• Journal of Life Science
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• v.19 no.7
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• pp.892-898
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• 2009

MIF is a progesterone analogue and is known as a potent progesterone antagonist. Although MIF has been known to inhibit prostate cancer cell growth, its molecular mechanisms are not yet clear. In the present study, when the cells were treated for 2-4 days with 5-40 $\mu$M of MIF, the growth and viability of LNCaP cells were significantly decreased in a dose- and time-dependent manner. When the cells, cultivated in a normal 2 mM calcium concentration medium, were treated with 15 $\mu$M MIF for 1 day, the intracellular calcium level increased by 26% compared to the control. Similar results were also found in cells located in the calcium-free reaction buffer, indicating that MIF induced the increase of intracellular Ca$^{2+}$ levels, regardless of the presence of calcium in the surrounding medium. In the cells treated with various concentrations of MIF, the intracellular calcium levels increased in a dose dependent manner. Cells treated with MIF revealed typical early apoptotic signs, i.e., chromosome condensation and nuclei fragmentation. In cells treated with 40 11M MIF, Bcl-2 decreased to 19% of the control. The expression of Bax increased to almost 2 fold of the control. These results demonstrated very clearly that MIF treatment blocks the expression of Bcl-2 but stimulates the expression of Bax. According to the results of the present investigation, the apoptotic mechanism of MIF is triggered by intracellular modulation.

• Korean Chemical Engineering Research
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• v.45 no.3
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• pp.249-257
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• 2007

The periodic square wave (PSW) model was successfully applied to the optimal design of a batch-storage network. The network structure can cover any type of batch production, distribution and inventory system, including recycle streams. Here we extend the coverage of the PSW model to multitasking semi-continuous processes as well as pure continuous and batch processes. In previous solutions obtained using the PSW model, the feedstock composition and product yield were treated as known constants. This constraint is relaxed in the present work, which treats the feedstock composition and product yield as free variables to be optimized. This modification makes it possible to deal with the pooling problem commonly encountered in oil refinery processes. Despite the greater complexity that arises when the feedstock composition and product yield are free variables, the PSW model still gives analytic lot sizing equations. The ability of the proposed method to determine the optimal plant design is demonstrated through the example of a high density polyethylene (HDPE) plant. Based on the analytical optimality results, we propose a practical process optimality measure that can be used for any kind of process. This measure facilitates direct comparison of the performance of multiple processes, and hence is a useful tool for diagnosing the status of process systems. The result that the cost of a process is proportional to the square root of average flow rate is similar to the well-known six-tenths factor rule in plant design.

• Journal of Biomedical Engineering Research
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• v.21 no.3 s.61
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• pp.239-246
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• 2000

In this paper. we propose a semi-automatic segmentation algorithm to extract organ in 3D medical data by using a manually segmentation result in a sing1e slice. Generally region glowing based tracking method consists of 3 steps object projection. seed extraction and boundary decision by region growing. But because the boundary between organs in medical data is vague, improper seeds make the boundary dig into the organ or extend to the false region. In the proposed algorithm seeds are carefully extracted to find suitable boundaries between organs after region growing. And the jagged boundary at low gradient region after region growing is corrected by post-processing using Fourier descriptor. Also two-path tracking make it possible to catch up newly appeared areas. The proposed algorithm provides satisfactory results in segmenting 1 mm distance kidneys from X-rav CT body image set of 82 slices.

• Journal of Science Education
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• v.33 no.1
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• pp.44-55
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• 2009

The research is aimed at investigating the development and application of high school biology classes utilizing discourse-typed inquiry learning program fitted with POE, and the corresponding effect on student's academic achievement and attitude toward science. 4 classes of 11th graders in a general high school located in Busan were selected as subjects. Biology I, 'Circulation' unit was lectured for 4 weeks (6 classes), and the experimental group underwent classes utilizing discourse-typed inquiry learning program fitted with POE. The control group was taught identical major learning contents, but based on the learning objectives and research activities provided by Biology I textbook. As a result of application, first, the discourse-typed inquiry learning program fitted with POE exhibited positive consequences of linking previously acquired knowledge and the new learning attained through experiments, as well as not only improving the students' problem solving capacity through diverging questions from the teachers to drive the students' higher-level contemplation, but also enhancing student academic achievement by assisting their logical thinking. Second, POE-fitted discourse-typed inquiry learning program rendered presupposing session of the experiment that resulted in drawing learners' attention in advance, and incited active participation in the learning process through solving the contradiction between what was actually observed and what was expected, which eventually proved to lay out positive impact on students' attitude toward science.

• Journal of the Korean association of regional geographers
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• v.14 no.5
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• pp.492-506
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• 2008

This paper aims to explore the characteristics of regional network of Korean firms in Dalian City, China, which is focused on social, cultural and institutional characteristics. To achieve this goal, the paper attempts to analyze the supply of raw material and parts, sales and cooperative relations of the firms. Among Korean firms in Dalian City, the characteristic of non-local network can be seen in supply enterprise of raw material, parts and semi products. On the other hand, a tighter local network relationship can be seen in sales. Large companies appear stronger in non-local network than small businesses and small businesses are stronger in local network. In terms of cooperation among enterprises, many firms have networks of joint marketing, joint use of equipments, exchange of techniques and information with the supply enterprise. With the customer enterprise, there is a network in joint marketing and manpower training. Especially, most of the customer enterprises are Chinese ones, which have extensive networks in big cities, such as in Beijing, Shanghai, Guangzhou, Tianjin and Dalian. In local network, the Korean firms in Dalian cooperate in product development, finance and manpower training with local firms. And in non-local cooperation, Korean firms are active in tech support, information exchange and R&D.

• Journal of Elementary Mathematics Education in Korea
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• v.12 no.1
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• pp.79-100
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• 2008

Freudenthal has advocated the reinvention method. In that method, the pupils start with a meaningful context, not ready-made concepts, and invent informative method through which he could arrive at the formative concepts progressively. In many face the reinvention method is contrary to the traditional method. In traditional method, which was named as 'concretization method' by Freudenthal, the pupils start with ready-made concepts, and applicate this concepts to various instances through which he could arrive at the understanding progressively. Through analysis, it turns out that Korea's seventh elementary mathematics textbook is based on concretization method. In this thesis, first of all, I will reconstruct probability unit of seventh elementary textbook according to Freudenthal's reinvention method. Next, I will perform teaching experiment which is ruled by new lesson design. Lastly, I analysed the effects of teaching experiment. Through this study, I obtained the following results and suggestions. First, the reinvention method is effective on the teaching of probability concept and algorithm. Second, in comparison with current textbook strand, my strand which made probability concept go ahead and combinatorics concept let behind is not deficiency. Third, tree diagram is effective matrix which contribute to formalization of combinatorics calculation. Lastly, except for fraction, diverse representation of probability, for example percentage or informal ratio expression must be introduced in teaching process.

• Archives of design research
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• v.12 no.4
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• pp.61-68
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• 1999

Most of the time, developers spend their energy to analyze the main function of the system or make source codes. As a result, they can not consider user interface on their own system and this is true in most programmer's world. But we want to consider the design concept in developing mechanism. In this case we have to upgrade the legacy system which maintaining the transmission system using the copper cables, and add the transmission system using the optical fiber cables. Therefore we design the user interface make easy for end users who are using the maintaining system on copper cables not to confuse the new system which include optical fibers. Especially, we are consider the developing model of design policy and real user to make easy to use new system. In this paper we will describe the instance to adapt the design concept on Broadband Access Network Operation Support System.

• Journal of Chest Surgery
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• v.42 no.6
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• pp.807-812
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• 2009

The late Professor Lee CB (1915~1967) was one of the pioneers in the early stages of thoracic surgery in Korea while he was in charge of the Department of Thoracic and Cardiovascular Surgery at Seoul National University hospital as the first director from 1957 until he died of liver cancer in 1967. He was a graduate from the old Seoul National University, and he dedicated himself to the field of lung surgery after he joined the army during the Korean War, which broke out in 1950. Among his many contributions to pulmonary surgery, he performed the first partial lung resection in Korea in 1953. His lecture notes were recently found. These lecture notes for medical students were written by hand in late 1950s, Considering the content and form of the lecture notes, they are thought to have very significant historical value. The lecture notes were a total of 277 pages on general thoracic surgery and cardiovascular surgery with 75 self-drawn figures. This study was intended to facilitate a better understanding of the history of thoracic surgery in Korea, and especially for young thoracic surgeons. These notes may well contribute to the field of Thoracic and Cardiovascular Surgery in Korea.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.10a
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• pp.70-72
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• 1998

1. 서론 : 최근에 폐수나 지하수 및 음용수에 존재하는 휘발성 유기화합물(Volatile Prganic Compound, VOC)는 심각한 환경오염이 주범이 되고 있다. 이러한 문제를 해결하는 방법으로 흡착, 증류, air stripping 등의 여러 가지 분리기술이 제시되어 왔다. 그러나 전통적인 방법들은 분리된 오염물질이 제2의 상으로 전이된다는 점에서 또 다른 분리공정을 필요로 하는 단점을 지니고 있다. 이에 반해 투과증발공정은 추가적인 분리과정이 없이 효율적으로 오염된 물속의 유기용매를 제거한다는 점에서 많은 관심을 모으고 있다. 이미 알려진 이러한 VOC 제거에는 소수성이면서 고무상인 고분자가 우수한 특성을 가지는 것으로 밝혀졌고 그 중에서 실록산계 고분자가 아주 효과적인 것으로 알려져 있다. 그러나 이러한 실록산계 고분자는 기계적 강도가 약하여 필름의 박막형성능력이 떨어지는 것으로 알려져 있어 이러한 단점을 보완하기 위해 가교구조의 도입이나 공중합체의 구조를 도입하는 연구가 많이 수행되어 왔다. 이러한 연구의 한 방법으로 실록산-아미드공중합체를 이용하여 투과증발에 적용한 연구는 수행되어 왔다. 이들의 제막방법으로 주로 실록산다이아민/방향족다이아민의 비를 달리하거나 실록산다이아민의 분자량의 변화를 달리하면서 실록산-이미드 블록 또는 그래프트중합체를 제조하는 방법을 사용하였다. 이 실험에서는 주로 실록산-이미드의 비율이 낮아지면 유기용매의 선택성에서 물의 선택성으로 바뀌는 percolation point가 관찰되며 이것은 실록산-이미드의 비율이 낮을수록 물속의 유기용매의 제거에 유리하다는 것을 보여준다. 이에 따라 실록산다이아민과 다이안하이드라이드만을 사용한 실록산이미드막이 추천되나 여기에 대한 투과특성연구는 전혀 이루어지지 않았다.정육점이었고 백화점과 재래닭 사육장에서 직접구입도 하고 있었다. 구입 동기는 가족들이 좋아하고 영양가를 생각한다가 62%였으며 구입정보는 주위사람의 권유로 구입하고 있었다. $\bigcirc$ 구입할 때 중점적으로 살펴보는 사항은 신선도와 순수재래종 여부, 위생상태였다. 한편 소비자가 언제나 구입할 수 없다는 의견이 85.2%나 되어 원활한 공급과 시장조성이 아직 정착되지 않고 있었다. $\bigcirc$ 현재 유통되고 있는 재래종닭은 소비자 대부분이 잡종으로 인식하고 있었으며, 재래종과 일반육계와의 구별은 깃털색, 피부색, 정강이색등 외관상으로 구별하고 있었다. 체중에 대한 반응은 너무 작다는 의견이었고, 식품으로의 인식도는 비교적 고급식품으로 인식하고 있다. $\bigcirc$ 재래종닭고기의 브랜드화에 대한 견해는 젊고 소득이 높은 계층에서 브랜드화의 필요성을 강조하고 있다. $\bigcirc$ 재래종달걀의 소비형태는 대부분의 소비자가 좋아하였으나 아직 먹어보지 못한 응답자가 많았다. 재래종달걀의 맛에 대해서는 고소하고 독특하여 차별성을 느끼고 있었다. $\bigcirc$ 재래종달걀의 구입장소는 계란판매점(축협.농협), 슈퍼, 백화점, 재래닭 사육 농장등 다양하였으며 포장단위는 10개를 가장 선호하였고, 포장재료는 종이, 플라스틱, 짚의 순으로 좋아하였다. $\bigcirc$ 달걀의 가격은 200원정도를 적정하다고 하였으며, 크기는 (평균 52g)는 가장 적당하다고 인식하고 있으며, 난각색은 대부분의 응답자가 갈색을 선호하였다. $\bigcirc$ 재래종달걀의 구입시 애로사항은 믿을수 없고, 구입장소를 몰라서, 값

• Journal of Food Hygiene and Safety
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• v.29 no.4
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• pp.253-259
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• 2014

This study was conducted to investigate survival of Bacillus cereus (B. cereus) on stainless steel and polyvinyl chloride (PVC) and its transfer from two material to lettuce. The stainless steel and PVC were innoculated with B. cereus and stored at 6 combination conditions (temperature : $20^{\circ}C$ and $30^{\circ}C$, relative humidity (RH) : 43%, 69%, and 100%). Although the total numbers of B. cereus at RH 43% and RH 69% were reduced by 3.53-4.00 log CFU/coupon within 24 h regardless of material type, the spore numbers of B. cereus was lasted at 3.0 log CFU/coupon. When two materials were stored at $30^{\circ}C$, RH 100%, the spore numbers of B. cereus was rapidly increased by 3.0 log CFU/coupon. In addition, the reduction rate of B. cereus was decreased in the presence of organic matter. Transfer rate of B. cereus from surface of stainless steel and PVC to lettuce was increased by 10 times in the presence of water on the lettuce surface. As a result of this study, the presence of B. cereus on produce contact surfaces can increase the risk of cross-contamination. Thus, it is important that the packing table and conveyer belt in post harvest facility should be properly washed and sanitized after working to prevent cross-contamination.