• 대한수학회보
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• 제31권1호
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• pp.85-92
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• 1994

It is well known that there exist no closed minimal surfaces in a 3-dimensional Euclidean space R$^{3}$. Myers [4] generalized the result to the case of the higher dimension and proved that there are no closed minimal hypersurfaces in an open hemisphere. The complete and non-compact version concerning Myers' theorem is recently considered by Cheng [1] and the following theorem is proved.

• 응용통계연구
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• 제31권4호
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• pp.517-528
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• 2018

다변량 자료에서 특이점을 검출하고, 검출된 특이점을 시각화와 연결한 R 스크립트를 제공한다. 개발된 R 스크립트는 특이점을 검출하는 방법으로서 1) Robust Mahalanobis distance, 2) High Dimensional data, 3) Density-based approach 방법을 이용하였다. 특이점을 연결하면서 데이터 구조를 파악하기 위한 시각화 방법으로는 1) multidimensional scaling (MDS)와 minimal spanning tree (MST)를 K-means 군집분석과 연결하여 표시하는 방법, 2) MDS를 fviz cluster와 연결하는 방법, 3) principal component analysis (PCA)를 fviz cluster와 연결한 방법을 이용하였다. 사례분석의 예로서는 Major League Baseball (MLB) 자료에서 류현진이 적극적으로 활동하던 2013년, 2014년 투수자료를 이용하였다. 개발된 R 스트립트는 "http://www.knou.ac.kr/~sskim/ddpoutlier.html (R 스크립트와 R 패키지도 다운로드 받을 수 있다. 실행방법도 설명되어 있다.)"에서 다운받으면 된다.

• Journal of Periodontal and Implant Science
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• 제34권3호
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• pp.499-508
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• 2004

Regeneration of Periodontium with PRP does not only improve regeneration rate and density of bone but have a possibility to estimate faster healing process for soft tissue. And also, autogenous bone and xenogenic bone graft are effective on regeneration of periodontium. The purpose of this study is to evaluate the effectiveness of autogenous bone and xenogenic bone $(BBP^{(R)})$ grafts with the PRP technique on regeneration of periodontium. 52 Generally healthy Pt. who had pocket depth 5mm at any of 6 surfaces of the teeth were in the study at Dept. of Perio. in Dankook Dental Hospital. Open Flap was treated for 18 infra-bony pockets as control group, autogenous bone with PRP was inserted for 25 infrabony pockets as first test group, and $(BBP^{(R)})$ with PRP was inserted for 22 infrabony pockets as 2nd test group. Then evaluation was made after 3 and 6 months 1. There were significant differences between average probing pocket depth and clinical attachment level of 3, 6 months and minimal and maximal attachment level after 6 months each other. 2. There were significant differences in average probing pocket depth of control group and 2nd experimental group between 1 and 6 months. For clinical attachment level and minimal and maximal proving attachment level, there was a significant difference after 6 month of surgery. 3. There was no significant difference between two test groups for average probing depth, clinical attachment level, and minimal and maximal probing attachment level. As the result, PRP with bone graft could be very effective for regeneration of periodontium and there was no difference between xenogenic bone and autogenous bone.

• 소성∙가공
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• 제22권4호
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• pp.183-188
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• 2013

Scroll compressors are widely used in air conditioning systems and in automobiles due to their low pressure loss, minimal vibrations, and light-weight. Open-die forging with back pressure is used to forge the rotating scroll, and it requires special care since the forging die can be severely damaged at the fixed end of the spiral cavity similar to a fracture of a cantilever beam. To overcome the inevitable weakness of the forging die due to such damage, an innovative design is necessary. In this study, structural analysis using the finite element method was conducted to determine the reason for the fracture of the forging die. A novel design to avoid stress concentrations and vertical deflection, causing serious damage to the die, is suggested.

• 한국미생물·생명공학회지
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• 제23권2호
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• pp.178-186
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• 1995

Streptomyces albus wild type ATCC 21838 produced salinomycin, polyether antibiotic. To clone genes related salinomycin production, a genomic library was screened using actI as a DNA hybridization probe. pWHM 210 was isolated, which contained an approximately 24 kb of insert DNA. A 3.8 kb region in the 24 kb insert DNA was hybridized to actI and the nucleotide sequence of this region was determinied. Two open reading frames found in the same direction were homologous to genes for $\beta$-keto acyl synthase/acyl transferase and chain length determining factor in type II PKS (polyketide synthase). The genes were components of minimal type II PKS genes, highly conserved and showed the strong simiarity to other type II PKS genes known today.

• 생물정신의학
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• 제2권2호
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• pp.281-286
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• 1995

Objects : Manic phase of bipolar disorder is treated with a combination of mood stabilizer and antipsychotic drug, especially in the acute phase. Such combined treatment is often required for the clinical management of manic symptoms until therapeutic effects of mood stabilizer become evident. The present study was the first open trial to evaluate the efficacy of risperidone, and safety of the combination of mood stabilizer and risperidone in the treatment of acute manic patients. Method : This study was performed as an open clinical study. The subjects of this study were 42 patients who had been admitted with first manifestations or acute exacerbations of illness were selected, using DSM-III-R criteria for bipolar disorder, manic episode. Patients were rated using the the Brief Psychiatric Rating Scale (BPRS), Clinical Global Impression (CGI), Extrapyramidal Symptom Rating Scale(ESRS). Other adverse events were assessed by a symptom checklist and by observation by medical personnel. Vital signs were monitored in a standard way and electrocardiography, routine laboratory analysis were performed. Results : Thirty patients(67%) completed the 12-week trial period. The CGI showed a good therapeutic effect with a minimal incidence or severity of side effects. The majority of patients showed a continuos reduction in their BPRS scores. The extrapyramidal symptoms assessed on ESRS generally showed mild to moderate degree. laboratory porameters showed no significant changes during the course of treatment. Conclusion : The results of the study showed a good efficacy of the risperidone in manic patients and further controlled studies are warranted.

• Archives of Plastic Surgery
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• 제46권4호
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• pp.350-358
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• 2019

Background Carpal tunnel syndrome (CTS) is the most common peripheral entrapment neuropathy with a high morbidity and healthcare-related costs. Currently there is no consensus about the best treatment option. The purpose of this prospective cohort study conducted at a single institution was to evaluate the clinical outcomes and patient satisfaction following a mini-open carpal tunnel release for idiopathic CTS. Methods A total of 72 patients (53 female and 19 male patients; mean age, $57.8{\pm}15.3$ years; range, 24-94 years) had a mini-open carpal tunnel release performed by a single senior surgeon between June 2015 and June 2016. The patients were evaluated preoperatively, and at 3 and 12 months post-intervention. At every follow-up, the Boston Carpal Tunnel Syndrome Questionnaire (BCTSQ) and visual analogue scale (VAS) scores for pain and satisfaction were completed. Digital sensibility (using Semmes-Weinstein monofilaments) was assessed and pinch and grip strengths were measured. Results Statistically significant and clinically relevant improvement was found in terms of digital sensibility, grip and pinch strength (except for 2-point pinch), BCTSQ scores and pain scores. The complication rate was minimal, and no major complications occurred. Two patients experienced recurrence. The availability of follow-up records (including patient-reported outcomes, BCTSQ and VAS scores, and the complication rate) at 1-year post-intervention varied between 69% and 74% (50-53 patients) depending on which parameter was assessed. Patient satisfaction was high (mean, $80.9{\pm}26.0$; range, 0-100). Conclusions This study demonstrates that mini-incision carpal tunnel release is clinically effective in the short and long term.

• Journal of Periodontal and Implant Science
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• 제31권4호
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• pp.737-747
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• 2001

Regeneration of Periodontium with PRP does not only improve regeneration rate and density of bone but have a possibility to estimate faster healing process for soft tissue. And also, synthetic bone and xenogenic bone graft are effective on regeneration of periodontium. The purpose of this study is to evaluate the effectiveness of synthetic bone ($Biogran^{(R)}$) and xenogenic bone ($BBP^{(R)}$) grafts with the PRP technique on regeneration of periodontium. 52 Generally healthy Pt. who had pocket depth 5mm at any of 6 surfaces of the teeth were in the study at Dept. of Perio. in Dankook Dental Hospital. Open Flap was treated for 18 infra-bony pockets as control group, $Biogran^{(R)}$ with PRP was inserted for 25 infrabony pockets as first test group, and $BBP^{(R)}$ with PRP was inserted for 22 infrabony pockets as 2nd test group. Then evaluation was made after 3 and 6 months 1. 6 months after surgery, each difference of average probing pocket depth was $2.61{\pm}0.23$ for control, $3.40{\pm}0.30$ for 1st test, and $3.45{\pm}0.37$ for 2nd test group. 2. 6 months after surgery, each difference of clinical probing attachment level was $1.39{\pm}0.12$ for control, $2.88{\pm}0,24$ for 1st, and $2.86{\pm}0,27$ for 2nd test group. 3. 6 months after surgery, each difference of Maximal probing attachment level was $1.11{\pm}0.16$ for control, $3.28{\pm}0.30$ for 1st, and $3.27{\pm}0.35$ for 2nd test group. 4. There were significant differences for clinical change of each three group which were between average probing pocket depth and clinical attachment level of 3,6 months and minimal and maximal attachment level after 6 months 5. There were significant differences for average probing pocket depth which were only at control group and 2nd test group between 1 and 6months. For clinical attachment level and minimal and maximal proving attachment level, there was a significant difference after 6month of surgery. 6. There was no significant difference between two test groups for average probing depth, clinical attachment level, and minima1 and maximal probing attachment level. As the result, PRP with bone graft is very effective for regeneration of periodontium and there is no difference between xenogenic bone and synthetic bone.

• East Asian mathematical journal
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• 제33권5호
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• pp.571-585
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• 2017

Let M be a connected n-dimensional submanifold of a Euclidean space $E^{n+k}$ equipped with the induced metric and ${\Delta}$ its Laplacian. If the position vector x of M is decomposed as a sum of three vectors $x=x_1+x_2+x_0$ where two vectors $x_1$ and $x_2$ are non-constant eigen vectors of the Laplacian, i.e., ${\Delta}x_i={\lambda}_ix_i$, i = 1, 2 (${\lambda}_i{\in}R$) and $x_0$ is a constant vector, then, M is called a 2-type submanifold. In this paper we showed that a 2-type surface M in $E^3$ satisfies ${\langle}{\Delta}x,x-x_0{\rangle}=c$ for a constant c, where ${\langle},{\rangle}$ is the usual inner product in $E^3$, then M is an open part of a circular cylinder. Also we showed that if a quadric hypersurface M in a Euclidean space satisfies ${\langle}{\Delta}x,x{\rangle}=c$ for a constant c, then it is one of a minimal quadric hypersurface, a genaralized cone, a hypersphere, and a spherical cylinder.

• Journal of Microbiology and Biotechnology
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• 제5권2호
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• pp.74-79
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• 1995

Sequence analysis of a DNA region encompassing the site of hybridization to actl, the gene for type II minimal polyketide synthase (PKS) for actinorhodin biosynthesis, from Streptomyces ablus revealed three more complete open reading frames additional to the already found two genes, plausibly encoding ${\beta}-ketoacyl$ synthase/acyl transferase (KS/AT) and chain length determining factor (ClF). The open reading frames (ORFs) were named salA, salD, and salE, from the upstream. In the homology analysis of the deduced amino acid sequences, SalA resembles the Streptomyces glaucescens Tcml, decaketide cyclase, SalD resembles acyl carrier protein in type II PKS, and SalE resembles the Actlll ketoreductase, The whole 4.4 kb of DNA sequence obeys the same conservation pattern as other type II PKSs. Therefore, we suggest that the 4.4 kb DNA from Streptomyces albus encompasses genes encoding enzymes for polyketide biogenesis in the organism and its organization is type II. The exsitence of SaIA, an analogue of the aromatic cyclase, revealed a relatedness of the 4.4 kb DNA with the aromatic PKS.