• Kyungpook Mathematical Journal
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• 제48권2호
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• pp.287-302
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• 2008

The vertex set of a digraph D is denoted by V (D). A c-partite tournament is an orientation of a complete c-partite graph. A digraph D is called cycle complementary if there exist two vertex disjoint cycles $C_1$ and $C_2$ such that V(D) = $V(C_1)\;{\cup}\;V(C_2)$, and a multipartite tournament D is called weakly cycle complementary if there exist two vertex disjoint cycles $C_1$ and $C_2$ such that $V(C_1)\;{\cup}\;V(C_2)$ contains vertices of all partite sets of D. The problem of complementary cycles in 2-connected tournaments was completely solved by Reid [4] in 1985 and Z. Song [5] in 1993. They proved that every 2-connected tournament T on at least 8 vertices has complementary cycles of length t and ${\mid}V(T)\mid$ - t for all $3\;{\leq}\;t\;{\leq}\;{\mid}V(T)\mid/2$. Recently, Volkmann [8] proved that each regular multipartite tournament D of order ${\mid}V(D)\mid\;\geq\;8$ is cycle complementary. In this article, we analyze multipartite tournaments that are weakly cycle complementary. Especially, we will characterize all 3-connected c-partite tournaments with $c\;\geq\;3$ that are weakly cycle complementary.

• Journal of Korean Neurosurgical Society
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• 제59권1호
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• pp.58-61
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• 2016

Choroid plexus papillomas (CPPs) are relatively rare neuroectodermal tumors that develop from choroid plexus epithelial cells and are usually restricted to the ventricles. Extraventricular CPPs are very unusual and can be difficult to diagnose and treat. A 50-year-old male patient was admitted to our clinic complaining of headache and visual deterioration. Neurological examination found no abnormalities except decreased light perception and secondary optic atrophy in the left eye. Endocrine testing revealed normal levels of hormones produced by the pituitary and target glands. Magnetic resonance imaging of the brain revealed a huge regular-shaped lesion in the sellar-suprasellar region occupying the sella turcica and extending into the suprasellar cistern and planum sphenoidale. The lesion was completely excised by microsurgery via an ordinary left-sided pterional approach. Histopathology identified the lesion as a choroid plexus papilloma. Following the case report, literature on the origin, differential diagnosis, and treatment of this rare tumor is reviewed.

• 한국염색가공학회지
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• 제33권1호
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• pp.24-30
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• 2021

In this study, PET containing 3% silver ion-exchange zeolite was mixed with cotton in a ratio of 6:4 to prepare a spun yarn to evaluate the tensile strength, absorption speed, absorption rate, antibacterial property, and the efficiency of deodorization. As a result, the following conclusions were obtained. First, it can be confirmed that silver ion exchange zeolite is evenly distributed inside and on the surface of the antimicrobial PET-SF through SEM. It was found that the tensile strength between the CVC sample mixed with silver ion zeolite PET and cotton and the normal cotton 100% sample was slightly lower in the CVC sample. Although the absorption speed and water absorption rate were measured to find out the moisture characteristics, it was confirmed that there was no significant difference. The contact angle was slightly larger in the antimicrobial CVC sample, but the time it took for the moisture to completely penetrate into the knit fabric was 0.85 seconds. In addition, it was found that out of the total mixing ratio, 40% of antibacterial PET was spun with regular cotton to produce yarn, which had an excellent bacteria reduction rate of 99.9% and a deodorization efficiency of 85%.

• Molecules and Cells
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• 제41권5호
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• pp.413-422
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• 2018

Soybean transgenic plants with ectopically expressed AtABF3 were produced by Agrobacterium-mediated transformation and investigated the effects of AtABF3 expression on drought and salt tolerance. Stable Agrobacterium-mediated soybean transformation was carried based on the half-seed method (Paz et al. 2006). The integration of the transgene was confirmed from the genomic DNA of transformed soybean plants using PCR and the copy number of transgene was determined by Southern blotting using leaf samples from $T_2$ seedlings. In addition to genomic integration, the expression of the transgenes was analyzed by RT-PCR and most of the transgenic lines expressed the transgenes introduced. The chosen two transgenic lines (line #2 and #9) for further experiment showed the substantial drought stress tolerance by surviving even at the end of the 20-day of drought treatment. And the positive relationship between the levels of AtABF3 gene expression and drought-tolerance was confirmed by qRT-PCR and drought tolerance test. The stronger drought tolerance of transgenic lines seemed to be resulted from physiological changes. Transgenic lines #2 and #9 showed ion leakage at a significantly lower level (P < 0.01) than ${\underline{n}}on-{\underline{t}}ransgenic$ (NT) control. In addition, the chlorophyll contents of the leaves of transgenic lines were significantly higher (P < 0.01). The results indicated that their enhanced drought tolerance was due to the prevention of cell membrane damage and maintenance of chlorophyll content. Water loss by transpiration also slowly proceeded in transgenic plants. In microscopic observation, higher stomata closure was confirmed in transgenic lines. Especially, line #9 had 56% of completely closed stomata whereas only 16% were completely open. In subsequent salt tolerance test, the apparently enhanced salt tolerance of transgenic lines was measured in ion leakage rate and chlorophyll contents. Finally, the agronomic characteristics of ectopically expressed AtABF3 transgenic plants ($T_2$) compared to NT plants under regular watering (every 4 days) or low rate of watering condition (every 10 days) was investigated. When watered regularly, the plant height of drought-tolerant line (#9) was shorter than NT plants. However, under the drought condition, total seed weight of line #9 was significantly higher than in NT plants (P < 0.01). Moreover, the pods of NT plants showed severe withering, and most of the pods failed to set normal seeds. All the evidences in the study clearly suggested that overexpression of the AtABF3 gene conferred drought and salt tolerance in major crop soybean, especially under the growth condition of low watering.

• Journal of Korean Neurosurgical Society
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• 제60권6호
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• pp.667-675
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• 2017

Objective : Total resection without consecutive postoperative whole brain radiation therapy is indicated for patients with a single or two sites of brain metastasis, with close follow-up by serial magnetic resonance imaging (MRI). In this study, we explored the effectiveness, usefulness, and safety of this follow-up regimen. Methods : From January 2006 to December 2015, a total of 109 patients (76 males, 33 females) underwent tumor resection as the first treatment for brain metastases (97 patients with single metastases, 12 with two metastases). The mean age was 59.8 years (range 27-80). The location of the 121 tumors in the 109 patients was supratentorial (n=98) and in the cerebellum (n=23). The origin of the primary cancers was lung (n=45), breast (n=17), gastrointestinal tract (n=18), hepatobiliary system (n=8), kidney (n=7), others (n=11), and unknown origin (n=3). The 121 tumors were totally resected. Follow-up involved regular clinical and MRI assessments. Recurrence-free survival (RFS) and overall survival (OS) after tumor resection were analyzed by Kaplan-Meier methods based on clinical prognostic factors. Results : During the follow-up, MRI scans were done for 85 patients (78%) with 97 tumors. Fifty-six of the 97 tumors showed no recurrence without adjuvant local treatment, representing a numerical tumor recurrence-free rate of 57.7%. Mean and median RFS was 13.6 and 5.3 months, respectively. Kaplan-Meier analysis revealed the cerebellar location of the tumor as the only statistically significant prognostic factor related to RFS (p=0.020). Mean and median OS was 15.2 and 8.1 months, respectively. There were no significant prognostic factors related to OS. The survival rate at one year was 8.2% (9 of 109). Conclusion : With close and regular clinical and image follow-up, initial postoperative observation without prompt postoperative radiation therapy can be applied in patients of brain metastasi(e)s when both the tumor(s) are completely resected.

• 한국의상디자인학회지
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• 제7권2호
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• pp.25-37
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• 2005

This is a study on the origin of fashion imaging. First of all, 1 looked into the history of French fashion printmaking from late 16th century to early 19th century. Then studied the changes in the characteristics of context and form over the different periods and summarized each concept. At the same time, I looked into the process of fashion magazine evolving from fashion printmaking. In order to find out how fashion printmaking dealt with the characteristics of fashion media, 1 researched the commercial environment of fashion printmaking and reorganized the methodology of its media's role. Such analysis and results helped to reach a definition on how to regulate fashion printmaking. Fashion imaging was sparked by a small curiosity. As people began to be rage over new things, it came to introduce the fashion leaders of the public combined with the attributes of trend. At times when changes were so big that they were unpredictable, it itself became a fashion leader. Then a fashion creator emerges and it's function changes to that of a communication media. Moreover, the regular issuance of fashion printmaking implemented the concept of trend cycle and fashion imaging completely fulfilled the conditions of a communication media. The massive increase in the production of fashion printmaking and magazine contributed to the spread of fashion and the diffusion of printmaking lead to mutual complementation and synergy necessitated by fashion. Thus, the democratization of fashion and the commercialization of printmaking art occurred at the same time.

• Ocean and Polar Research
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• 제33권2호
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• pp.159-169
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• 2011

Antifreeze proteins (AFPs) have ice binding affinity, depress freezing temperature and inhibit ice recystallization which protect cellular membranes in polar organisms. Recent structural studies of antifreeze proteins have significantly expanded our understanding of the structure-function relationship and ice crystal growth inhibition. Although AFPs (Type I-IV AFP from fish, insect AFP and Plant AFP) have completely different fold and no sequence homology, they share a common feature of their surface area for ice binding property. The conserved ice-binding sites are relatively flat and hydrophobic. For example, Type I AFP has an amphipathic, single ${\alpha}$-helix and has regularly spaced Thr-Ala residues which make direct interaction with oxygen atoms of ice crystals. Unlike Type I AFP, Type II and III AFP are compact globular proteins that contain a flat ice-binding patch on the surface. Type II and Type III AFP show a remarkable structural similarity with the sugar binding lectin protein and C-terminal domain of sialic acid synthase, respectively. Type IV is assumed to form a four-helix bundle which has sequence similarity with apolipoprotein. The results of our modeling suggest an ice-binding induced structural change of Type IV AFP. Insect AFP has ${\beta}$-helical structure with a regular array of Thr-X-Thr motif. Threonine residues of each Thr-X-Thr motif fit well into the ice crystal lattice and provide a good surface-surface complementarity. This review focuses on the structural characteristics and details of the ice-binding mechanism of antifreeze proteins.

• 한국동물학회지
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• 제29권2호
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• pp.121-140
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• 1986

논우렁이(Cipangopaludina chinensis malleata (Reeve))의 精蟲形成 過程은 核과 細胞質의 變化로부터 시작한다. 核內의 染色質은 stacking 되기 시작하였으며 細胞質에서는 mitochondria의 모임과 軸絲의 出現이 되었다. 그런後에 細胞質은 突出되기 시작하였고, 核은 突部分으로 移動되었다. 精蟲形成過程中에 全 細胞質에서 나타나는 電子密度가 높은 物質들은 分解되거나 細胞間隙으로 exocytosis 되었다. 특히, mitochondria가 軸絲사이에 存在하며, 차츰 頭部쪽으로 移動되어지기 시작하였다. 그리고 exocytosis後에 電子密度가 높은 物質이 軸絲를 둘러싸기 시작했다. 이들 物質이 release되어 顆粒狀態로 微細小管이나 axonemal doublet 微細小管들을 通해서 각 部位로 移動되어졌다. 이러한 顆粒들은 glycogen을 함유하고 있으며 尾部의 바깥층을 이루고 있었다. 終局에 가서는 凝縮된 核은 螺旋形으로 變化하며 頸部는 cylinderical shape로 되고 中片의 mitochondria가 規則的인 lamellar屬으로 變化하여 완전히 成熟된 精蟲으로 되었다. 그러므로, 이러한 現象은 精蟲形成 過程의 特異한 過程을 나타낸다. 頭部의 染色質의 濃縮, 頭部의 螺旋狀 形態로 變化하는 것과 細胞性 物質이 mitochondria와 微細小管에 의하여 尾部의 각 部分으로 移動과 轉移되는 것이다.

• 한국산학기술학회논문지
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• 제17권3호
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• pp.292-297
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• 2016

본 논문은 다양한 형태의 방해물에 대한 정보를 알 수 없는 미지의 환경에서 자율이동 로봇의 항법에 관한 제안을 하고 있다. 로봇의 이동에 따른 주변의 정보는 로봇에 부착되어 있는 근접센서를 통하여 감지하고, 충돌을 피하고 목적지에 가능한 한 빨리 도착할 수 있는 경로로 유도하기 위하여 퍼지추론에 기반 한 항해방법을 개발하였다. 여기에서 방해물들은 정지되어 있고 정형화된 경우와 비정형화된 형태들이 고려되었으며 미로와 U형태의 계곡으로 구성된 예리한 방해물들을 특별히 포함하고 있다. 벽을 따라 이동하는 방법 또한 제안하고 있으며 모의실험을 통하여 제안하고 있는 방법이 이동로봇의 항법문제를 해결하는 효과적인 방법이 된다는 것을 증명하였다.

• 한국생산제조학회지
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• 제22권2호
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• pp.248-255
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• 2013

The objective of this study is to optimize the Metal Injection Molding(MIM) process with design of experiments(DOE) and numerical analysis. To derive the optimal process condition, experiment or numerical analysis was performed under various process conditions. To analyze the interaction among influential factors contributing to the temperature at flow front and response surface in MIM, both central point and axial point were added to the full factorial design with 2 levels and 5 factors and then their impacts on response variable in 43 experimental conditions were analyzed and the significance was evaluated. As a result, sprue, runner, and gate were completely filled in about 0.247 seconds after injection, the front part of the green body was filled in about 0.3344 seconds, the green body except gate, etc changed to almost solid state in about 3.29 seconds, the Packinging pressure was completed in about 6.29 seconds, and the green body inside and outside and sprue, etc became solid in 13.2 seconds. The impact of individual or reciprocal action of factors on the temperature at flow front was analyzed through regular probability, test statistics, main effect, and interaction effect. As a result, of a total of 31 combinations of factors, 9 unit factors and reciprocal actions were significant, and the screening was also possible. A proper regression equation was drawn with regression analysis and response surface design on the response variable of temperature at flow front, and the applicability could be verified.