forms and aggregate filled gabion etc. While they are mainly used for flood and water control, they are also used against beach erosion fir shore protection. Especially, large-sized geotextile tube structures are used in various innovative coastal systems involving breakwaters. This paper presents the hydrodynamic behavior of geotextile tubes based on the results of hydraulic model tests. These tube are generally about 1.0 m to 2.0 m in diameter, thou띤 they can be sized for any application. The tubes can be used solely, or stacked to add greater height and usability. Stacked geotextile tubes will be created by adding the height necessary for some breakwaters and embankment, therefore increasing the usability of geotextile tubes. The hydraulic model test was conducted as structural condition and wave conditions. Structural condition is installation direction to the wave (perpendicular and 45$^{circ}$$), and wave condition is varied with the significant wave height ranging from 3.0 m to 6.0 m. Compared with previous test result, the stacked geotextile tube is more stable against wave attack than single tube. Also, the case of none-water depth above crest is more stable than 0.5H of water depth above crest. The incline installed stacked tube is more effective for wave adsorption.

• Journal of the Korean Vacuum Society
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• v.7 no.1
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• pp.66-71
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• 1998

Two kinds of $Ga_2S_3:Er$ (type A and type B) single crystals were grown by the chemical transport reaction method using iodine as a transport agent. The single crystals were crystallized into a monoclinic structure. The optical energy band gaps were found to 3.375 eV for the $Ga_2S_3:Er$ (type A) single crystal and 3.365 eV fir the $Ga_2S_3:Er$ (type B) single crystal at 13K. When the $Ga_2S_3:Er$ (type A and type B) single crystals were excited by the 325 nm-line of a Cd-He laser, Photoluminescence spectra of the $Ga_2S_3:Er$ (type A) single crystal exhibited blue emission band peaked at 444 nm and green and red emission bands peaked at 518 nm and 690 nm. Pgitikynubescebce soectra if the $Ga_2S_3:Er$ (typeB) single crystal showed green and red emission bands peaked at 513 nm and 695 nm. Sharp emission peaks in the two kinds if $Ga_2S_3:Er$ single crystal were observed near 525 nm, 553 nm, 664 nm, 812 nm, 986 nm, and 1540 nm and analysed as originating from the electron transitions between the energy levels of $Er^{3+}$ ion.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.1
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• pp.15-22
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• 2002

This study was conducted from April 13 to October 8, 2001 in Jeju to determine the influence of cutting height (2, 4, 6, 8 and 10 cm from the soil surface) on growth, forage yield and chemical composition of kenaf (Hibiscus cannabinus L.). As cutting height was increased from 2 to 10 cm, plant height averaged across two cuttings increased from 157.7 to 184.7 cm. This pattern held fir the number of leaves and branches per plant, stem diameter and plant weight per plant. As cutting height increased from 2 to 10 cm, fresh forage, dry matter, crude protein and TDN yields increased from 85.5 to 113.7MT/ha, from 11.97 to 15.63 MT/ha, from 1.63 to 2.72, and from 4.95 to 7.54 MT/ha, respectively. As cutting height was increased from 2 cm to 10 cm, crude protein, ether extract, nitrogen free extract, and TDN contents increased from 14.2 to 17.6%, 2.9 to 3.9%, 24.2 to 25.8% and 43.1 to 48.5%, respectively, while crude fiber and crude ash contents decreased from 35.5 to 30.4 % and 9.9 to 8.1 %, respectively.

• Journal of the Korean Geographical Society
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• v.48 no.5
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• pp.651-666
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• 2013

The objective of this study is to introduce the characteristics and establishing process of national regional policy for the sunbelt developmentr initiative of the southern coastal area in Korea. Discussion on the development of southern coastal area of Korea with some members of the Korea Society of Future Studies began in the early 1990s, and its discussion was continued with the activities by the Committee on Regional Unity of the Grand National Party and Namhaean Forum. The sunbelt development initiative was selected as one of the major commitments of the Grand National Party in the 17th presidential election of Korea. Since the launching of the Lee Myung-bak government, the Presidential Committee on Balanced National Development made a comprehensive plan for sunbelt development of southern coastal area(CPSD), and this plan was confirmed by central governmental planning in May 2010. CPSD is meaningful in terms of the fir first national regional planning and legal plan in Korea. The target year of CPSD is 2020, and some projects by CPSD started in 2010. However, there are many negative views that CPSD will not be going too well. Therefore, new efforts and roles of geographers who participated in the process of planning of CPSD are required for the success of CPSD.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.5
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• pp.675-686
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• 2007

Statement of problem: Titanium nitride(TiN) coatings are the most general and popular coating method and used to improve the properties of metallic surface for industrial purposes. When TiN coating applied to the abutment screw, frictional resistance would be reduced, as a results, the greater preload and prevention of the screw loosening could be expected. Purpose: The purpose of this study was to investigate mechanical properties of TiN coated film of various coating thickness on the titanium alloy surface and to evaluate proper coating thickness. Material and method: 95 Titanium alloy (Ti-6Al-4V) discs of 15 mm in diameter and 3 mm in thickness were prepared for TiN coating and divided into 7 groups in this study. Acceding to coating deposition time (CDT) with TiN by using Arc ion plating, were divided into 7 groups : Group A (CDT 30min), Group B (CDT 60min), Group C (CDT 90min), Group D (CDT 120min), Group E (CDT 150min), Group F(CDT 180min) and Group G (no CDT) as a control group. TiN coating surface was observed with Atomic Force Microscope(AFM), field emission scanning electron microscopy(FE-SEM) and examined with scratch tester, wear tester. Result: 1. Coating thickness fir each coated group was increased in proportion to coating deposition time. 2. Surface of all coated groups except Group A was homogeneous and smooth. However, surface of none coated Group G had scratch. 3. Adhesion strength for each coated group was increased in proportion to coating deposition time. 4. Wear resistance for each coated group was increased in proportion to coating deposition time. 5. Surface roughness in Group A, B, C was increased in proportion to coating deposition time. But, surface roughness in Group D, E, F was showed decreased tendency in proportion to coating deposition time. Conclusion: According to coating deposition time, mechanical properties of TiN coated film were changed. It was considered that 120 minutes coating deposition time ($1.32{\mu}m$ in coating thickness) is necessary.