• Toxicological Research
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• 제21권2호
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• pp.135-140
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• 2005

Although the pathogenesis of cerebral cavernous malformation (CCM) is unknown, a familial predisposition has been recognized, with up to $55\%$ of patients having an affected relatives. Genetic linkage studies have recently mapped a gene causing CCM to a segment of the long arm of chromosome 7 (7q). We report herein a genetic linkage analysis conducted on a Korean three generation family with CCM. It's first report in Korean family. A Korean family in which one member had undergone surgery for ubtracerebrak hematoma (ICH) and confirmed the CCM, was evaluated. They were examined clinically (n=18) and by magnetic resonance (MR) imaging (n=10). Polymorphic markers (D7S1813, D7S1789) spanning the CCM1 locus on 7q were genotyped by the polymerase chain reaction and analysis of linkage was performed in this family (n=17). Six had multiple lesions on brain MR image, one of them being symptomatic, and five were asymptomatic. Seven remaining members were asymptomatic and refused MR image study. One had died of ICH from presumed CCM. Analysis of the pedigree was consistent with an autosomal dominant pattern of inheritance. All affected patients were linked to CCM1. Linkage to CCM1 can account for inheritance of CCM in this family. They had some striking features with a low clinical penetrance and the presence of multiple lesions. These findings have implications for genetic testing of this disorder and represent an important step toward identification of the gene responsible for the pathogenesis of this disease.

• Korean Journal of Mathematics
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• 제31권1호
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• pp.63-73
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• 2023

In this paper, we determine all repdigits, which are difference of two Pell and Pell-Lucas numbers. It is shown that the largest repdigit which is difference of two Pell numbers is 99 = 169 - 70 = P₇ - P₆ and the largest repdigit which is difference of two Pell-Lucas numbers is 444 = 478 - 34 = Q₇ - Q₄.

• 한국콘텐츠학회논문지
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• 제19권11호
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• pp.92-101
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• 2019

본 연구는 음식점에 직접 고용되지 않은 직원이 제공하는 음식배달대행서비스 행태에 관한 대학생들의 주관적인 의견과 인식의 구조를 유형별로 도출하기 위해 Q-방법을 사용하였다. 이를 위해 설문지를 작성하여 P샘플을 선정하고 분류작업을 거치는 Q-sort를 PC QUANL프로그램을 이용하여 Q요인 분석을 실시하였다. 분석 결과 총 3가지의 유형으로 분류되었다. 제 1유형(N= 7): 효율 추구형, 제 2유형(N= 19): 편익 추구형,〕제3유형〔(N= 6): 가성비 추구형으로 각 각의 유형별로 다른 특징에 기인하여 요인을 명명하였다. 각 유형별 특징은 제 1유형: 소비자와 외식업소 모두에게 효율적인 측면을 인식하는 유형, 제 2유형; 신속, 편리, 유익함의 편익을 제공받는 측면을 인식하는 유형, 제3유형; 인건비 절약에는 기여 하지만 소비자에게 부담가중의 초기 시장에서 가격과 품질 측면을 인식하는 유형으로 나타났다. 분류된 3가지 유형에 따른 음식배달대행서비스 사업의 문제점을 도출하여 발전 방향과 개선방안에 대하여 전략적 시사점을 제공하고자 한다.

• 해양환경안전학회지
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• 제25권1호
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• pp.130-137
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• 2019

원심 해수냉각 펌프를 분석하기 위하여 다른 운전 유량에 대한 캐비테이션 거동을 조사하였다. 3D 2상 해석은 ANSYS-CFX 상용코드로 수행되었다. 해석에는 $k-{\varepsilon}$ 난류와 Rayleigh-Plesset cavitation 모델이 사용되었다. 수치 예측에 기초하여 세 가지 토출 유량값에 대하여 헤드 드롭 특성곡선이 작성되었다. 더 높은 유량에서 임펠러는 버블 캐비테이션에 보다 취약하다. 0.7Q, Q 및 1.3Q(Q: 설계 유량)에서 작동하는 펌프의 3 % 헤드 드롭 위치는 각각 NPSHa 1.21 m, 1.83 m 및 3.45 m에 해당한다. 증기 기포의 볼륨이 예측되고 캐비테이션의 위치는 임펠러 내에서 발생하는 캐비티를 시각화하여 예상하였다. 또한, 압력계수와 날개 부하 분포가 구체적으로 제시되어 캐비테이션이 펌프 운전에 미치는 해로운 영향을 나타냈다. 또한, 압력계수 분포와 날개부하 차트가 구체적으로 제시되어, 펌프 운전에 캐비테이션이 미치는 해로운 영향을 나타냈다.

• 한국가스학회지
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• 제25권6호
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• pp.14-21
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• 2021

-162℃ 초저온 상태의 LNG를 저장하는 저장탱크의 내조는 균열과 같은 결함에 대한 구조 건전성 평가가 필요하다. 전통적인 파괴역학 관점에서는 응력확대계수 K, J-적분 그리고 CTOD를 이용한 단일 매개변수 평가가 주로 수행되어왔다. 그러나 실제 구조에서 발생되는 균열선단은 구조물의 크기, 시편형상 그리고 인장과 굽힘과 같은 하중의 형태에 따라 구속효과의 차이로 인한 영향이 발생하게 된다. 단일 매개변수 파괴역학을 보완하기 위해 다양한 시도가 있었고, 대표적으로 Q-응력법이 있다. 본 논문에서는 비선형 탄성영역의 균열선단 응력장 평가에 적합한 J적분에 Q응력을 유도하여 2 매개변수 접근법을 사용하고자 한다. SENB 시편의 균열비 0.1~0.7 그리고 광폭시편 균열비 0.2~0.6에 시편 균열선단의 응력을 J-Q 평가법을 이용하여 구속효과를 정량적으로 평가 하였다.

• Korean Journal of Mathematics
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• 제32권1호
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• pp.43-57
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• 2024

Given a domain X and a collection H of functions h : X → {0, 1}, the Vapnik-Chervonenkis (VC) dimension of H measures its complexity in an appropriate sense. In particular, the fundamental theorem of statistical learning says that a hypothesis class with finite VC-dimension is PAC learnable. Recent work by Fitzpatrick, Wyman, the fourth and seventh named authors studied the VC-dimension of a natural family of functions ℋ'²_t(E) : 𝔽²_q → {0, 1}, corresponding to indicator functions of circles centered at points in a subset E ⊆ 𝔽²_q. They showed that when |E| is large enough, the VC-dimension of ℋ'²_t(E) is the same as in the case that E = 𝔽²_q. We study a related hypothesis class, ℋ^d_t(E), corresponding to intersections of spheres in 𝔽^d_q, and ask how large E ⊆ 𝔽^d_q needs to be to ensure the maximum possible VC-dimension. We resolve this problem in all dimensions, proving that whenever |E| ≥ C_dq^d-1/(d-1) for d ≥ 3, the VC-dimension of ℋ^d_t(E) is as large as possible. We get a slightly stronger result if d = 3: this result holds as long as |E| ≥ C_3q^7/3. Furthermore, when d = 2 the result holds when |E| ≥ C_2q^7/4.

• 대한소아치과학회지
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• 제42권4호
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• pp.312-318
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• 2015

본 연구의 목적은 치과분야에서 줄기세포 공급원으로써 과잉치의 활용 가능성을 알아보고자 Real Time Quantitative Reverse Transcription Polymerase Chain Reaction (Real Time qRT-PCR)법을 이용하여 발치된 과잉치 치수 유래 줄기세포 (supernumerary dental pulp stem cells, sDPSCs)로부터 상아모세포로의 분화여부를 관찰해 보는 것이었다. 이를 위해 상아모세포의 대표적인 발현인자로 알려진 alkaline phosphatase (ALP), osteocalcin (OC), osteonectin (ON), dentin matrix acidic phosphoprotein 1 (DMP-1) 그리고 dentin sialophosphoprotein(DSPP)의 발현을 분화제 처리 후 0일, 8일 그리고 14일째에 각각 Real Time qRT-PCR 법을 통해 상대적인 mRNA의 발현 양을 비교하여 변화 양상을 알아보았다. 또한 Alizarin-red solution 의 염색을 통해 sDPSCs가 분화제 처리 7일, 14일, 21일 그리고 28일째에 석회화 결절을 형성하는 정도를 시각적으로 확인해 보았다. Real Time qRT-PCR 결과 분화제 처리 8일째에 가장 높은 발현 양을 보이다가 14일째에 감소하는 추세를 나타내었으며, Alizarin-red solution 염색 결과는 7일째부터 흐리게 나타나다가 14일째에는 배지 전반에 걸쳐 진하게 염색되는 소견을 보였다. 따라서, sDPSCs를 이용한 연구에서 Real Time qRT-PCR법을 위한 분화제의 처리 기간은 8일 정도가 적절하며, Alizarin-red solution 염색은 14일이 적당한 것으로 사료된다.

• 한국환경과학회지
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• 제28권9호
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• pp.785-795
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• 2019

In order to analyze the sensitivity of carbon dioxide flux by soil temperature in the grassplot, carbon dioxide flux and soil temperature were observed 24 times from March, 2010 to March, 2011 at nine sites in the grassplot. The average of $CO_2$ in the grassplot is $2.2{\sim}36.7^{\circ}C$, the highest in August, the lowest in January, and the average of carbon dioxide flux is $12{\sim}1479mgCO_2{\cdot}m^{-2}{\cdot}hr^{-1}$, and the carbon dioxide emission from the grassplot to the atmosphere was 10 times higher in summer than in winter. The temperature response coefficient estimated by the exponential function of carbon dioxide flux according to soil temperature was ranged from 0.1065 to 0.1274, and the increase tendency of $CO_2$ flux with soil temperature was linear at $0{\sim}20^{\circ}C$ and exponential at $20{\sim}40^{\circ}C$. The $Q_{10}$ values for each of nine observation sites on the grassplot was in the range of 2.901 ~ 3.575, and the $Q_{10}$ value using the total data observed in the lawn was estimated to be 3.374. In the homogeneous grassplot area, the average of $Q_{10}$ values by observation point and the $Q_{10}$ value by the total data were estimated similarly.

• Investigative Magnetic Resonance Imaging
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• 제22권3호
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• pp.158-167
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• 2018

Purpose: To investigate the surgical, perfusion, and molecular characteristics of glioblastomas which influence long-term survival after treatment, and to explore the association between MR perfusion parameters and the presence of MGMT methylation and 1p/19q deletions. Materials and Methods: This retrospective study was approved by our institutional review board. A total 43 patients were included, all with pathologic diagnosis of glioblastoma with known MGMT methylation and 1p/19q deletion statuses. We divided these patients into long-term (${\geq}60\;months$, n = 7) and short-term (< 60 months, n = 36) survivors, then compared surgical extent, molecular status, and rCBV parameters between the two groups using Fisher's exact test or Mann-Whitney test. The rCBV parameters were analyzed according to the presence of MGMT methylation and 1p/19q deletions. We investigated the relationship between the mean rCBV and overall survival using linear correlation. Multivariable linear regression was performed in order to find the variables related to overall survival. Results: Long-term survivors (100% [7 of 7]) demonstrated a greater percentage of gross total or near total resection than short-term survivors (54.5% [18 of 33]). A higher prevalence of 1p/19q deletions was also noted among the long-term survivors (42.9% [3 of 7]) than the short-term survivors (0.0% [0 of 36]). The rCBV parameters did not differ between the long-term and short-term survivors. The rCBV values were marginally lower in patients with MGMT methylation and 1p/19q deletions. Despite no correlation found between overall survival and rCBV in the whole group, the short-term survivor group showed negative correlation ($R^2=0.181$, P = 0.025). Multivariable linear regression revealed that surgical extent and 1p/19q deletions, but not rCBV values, were associated with prolonged overall survival. Conclusion: While preoperative rCBV and 1p/19q deletion status are related to each other, only surgical extent and the presence of 1p/19q deletion in GBM patients may predict long-term survival.

• 한국식생활문화학회지
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• 제27권6호
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• pp.636-645
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• 2012

The purpose of this study is to investigate factors influencing dietary satisfaction, and their perceived importance and performance, in North Korean refugees according to age. Questionnaires were completed by 220 North Korean refugees and data was analyzed with SPSS software. From our study we determined that fresh food, clean dishes, and proper vegetable oil are of high importance but considered poorly performed. 'Taste' and 'comfort' were factors with low importance but considered well-performed. The IPA technique proved that 8 items including Q4, Q5, Q6, Q7, Q8, Q9, Q11, Q13 were in 'Doing great, keep it up' and no items that got high importance and low performance were in 'Focus here'. North Korean refugees like Korean food more than Chinese, Japanese, and Western food. They specifically want to learn how to cook Korean casseroles, soups, and side dishes(e.g. Myeolchibokkum, Kongjorim). The North Korean refugees who resided in South Korea under a year have difficulties in understanding menus and Western table manners.