• 한국해양공학회지
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• 제18권2호
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• pp.77-82
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• 2004

The purpose of this study is to develop a nesting algorithm, using a genetic algorithm to optimize nesting order, and modified No Fit Polygon(NFP) methodology to place parts with the order generated from the previous genetic algorithm. Various genetic algorithm techniques, which have thus far been applied to the Travelling Salesman Problem, were tested. The partially mapped crossover method, the inversion method for mutation, the elitist strategy, and the linear scaling method of fitness value were selected to optimize the nesting order. A modified NFP methodology, with improved searching capability for non-convex polygon, was applied repeatedly to the placement of parts according to the order generated from previous genetic algorithm. Modified NFP, combined with the genetic algorithms that have been proven in TSP, were applied to the nesting problem. For two example cases, the combined nesting algorithm, proposed in this study, shows better results than that from previous studies.

• 전기전자학회논문지
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• 제22권2호
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• pp.510-513
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• 2018

최근 전자파 적합성(EMC: electromagnetic compatibility)의 중요성이 매우 높아짐에 따라 칩 수준에서의 전자파 간섭(EMI: electromagnetic interference) 측정이 자주 요구되고 있다. IEC 61967 및 IEC 62508에서 규정된 근거리 전자장 스캐닝(NFS: near-field scanning) 시스템은 칩 레벨에서의 전자파 간섭을 분석하는 대표적인 방법이다. 칩이 점점 고속화되면서 근거리 전자장 스캐닝 시스템의 측정 주파수는 광대역화되어야 하지만 근거리 전자장 탐침(NFP: near-field probe)의 신호 대 잡음 비(SNR: signal-to-noise ratio)가 저하된다는 문제가 있다. 본 논문에서는 근거리 전자장 스캐닝 시스템에서 광대역 특성을 가지면서도 잡음 대 성능 비를 향상시키는 기술에 대해 살펴본다.

• 한국CDE학회논문집
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• 제2권3호
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• pp.195-210
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• 1997

In Rapid Prototyping process, the time required to build multiple prototype parts can be reduced by packing several parts optimally in a work volume. Interactive arrangement of the multiple parts is a tedious process and does not guarantee the optimal placement of all the parts. In this case, packing is a kind of 3-D nesting problem because parts are represented by STL files with 3-D information. 3-D nesting is well known to be a problem requiring an intense computation and an efficient algorithm to solve the problem is still under investigation. This paper proposes that packing 3-D parts can be simplified into a 2-D irregular polygon nesting problem by using the characteristic of rapid prototyping process that the process uses 2-dimensional slicing data of the parts and that slice of the STL parts are composed of polygons. Our algorithm uses no-fit-polygon (NFP) to place each slice without overlapping other slices in the same z-level. The allowable position of one part at a fixed orientation for given parts already packed can be determined by obtaining the union of all NFP's that are obtained from each slice of the part. Genetic algorithm is used to determine the order of parts to be placed and orientations of each part for the optimal packing. Optimal orientation of a part is determined while rotating it about the axis normal to the slice by finite angles and flipping upside down. This algorithm can be applied to any rapid prototyping process that does not need support structures.

• 지역사회간호학회지
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• 제4권2호
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• pp.170-187
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• 1993

The natural growth rate of the Korean population has decreased from 3.0% in 1960 to 1.0% in 1990. This was done with family planning program which was introduced by the government in 1961. The family planning program focused on birth control rather than the characteristics of the individuals and motivations of contraception. People were simply forced to use the method. Whereas, Natural Contraceptive is a method of family planning based solely on the timing of intercourse with the naturally occurring' physiological manifestation of fertilization and in fertilization during the menstrual cycle. This is the combination of self fertility awareness with periodic abstinence. Natural family .planning(NFP) programs in Korea were first started in the Chun-Chen diocese of catholic church by Bishop Thomas Stewart in 1970 In 1975, the Bishops conference launched the Korea Happy Family Movement in the Catholic Hospital Association, to promote the natural family planning. An average of 70,000 people, including adolescents, college students, unmarried and married persons, arid the clergies were trained during a six-year period (1986-1991). 61.5%(24,542 people) of those who completed 3 cycles during 6 year period (1986-1991) became autonomous users and the range was from 48.1% to 78.2%. In 1986, 22.7% of NFP individuals who drooped out of the program because of the desire for conception (23.4%), the difficulty of the method used(25.8%), and the loss of interest(22.8%). During the six-year period the unplanned pregnancy rate at the NFP was 2.9%. The range of the pregnancy rate was at 1.2-9.8%. The rate was decreased as years passed. The major reason for the failure of contraceptive was error by the individuals(61.1%). The percentage of the success of conception was 18.1% of 2.979 for achieving pregnancy. The highest percentage was 58.2% (99 users) in Kwang-Joo diocese and next was 37.1% (10 users) in Chong Joo diocese.

• 한국전산구조공학회논문집
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• 제37권2호
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• pp.119-131
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• 2024

일반적으로 속도 펄스를 가진 지반운동이 속도 펄스가 없는 지반운동에 비하여 구조물에 보다 큰 손상을 줄 수 있다고 알려져 있다. 지진가속도기록으로부터 속도 펄스의 유무의 판정과 이를 정량화하는 연구가 현재 많이 진행되어 오고 있다. 기존 지진기록들을 단층으로 떨어진 거리를 기준으로 원거리 지진과 근거리 지진으로 구분하였다. 또한, 근거리 지진은 속도 펄스의 유무를 정량화하여 펄스를 가진 지진과 펄스를 가지지 않은 지진으로 구분하였다. 최종적으로 각 지진그룹별로 40개의 원거리지진, 40개의 속도 펄스를 가진 근거리 지진과 40개의 속도 펄스를 가지지 않은 근거리 지진을 선정하였으며, 총 120개 지진가속도 기록을 지진취약도 평가를 위한 지진해석에 사용하였다. 세 그룹의 지진을 이용하여 납-고무받침과 탄성받침을 가진 두 종류의 예제교량에 대한 지진응답을 평가하여 확률론적 지진요구도 모델을 작성하였다. 확률론적 지진요구도 모델을 이용하여 지진취약도 해석을 수행하여 속도 펄스의 유무에 따른 지진취약도 영향을 분석하였다. 지진파의 속도 펄스 유무에 따른 지진취약도 곡선의 비교 결과로부터, 속도 펄스를 가진 지진의 지진취약도가 속도 펄스가 없는 지진의 지진취약도가 약 3배~5배 정도 정도 크게 나타난다. 이는 속도 펄스를 가진 지진의 경우가 그렇지 않은 지진의 경우에 비하여 교량의 손상 피해가 크다는 것을 의미한다.

• East Asian mathematical journal
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• 제31권5호
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• pp.737-742
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• 2015

In this paper, we consider a generalized fractional robust optimization problem (FP). Establishing a nonfractional optimization problem (NFP) equivalent to (FP), we establish necessary optimality conditions and duality results.

• East Asian mathematical journal
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• 제31권3호
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• pp.345-349
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• 2015

In this paper, we consider a fractional robust optimization problem (FP) and give necessary optimality theorems for (FP). Establishing a nonfractional optimization problem (NFP) equivalent to (FP), we formulate a Mond-Weir type dual problem for (FP) and prove duality theorems for (FP).

• 대한소아치과학회지
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• 제21권2호
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• pp.439-455
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• 1994

생리적 치근 흡수가 뒤따르는 유치 치주인대의 신경분포 및 변화를 평가하기 위하여 생후 1, 2. 3. 4. 5개월된 개의 유치 치주인대와 9개월된 영구치 치주인대를 대상으로 neurofilament protein(NFP) 을 이용한 면역조직화학적 방법으로 관찰하여 다음과 같은 결과를 얻었다. ${\bullet}$ 유견 유치의 치주인대 신경분포는 치근단 1/3 부위에서 가장 밀집되어 있었으며 치근 중앙부로 향할수록 현저하게 감소되었으며 전체적으로 그 분포밀도 및 분지 정도는 영구치와 비교시 약한 양상을 나타냈다. ${\bullet}$ 구치부에 비해 전치부에서 신경분포가 보다 발달된 양상을 보였으며 구치 치근이개부 치주인대에서는 신경섬유가 관찰되지 않았다. ${\bullet}$ 유치근이 흡수됨에 따라 신경분포 정도도 감소되었으며 탈락시기의 치근 주위에서는 신경섬유를 관찰할 수 없었다. ${\bullet}$ 치은점막상피의 신경지배는 치아가 발육함에 따라 감소되는 양상을 나타내었으며 설측점막이 순측점막보다 더 발달된 신경분포 양상을 관찰할 수 있었다. ${\bullet}$ 유치 치주인대 신경말단 형태는 수지상의 신경말단 형태를 나타내고 있었으며 전형적인 Ruffini 신경말단은 거의 관찰할 수 없었다. 이상의 결과를 미루어 신경섬유의 분포는 기능과 밀접한 관계가 있는 것으로 생각되고 더우기 유치의 생리적 치근흡수에 따른 치주인대에 신경섬유의 분포 및 변화는 유치의 성장발육에 따른 하나의 변화라고 생각된다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제36권5호
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• pp.360-365
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• 2010

Introduction: Mammalian tooth pulp is densely innervated by sensory nerves that are mostly C fibers and A delta fibers. However, there is evidence suggesting that many unmyelinated axons in the pulp are in fact parent meylinated axons. Immunohistochemical staining for neurofilament protein 200 kDa (NFP200) was performed to identify the demyelinated but parent myelinated axons. Materials and Methods: The pulp was removed from healthy premolars and 3rd molars extracted from juveniles and adults undergoing orthodontic treatment, and immunohistochemical staining were applied with NPF200 antibodies, which specifically dye myelinated axons. The specimens underwent an electron microscopy examination with diaminobenzidine (DAB) immunostaining after observation and analysis by fluorescence and confocal laser scanning microscopy. Results: The NPF200 immuno-positive axons in the radicular pulp areas were observed as bundles of many nerve fibers. Many small bundles were formed with fewer axons when firing to the coronal pulp areas and then reachrd a different direction. In the radicular pulp, unmyelinated axons and myelinated axons were present together. However, in the coronal pulp, unmyelinated axons were most common and NFP200 immuno-positive unmyelinated axons with a larger diameter than those in the radicular pulp were observed more frequently. On the other hand, most of the immuno-positive unmyelinated fibers were similar in size to that of typically well-known unmyelinated fibers. Conclusion: Myelinated fibers innervated to the dental pulp maintain their myelins in the radicular portion, but these fibers lost myelins in the coronal portion. After the loss of myelin, the size of the axoplasm also decreased.

• Biotechnology and Bioprocess Engineering:BBE
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• 제7권6호
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• pp.340-346
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• 2002

The purpose of the present study was to examine the efficacy and mechanism of the PAB (para-amino benzamidine) affinity column chromatography, Viresolve NFP virus filtration, pasteurization (60$\^{C}$ heat treatment for 10 h), and lyophilization steps employed in the manufacture of urokinase from human urine as regards the removal and/or inactivation of the hepatitis A virus (HAV). Samples from the relevant stages of the production process were spiked with HAV and subjected to scale-down processes mimicking the manufacture of urokinase Samples were collected at each step, immediately titrated using a 50% tissue culture infectious dose (TCID$\_$50/), and the virus reduction factors evaluated. PAB chromatography was found to be an effective step for removing HAV with a log reduction factor of 3.24. HAV infectivity was rarely detected in the urokinase fraction, while most of the HAV infectivity was recovered in the unbound and wash fractions. HAV was completely removed during the Viresolve NFP filtration with a log reduction factor of $\geq$ 4.60. Pasteurization was also found to be an effective step in inactivating HAV where the titers were reduced from an initial titer of 7.18 log$\_$10/ TCID$\_$50/ to undetectable levels within 10 h of treatment. The log reduction factor achieved during pasteurization was $\geq$ 4.76. Lyophilization revealed the lowest efficacy for inactivating HAV with a log reduction factor of 1.48. The cumulative log reduction factor was $\geq$ 14.08. Accordingly, these results indicate that the production process for urokinase exhibited a sufficient HAV reducing capacity to achieve a high margin of virus safety.