• Journal of Technology Innovation
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• v.25 no.3
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• pp.25-50
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• 2017

Declining research competitiveness and inefficiency are constantly being raised in the National Assembly and the media for the Government-funded Research Institutes(GFRIs), which are highly dependent on government funding. These external stakeholders point to the workforce aging of the GFRIs as one of the main causes of inefficiency. They insist that the aging leads to an increase in labor costs, a discontinuity in research, a decrease in employment of new researchers, and a decrease in research competitiveness. However, the GFRIs argue that the aging is a natural phenomenon due to an increase in the age of recruitment, and even if there is an side effect, it is extremely small or even vice versa. It is interesting that there is no empirical study identifying the correlation between the workforce aging and the research performance of the GFRIs, despite the discussion. This study tracked and analyzed the changes of the research performance and the workforce for the five years from 2011 to 2015, and tried to demonstrate the correlation between the workforce aging and the research performance. As a result, we confirmed that there is an inverted U-type correlation between the aging and the papers, one of the research performance, and that the optimal age is 44.96 years. Also, we could not find any correlation between the aging and the patents.

• Journal of Veterinary Clinics
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• v.21 no.1
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• pp.45-48
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• 2004

A five months old, female Himalayan cat was referred to the Veterinary Medical Teaching Hospital at Konkuk University, because of suspecting peritoneopericardial diaphragmatic hernia (PPDH). After consecutive examination, the patient was diagnosed as PPDH and hepatic dysfunction. In spite of medical therapy for a month, the serum chemistry profiles for liver enzymes (aspartate transferase: 469 U/L, alanine transferase: above analysis, gamma-glutamyl transferase: above analysis) did not decrease to the normal range. In operation, some of liver was necrotized and was adhesive to diaphragm, these were gently dissected from thoracic structures, and resected. After debriding, the edges of the defect of diaphragm were closed with a simple continuous suture pattern. One month after operation, the cat had normal condition, recovery was uncomplicated, and the serum chemistry profiles for liver enzymes decrease to the normal range.

• Biomolecules & Therapeutics
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• v.8 no.2
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• pp.140-146
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• 2000

Recently, we reported that immunostimulation of primary rat cortical astrocyte caused stimulation of glucose deprivation induced apoptotic cell death. To enhance the understanding of the mechanism of the potentiated cell death of clucose-deprived astrocyte by immunostimulation, we investigated the effect of immunostimulation on the glucose deprivation induced cell death of rat C6 glioma cells. Co-treatment of C6 glioma cells with lipopolysaccharide (LPS, $1\;{\mu}\textrm{g}/ml$) and interferon ${\gamma}(IFN{\gamma},\;100U/ml)$ is serum free condition caused marked elevationo f nitric oxide production ($>50\;{\mu}M$). In this condition, glucose deprivation caused significant release of lactate dehdrogenase (LDH) from C6 glioma cells while control cells did not show LDH release. To investigate whether elevated level of nitric oxide is responsible for the enhanced LDH release in glucose-deprived condition, C6 glioma cells were treated with 3-morphorinosydnonimine (SIN-1) and it was observed that SIN-1 caused increase in LDH release from glucose-deprived C6 glioma cells. Treatment of C6 glioma cells with $25\;{\mu}M$ of pyrrolidinedithiocarbamate (PDTC) which inhibit Nuclear factor kB (NF-kB) activation, caused complete inhibition of nitric oxide production. Treatment of C6 glioma cells with NO synthase inhibitors, $N^{G}$-nitro-L-arginine (NNA) or L-$N{\omega}$-nitro-L-arginine methyl ester (L-NAME), caused inhibition of nitric oxide production and also glucose deprivation induced cell death of cytokine-stimulated C6 glioma cells. In addition, diaminohydroxypyrimidine (DAHP, 5 mM) which inhibits the synthesis of tetrahydrobiopterine (BH4), one of essential cofactors for iNOS activity, caused complete inhibition of NO production from immunostimulated C6 glioma cells. The results from the present study suggest that immunostimulation causes potentiation of glucose deprivation induced death of C6 glioma cells which is mediated at least in part by the increased production of nitric oxide. The vulnerability of immunostimulated C6 glioma cells to hypoglycemic insults may implicate that the elevated level of cytokines in various ischemic and neurodegenerative diseases may play a role in their pathogenesis.

• Health Policy and Management
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• v.6 no.1
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• pp.163-190
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• 1996

본 논문은 미국 농촌병원의 경영전략과 관련하여 몇가지 가설을 검증한 연구결과이다. 구체적으로 1987년부터 1991년 사이의 미국 농촌병원들의 기본적 경영전략 지향 형태와 변화 추세, 경영전략과 환경 및 병원특성과의 관계, 그리고 경영전략과 재정적 성과의 관계 등이 연구되었다. 본 연구의 자료수집은 미국 농촌지역의 모든 종교병원과 영리병원, 그리고 무작위 표본추출로 뽑힌 50%의 공공병원 및 기타 비영리 병원의 최고경영자를 대상으로 1989년에 우편설문조사를 통해 이루어졌으며 회수된 설문지 중 사용가능한 640개 병원 (응답율 43%)의 자료가 분석 이용되었다. 조사대상병원의 환경적 특성자료는 지역자원 파일(Area Resource File)에서 수집하였고, 병원특성 및 재정적 성과자료는 미국병원협회 연감(Annual Survey of Hospitals)에서 구하였다. 응답병원과 비응답병원간에 환경 및 병원특성에 유의한 차이는 없는 것으로 나타났다. 본 연구에서는 Miles와 Snow가 개발한 방어형(defender), 분석형(analyzer), 진보형(prospector), 반응형(reactor)의 네가지 경영전략지향 형태를 사용하여 분석하였다. 본 연구의 결과를 요약하면 다음과 같다. 1) 미국 농촌 병원들은 과거에는 방어형 및 분석형의 경영전략 지향을 보이다가 점차 반응형과 진보형으로 변화해 가고 있다. 2) 가장 뚜렷한 경영전략 지향의 변화추세는 방어형이 급격히 줄고 반응형이 크게 늘어나고 있다는 점이다. 이는 많은 병원들이 급격한 환경변화에 적응하기 위해 일관된 전략 지향보다 융통성 있고 탈력적인 경영전략을 선호하고 있음을 나타낸다. 3) 농촌병원들은 경영전략의 급격한 변화를 추구하지는 않을 것이라는 가설을 뒷받침할 근거는 없는 것으로 나타났다. 이는 급격한 의료환경의 변화로 인해 병원들이 다양한 경영전략의 변화를 모새하고 있는 것으로 볼 수 있다. 4) 대부분의 외부환경 및 병원특성은 병원의 전략지향의 선택에 큰 영향을 미치지 않는 것으로 나타났으나 인구 10,000명당 의사수, 병상규모, 위탁경영 여부, 병상점유율, 소유형태 등의 변수들이 경영전략 지향 형태에 따라 유의한 차이가 있는 것으로 나타났다. 5) 경영전략 지향이 상이한 병원들은 세부 실천전략에 있어서도 치이가 있을 것이라는 가설을 일부 전략에 있어서 사실인 것으로 나타났다. 즉 방어형 병원들은 진보형이나 반응형 병원들보다 내부관리전략, 다양화 전략, 의사유치전략, 직원복지전략 등에 있어서 소극적인 것으로 나타났다. 6) 비록 방어형 병원들이 다른 형태의 병원보다 낮은 재정적 성과를 보이고 있었지만 본 연구의 자료로는 경영전략지향과 재정적 성과간의 인과관계를 구명할 수 없었다. 또한 재정적성과에 따른 전략지향의 변화여부도 통계적으로 유의한 관계가 있지는 않은 것으로 나타났다. 이는 각각의 전략지향들이 환경에 따라 나름대로 장점을 가질 수 있으며 반드시 어느 한가지의 전략지향만이 최선은 아님을 시사해주고 있다. 7) 병원의 경영전략 변화는 환경의 변화와 더블어 그러한 변화에 적응할 수 있는 내부의 능력과도 관계가 있는 것으로 보인다. 이상의 연구결과에 따르면 미국의 농촌병원들은 급격한 환경변화에 적응하기 위하여 다수의 병원들이 환경 및 벼원특성에 관계없이 생존을 위한 전략적 노력을 기울이고 있음을 알 수 있다. 끝으로 이러한 연구결과는 최근 어려운 경영환경에 처한 한국의 농촌병원들도 합리적인 경영을 위해서는 병원이 처한 외부환경분석과 함께 내부의 능력에 적합한 경영전략의 방향을 설정하고 그에 따른 실천적 세부 경영전략을 수립해야만 한다는 것을 시사해 주고 있다.

• Education of Primary School Mathematics
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• v.14 no.1
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• pp.81-95
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• 2011

In order to raise people with mathematical power and positive attitude toward mathematics fit for the 21st century, individual students should be provided with equal learning opportunities according to their ability and level, and the need of such mathematics education is even stronger for underachievers. As textbooks were considered the optimal learning materials at each stage, this study purposed to examine changes in students' mathematical learning abilities and mathematical tendency brought by the activities of analyzing and reviewing the textbooks of the previous grades. The subjects of this study were 5 mathematics underachievers from 3 fifth grade classes at D Elementary School. They were sampled from those who were selected based on the results of diagnostic assessment and the records at the end of April and gave their consent to participation in this study. For the sampled children, their current state was surveyed first, and then the experimental classes were given twice a week and a total of 32 sessions. The children judged their mathematical abilities through reviewing the textbooks from the 1st grade to the 4th grade, and studied the textbook of each stage by themselves. After the self study, they had the textbook contents review activity that extracted 10 problems considered important per semester, and the textbook analysis activity that grouped units in each stage according to relevancy, identified similarities and differences, and examined hierarchy. From the results of this study was found that the mathematics underachiever teaching method using the textbooks of the previous grades gives mathematics underachievers confidence in their abilities, strengthens mathematical connection, and develops the habits of exploring key contents through self study.

• Journal of muscle and joint health
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• v.21 no.1
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• pp.1-10
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• 2014

Purpose: The purpose of the study was to identify the attributes of self-help groups, their antecedents and consequences relating to self-help groups. Methods: We used the Walker and Avant (2010) method using the key word "self-help groups" the Korea Education and Research Information Service (www.riss4u.net), Pubmed, CINAHL and ProQuest for articles on this topic published between January 2000 and March 2013 were searched. Ultimately, 64 domestic and 21 foreign papers were selected for in-depth analysis. Results: The attributes of self-help groups are as follows: 1) members share common experiences and are supportive of each other; 2) members set goals for individual change; 3) groups are self-monitoring; 4) groups learn problem-solving processes through voluntary and active participation; and 5) groups are small and meet regularly. The antecedents of self-help groups are as follows: 1) an intervention by an expert; 2) a diagnosis of their illness; 3) motivation to change individuals' state; and 4) educational desire. The consequences of self-help groups are the relief of symptoms, the improvement of physiological parameters and quality of life, the decrease in depression, stress, and anxiety, the improvement of illness-related knowledge and self-help activity, and a change in beliefs. Conclusion: Self-help groups can be used as an intervention strategy to help people with chronic illness manage their own problems.

• Food Science of Animal Resources
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• v.31 no.1
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• pp.47-53
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• 2011

Salmonella enterica serovar Typhimurium (ST) is one of the most common serovars isolated from humans and animals. It has been suggested that ST infections in Koreans are largely due to the consumption of contaminated pork and beef. To investigate the genotypes, phage types, and antimicrobial resistance patterns for ST isolates of different origins, a total of 70 ST strains, including 19 isolates from humans, 44 isolates from pigs, and 6 isolates from cattle, were analyzed using pulsedfield gel electrophoresis (PFGE), phage typing, and antimicrobial susceptibility tests. Forty-three distinct PFGE patterns were generated from 70 ST isolates, which were grouped into 14 PFGE groups (from A to N) at the level of 75% similarity. The most prevalent group was the A (A1-A17 subtypes) group, encompassing 54.5% (38/70) of ST isolates. ST isolates from pigs and cattle mostly belong to groups A and L, whereas ST isolates from humans mostly belong to groups F and C. Antimicrobial susceptibility tests using 11 antimicrobial agents showed that resistance to tetracycline (TE) (81.4%) was highly prevalent, followed by streptomycin (S) (64.3%) and nalidixic acid (NA) (31.4%) resistance. A total of seventeen antimicrobial resistance patterns were observed. Only 8.6% of isolates, including a reference strain, were susceptible to all antimicrobial agents tested. The most prevalent resistance pattern was TE-S (37.1%), which was seen in 66.6% of bovine, 40.8% of swine and 21.1% of human isolates. Three ST isolates from humans (15.9%) showed resistance to 7-8 antimicrobials. The most predominant phage type (PT) was U302 (64.3%), followed by DT170 (10.0%). PFGE types did not coincide with antimicrobial resistance patterns and phage types; therefore, the combination of those types allowed for further differentiation between tested ST isolates.

• Biomolecules & Therapeutics
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• v.15 no.3
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• pp.150-155
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• 2007

In the present study, we have tested the effect of dioleoyl phosphatidic acid (PA) on intracellular $Ca_{2+}$ concentration ($[Ca^{2+}]_{i}$) in two human colon cancer cell lines (HCT116 and HT29). PA and lysophosphatidic acid (LPA), a bioactive lysolipid, increased $[Ca^{2+}]_{i}$ in both HCT116 and HT29 cell lines. Increases of $[Ca^{2+}]_{i}$ by PA and LPA were more robust in HCT116 cells than in HT29 cells. A specific inhibitor of phospholipase C (U73122), however, was not inhibitory to the cell responses. Pertussis toxin, a specific inhibitor of $G_{i/o}$ type G proteins, however, had an inhibitory effect on the responses except for an LPA-induced one in HT29 cells. Ruthenium red, an inhibitor of the ryanodine receptor, was not inhibitory on the responses, however, 2-APB, a specific inhibitor of inositol 1,4,5-trisphosphate receptor, completely inhibited both lipid-induced $Ca^{2+}$ increases in both cell types. Furthermore, by using Ki16425 and VPC32183, two structurally dissimilar specific antagonists for $LPA_{1}/LPA_{3}$ receptors, an involvement of endogenous LPA receptors in the $Ca^{2+}$ responses was observed. Ki16425 completely inhibited the responses but the susceptibility to VPC32183 was different to PA and LPA in the two cell types. Expression levels of five LPA receptors in the HCT116 and HT29 cells were also assessed. Our data support the notion that PA could increase $[Ca^{2+}]_{i}$ in human colon cancer cells, probably via endogenous LPA receptors, G proteins and $IP_{3}$ receptors, thereby suggesting a role of PA as an intercellular lipid mediator.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.48-48
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• 2011

2010년 약 19.5 GWp 의 규모로 성장한 태양광 시장의 주요 소재는 실리콘을 이용한 태양전지이며, 고성능 및 고효율 태양전지 시장이 급성장 하였다. 이러한 고품질 태양전지에 사용되는 주요 원료인 9N 급 폴리실리콘은 2008년 4월 $265/kg 까지 상승하였으나, 점차 하향안정세에 있으며, 급속한 가격 경쟁을 통해 당분간 장기공급가가 50$/kg 이하로 하락할 것으로 전망된다. 이러한 실리콘 제조기술 중 가장 많이 사용되는 기술은 Trichloro-silane (TCS) 또는 Mono-silane (MS)를 사용하는 기상법인 일명 Siemens 공정이다. 이러한 기상법의 경우 12N 이상의 초고품질 실리콘 제조가 가능하나, 대규모의 설비투자(1억원/폴리실리콘 1톤)와 높은 에너지(120 kWh/kg)가 요구된다. 이에 최근 기상법이 아닌 야금학적인 정련법에 대한 기술이 개발되고 있으며, 이는 금속 실리콘을 슬래그 처리, 편석 분리, 응고 급랭, 전자빔, 플라즈마 등을 이용하여 정련하는 공정을 말한다. 야금학적 정련법은 순도 면에서 기상법에 비하여 낮은 단점이 있음에도 불구하고, 여러 장점들로 인해 활발히 연구되며 점차 실용화 되고 있는 매우 유용한 기술이다. 야금학적 정련법의 주요 장점은 기상법에 비해 약 25% 정도의 설비 투자비로 가능하고, 금속 실리콘을 직접 사용하며, 에너지 payback이 짧다. 또한, 산 및 염화실렌을 사용하지 않으므로 환경 문제를 적게 야기하고, 생산설비의 확장성도 매우 높다. 본 연구에서는 국내 규석광을 이용하여 일련의 정련 공정을 거쳐 고순도SG(Solar Grade)급 실리콘을 제조하고자 하였다. 실리콘 용융 환원로를 개발하고 순도를 높이기 위해 슬래그정련법을 이용하였으며, 생산된 3N 급의 금속 실리콘을 비기상법정련 방식인 일방향 응고와 플라즈마 정련 및 전자기유도 용해법을 이용하여 고순도의 실리콘을 제조하였다. 본 연구에서는 상업생산을 개시한 외국의 E사와 비교하여 산침출공정을 거치지 않으므로 실리콘회수율 및 환경부하 절감의 장점을 갖고 있으며 최종 순도 실리콘 6N 이상, 보론 함유량 0.2 ppm 이하를 달성하였으며, 기존 기상법 대비 약 20%의 전력 감소와 약 13%의 금속실리콘 원료 절감 효과가 있었다. 저가/고순도 SG급실리콘의 제조기술 개발은 향후 세계 태양광 시장에 대한 경쟁력을 확보하고, 시장 점유율 상승에 기여할 수 있으며, 산업 확대를 통한 주변 산업으로의 파급 효과가 매우 클 것으로 예상된다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.32 no.3
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• pp.233-244
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• 2014

Precise Point Positioning (PPP) is an increasingly recognized precisely the GPS/GNSS positioning technique. In order to improve the accuracy of PPP, the error sources in PPP measurements should be reduced as much as possible and the ambiguities should be correctly resolved. The correct ambiguity resolution requires a careful control of residual errors that are normally categorized into random and systematic errors. To understand effects from two categorized errors on the PPP ambiguity resolution, those two GPS datasets are simulated by generating in locations in South Korea (denoted as SUWN) and Hong Kong (PolyU). Both simulation cases are studied for each dataset; the first case is that all the satellites are affected by systematic and random errors, and the second case is that only a few satellites are affected. In the first case with random errors only, when the magnitude of random errors is increased, L1 ambiguities have a much higher chance to be incorrectly fixed. However, the size of ambiguity error is not exactly proportional to the magnitude of random error. Satellite geometry has more impacts on the L1 ambiguity resolution than the magnitude of random errors. In the first case when all the satellites have both random and systematic errors, the accuracy of fixed ambiguities is considerably affected by the systematic error. A pseudorange systematic error of 5 cm is the much more detrimental to ambiguity resolutions than carrier phase systematic error of 2 mm. In the $2^{nd}$ case when only a portion of satellites have systematic and random errors, the L1 ambiguity resolution in PPP can be still corrected. The number of allowable satellites varies from stations to stations, depending on the geometry of satellites. Through extensive simulation tests under different schemes, this paper sheds light on how the PPP ambiguity resolution (more precisely L1 ambiguity resolution) is affected by the characteristics of the residual errors in PPP observations. The numerical examples recall the PPP data analysts that how accurate the error correction models must achieve in order to get all the ambiguities resolved correctly.