• Korean Journal of Agricultural Science
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• v.14 no.1
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• pp.1-15
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• 1987

This experiment was conducted to investigate the effect of nitrogen top-dressing and Jangyeopkong was planted under two different seeding time (single cropping-May 15, after barley cropping-June 18), four levels of nitrogen top-dressing (0, 3, 6, 9 kg/10a) and two times of nitrogen top-dressing (Hilling time, Flowering Time). The results obtained are summarized as follow: 1. The days to flowering and maturity were delayed a day longer in hilling times than flowering times of nitrogen top-dressing. 2. The number of nodes of main stem and length of internodes didn't show significance among treatments. But, the number of nodes of branches was much higher when the soybean was planted on May 15, and were higher hilling time than flowering time as the amount of nitrogen top-dressing increased. Especially, the number of nodes of branches was high when 6kg of nitrogen was applied during hilling time. 3. The fresh and dry weight of stem and leaves at 10, 25 and 40 days after flowering were increased by increasing the amount of nitrogen top-dressing. More apparent effect of nitrogen was attained high significant when nitrogen was applied at the time of hilling rather than flowering time. 4. The number and fresh weight of nodule, and dry weight were apparently decreased after barley and were decreased according to the increasing the amount of nitrogen top dressing. The degrees of decreasing was more apparent in the hilling time than in the flowering time. 5. The number of pods per plant, and number and weight of grain per plant were higher when the soybean was planted on May 15, the amount of top dressing increased and hilling time rather than flowering time. Especially, yield component were highest when 6kg of nitrogen was applied during hilling time. Also, the grain yield per 10a showed high significance among treatment, and were high when 6kg of nitrogen was applied during hilling time.

• Journal of the Korean Orthopaedic Association
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• v.54 no.3
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• pp.261-268
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• 2019

Purpose: The authors measured the anteversion of the femoral neck and acetabulum and the sum of the two values in normal Korean people by computed tomography. The authors examined the normal range of the values to analyze the difference in sex and sides as well as the relationship between the femoral neck and acetabular anteversion. Materials and Methods: The authors measured the anteversion of the femoral neck and acetabulum in 118 normal Korean adult males and 114 females aged between 21 and 49 on both the right and left sides by computed tomography and calculated the sum of anteversion. The authors analyzed the mean and standard deviation, and investigated the sex differences and side differences, as well as the relationship between the acetabular anteversion and femoral neck anteversion statistically. Results: The anteversion of the acetabulum in males was 15.3°±6.1° on the right side and 15.3°±6.6° on the left side. The anteversion of the femoral neck in males was 5.3°±7.6° on the right side and 1.5°±9.2° on the left side according to the Hernandez et al. method. The anteversion of acetabulum in females was 16.8°±5.4° on the right side and 16.3°±5.8° on the left side. The anteversion of femoral neck in females was 10.3°±8.2° on the right side and 7.9°±8.2° on the left side according to Hernandez et al. method. No difference in acetabular anteversion, and a significant difference in the femoral neck anteversion on both the right and left sides were observed between males and females. No difference of acetabular anteversion was observed between the right and left sides, but a significant difference in femoral neck anteversion was noted between the right and left sides measured by either the Hernandez et al. method or Weiner et al. method. The Pearson coefficient revealed no correlation between the femoral neck anteversion and acetabular anteversion. Conclusion: No difference in the acetabular anteversion was observed, but there was a significant difference in femoral neck anteversion between males and females. A significant difference in femoral neck anteversion was observed between the right and left sides. No correlation was noted between the anteversion of the femoral neck and acetabulum.

• The Optical Journal
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• v.11 no.5 s.63
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• pp.47-51
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• 1999

• The Optical Journal
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• v.11 no.4 s.62
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• pp.26-29
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• 1999

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.3
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• pp.483-488
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• 2003

Nasopalatine duct cyst(NPDC) is the most common non-odontogenic cyst in the oral area and is thought to be originated from the epithelial remnants of the nasopalatine duct. Many etiologic factors have been proposed for the NPDC; trauma to the region during mastication or from ill fitting dentures, bacterial infection, and spontaneous proliferation of tissue. The majority of cases are seen between the ages of 40th and 60th and it is rare in children. Surgical enucleation is the recommended treatment for NPDC, usually under general anaesthesia. A 9-year-old boy was refered to the chosun university pedodontics clinic that this child who has anterior palatal swelling is in routine check. In this case, swelling was presented at the bottom of the anterior nasal cavity as well as in the labial aspect of the upper alveolar ridge. It was so large that we treated it by marsupialization and obturator was put. This patient is on the continuous observation. We treated the child who had NPDC by marsupialization, and got the successful results such as rapid bone regeneration and the consistency of incisor vitality.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.2
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• pp.9-16
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• 2008

To assess the preference and efficacy of empirical fitting methods with spheric and aspheric RGP lenses. Methods: Healthy 37 subjects were fitted with spheric design (diameter 9.3 mm) on right eye and aspheric design (dia 9.6 mm) on the left eye. Base curves which were fitted empirically (using on-K, Kavg-0.50D (or 1.00D) and manufacturer's recommended fitting guide) were compared with another base curve which obtained the best diagnostic fit with spheric and aspheric RGP lenses. The preference and fitting type (lid attachment or interpalpebral) for two design lenses were investigated 2 weeks after fitting RGP lenses. Results: Of 33 successful RGP lens-wearing subjects, 76% preferred spheric design compared with 24% of aspheric RGP lens wearers. Sixty seven percent were fitted with lid-attachment in spheric lenses, whereas 64% were fitted with lid-attachment in aspheric lenses. The acceptable fit success rates within ${\pm}$0.50D of base curves were 97% for the on-K fit, 100% for the Kavg-0.50D fit and 100% of the manufacturer's guide fit compared with the diagnostic fit in spheric design, whereas 91%, 79% and 94% reported on-K, Kavg-1.00D and manufacturer's guide, respectively, in aspheric design. Conclusions: Although aspheric RGP lenses are more popular in the Korean market, it is still preferable to fit subjects with spheric RGP lenses. Empirical fitting may be best accomplished with the spheric lenses using Kavg-0.50D fit and the manufacturer's fitting guide, whereas aspheric RGP lens designs are unacceptable lens fit based on empirical fitting.

• School Mathematics
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• v.15 no.4
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• pp.723-742
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• 2013

The purpose of this study was to analyze children's proportional reasoning process on an ill-structured "architectural drawing" problem solving and to investigate their level and characteristics of proportional reasoning. As results, they showed various perspective and several level of proportional reasoning such as illogical, additive, multiplicative, and functional approach. Furthermore, they showed their expanded proportional reasoning from the early stage of perception of various types of quantities and their proportional relation in the problem to application stage of their expanded and generalized relation. Students should be encouraged to develop proportional reasoning by experiencing various quantity in ration and proportion situations.

• The Optical Journal
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• s.154
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• pp.33-45
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• 2014

■ 광통신용 렌즈는 광통신 시스템에 있어서 송신단과 수신단에 사용되는 하나의 부품으로 집광/발산의 결상 기능을 지니며, 광회로 부품과 광섬유 또는 수발광소자인 LD/PD와 광섬유를 효율 좋게 저손실로 접속하는 기능을 수행함. ■ 마이크로 렌즈는 마이크로 광학의 분야에 있어 광의 집광 및 평행 광으로의 변환에 빠질 수 없는 가장 기본적인 소자로서, 마이크로 렌즈의 종류로는 마이크로 볼 렌즈, 비구면 렌즈와 GRIN 렌즈가 대표적으로 있음. ■ 렌즈에 적용되는 사양으로서 렌즈의 유효 구경, 초점(focal point), 주점(principle point), 주점에서 초점까지의 거리인 초점 거리(focal length), 가상의 법선을 기준으로 빛이 입사되는 각도인 입사각, 빛이 다른 매질을 만나 반사되는 각도인 반사각, 서로 다른 매질을 빛이 통과할 때 굴절하는 굴절각 등이 있음. ■ 렌즈 모듈의 구조는 렌즈, 스페이서(spacer), 아리리스(Iris), 백링(back-ring), 바렐(Barrel)로 구성함. ■ LD 모듈에서 광원에 패브리 페로(FP)로 사용하는 것에는 볼 렌즈가, DFB 광원으로 사용하는 것으로는 비구면 렌즈가 사용하고 있음. 이를 위해 PON용에서는 G-PON의 OLT, ONU 측, GE-PON의 OLT측에는 비구면 렌즈가 사용되나 GE-PON의 ONU측에는 볼 렌즈가 주로 사용되고 있음. ■ 2012년 볼 렌즈 시장은 수량 기반으로 2011년 대비 9.7% 증가한 7,350만 개, 금액기반으로는 17.0% 증가한 3,125만$를 기록하였음. ■ 2012년 비구면 렌즈 시장은 수량 기반으로 2011년 대비 22.0% 증가한 2,220만 개, 금액 기반으로는 32.0% 증가한 8,900만$를 기록하였음. ■ 2012년 광통신용 렌즈 시장(볼 + 비구면)은 수량 기반으로 2011년 대비 12.3% 증가한 9,570만 개, 금액 기반으로는 27.7% 증가한 1억 2,063만$이었음.

• The Journal of the Korea Contents Association
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• v.14 no.3
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• pp.463-469
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• 2014

Safety related devices unconstrained temporally in the process of operation of nuclear power plants could be damaged by the sliding during seismic activity. In this study sliding response of unconstrained objects to the base excitations is studied experimentally and analytically. In experiments static and dynamic tests to determine the coefficient of friction and the shaking table experiments to verify the sliding response of the analytic results were conducted. Numerical solutions by solving the nonlinear differential equations of motion governing sliding were found by the computer program using the step by step acceleration method. The exact solutions of the sliding response to the simple forms of base excitations were found to verify the computer program developed in this study. Relative displacement envelopes were suggested as a colliding criteria of the unconstrained objects.

• Proceedings of the Optical Society of Korea Conference
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• 2002.07a
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• pp.212-213
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• 2002

최근에 국내에서도 광학장비개발에 대한 관심이 급속도로 증가하고 있다. 광학장비개발기술의 핵심은 렌즈설계 능력에 달려있다고 해도 과언이 아니다. 더구나 현재 발전추세를 보면 소형 경량화 장비의 개발을 위해 다양한 수단과 방법을 동원하고 있는 실정이다. 특히 렌즈설계에 의한 소형 경량화 목표를 달성하기 위하여 비구면 렌즈 및 회절렌즈의 사용이 불가피하다고 할 수 있다. 본 논문에서는 장파장 적외선 영역에서의 비구면 및 회절면의 사용에 의한 렌즈 성능에 미치는 영향을 분석하여 보았다. (중략)