• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.5
• /
• pp.3007-3013
• /
• 2014

The objectives of this study was to evaluate the validity of 3D digital models made from blue LED dental scanner. Twenty same cases of stone models and 3d digital models were manufactured for this study. Intercanine distance, intermolar distance, two dental arch lengths(right, left) and two diagonal of dental arch lengths(right, left) were measured for evaluation of validity. The nonparametric Wilcoxon rank sum test was used for statistical analysis (${\alpha}$=0.05). Although stone models showed larger than digital models in all measured distances(p<0.05), none exceeded the clinically acceptable range.

• Journal of Korean Neurosurgical Society
• /
• v.30 no.2
• /
• pp.137-143
• /
• 2001

Objective : Telomerase, a ribonucleoprotein adds telomere repeats to the ends of telomeres to compensate for the progressive loss. A favorable prognosis associated with low or no telomerase activity in some tumors, and cells transfected with antisense human telomerase lost telomeric repeats and die. We studied about the relationship between telomerase activity and apoptosis in the human brain tumors. Material and Methods : Between July 1998 and December 1999, 62 patients with brain tumors underwent surgery and their surgical specimens were obtained. Telomerase activity was investigated by telomeric repeats amplification protocol(TRAP) assay. Apoptosis was also evaluated by DNA fragmentation analysis. Differences and correlation in data were analyzed using Mann-Whitney test and Wilcoxon-signed rank test. Results : Expression rate of telomerase activity and apoptosis were 80% and 30% in malignant gliomas, 33% and 0% in low grade gliomas, 63% and 38% in meningiomas, 67% and 33% in pituitary adenomas, 33% and 33% in metastatic tumors, 67% and 17% in acoustic neurinomas, 100% and 100% in pineoblastomas, 100% and 0% in the hemangioblastoma, respectively. There was no significant difference of telomerase activity and apoptosis between histological types. But a significant difference was noted in the expression of telomerase activity between malignant gliomas and low grade gliomas(p = 0.022). Brain tumors with telomerase activity expressed the lower rate of apoptosis. A significant correlation was also found between telomerase activity and absence of apoptosis in the human brain tumors(p = 0.005). Conclusions : Our data suggests that telomerase may protect from apoptosis of the human brain tumors and also may play an important role in the biological malignancy of the gliomas.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.53 no.3
• /
• pp.99-106
• /
• 2016

In this paper, we will discuss about correction method of missing data on noisy observation matrix and uncertainty analysis for the potential noise. In situations without missing data in an observation matrix, this solution is known to be accurately induced by SVD (Singular Value Decomposition). However, usually the several entries of observation matrix have not been observed and other entries have been perturbed by the influence of noise. In this case, it is difficult to find the solution as well as cause the 3D reconstruction error. Therefore, in order to minimize the 3D reconstruction error, above all things, it is necessary to correct reliably the missing data under noise distribution and to give a quantitative evaluation for the corrected results. This paper focuses on a method for correcting missing data using geometrical properties between 2D projected object and 3D reconstructed shape and for estimating a noise level of the observation matrix using ranks of SVD in order to quantitatively evaluate the performance of the correction algorithm.

• Journal of Pathology and Translational Medicine
• /
• v.52 no.6
• /
• pp.369-377
• /
• 2018

Background: Chemokine receptor CXC chemokine receptor type 4 (CXCR4) and its ligand CXC motif chemokine 12 (CXCL12; stromal cell-derived factor-1) are implicated in tumor growth, metastasis, and tumor cell-microenvironment interaction. A number of studies have reported that increased CXCR4 expression is associated with worse prognosis in triple-negative breast cancer (TNBC), but its prognostic significance has not been studied in TNBC patients treated with adjuvant chemotherapy. Methods: Two hundred eighty-three TNBC patients who received adjuvant chemotherapy were retrospectively analyzed. Tissue microarray was constructed from formalin-fixed, paraffin-embedded tumor tissue and immunohistochemistry for CXCR4 and CXCL12 was performed. Expression of each marker was compared with clinicopathologic characteristics and outcome. Results: High cytoplasmic CXCR4 expression was associated with younger age (p=.008), higher histologic grade (p=.007) and lower pathologic stage (p=.045), while high CXCL12 expression was related to larger tumor size (p=.045), positive lymph node metastasis (p=.005), and higher pathologic stage (p=.017). The patients with high cytoplasmic CXCR4 experienced lower distant recurrence (p=.006) and better recurrence-free survival (RFS) (log-rank p=.020) after adjuvant chemotherapy. Cytoplasmic CXCR4 expression remained an independent factor of distant recurrence (p=.019) and RFS (p=.038) after multivariate analysis. Conclusions: High cytoplasmic CXCR4 expression was associated with lower distant recurrence and better RFS in TNBC patients treated with adjuvant chemotherapy. This is the first study to correlate high CXCR4 expression to better TNBC prognosis, and the underlying mechanism needs to be elucidated in further studies.

• Review of Culture and Economy
• /
• v.20 no.2
• /
• pp.3-18
• /
• 2017

The purpose of this study is to analyze changes in work autonomy of content industry workers using Korea Working Conditions Survey(2010, 2014) and difference-differences estimation method. The results find that there was no significant change in the work autonomy (work order, work method, work speed) of the content industry worker in In the overall sample. On the other hand, analyzing the sample of 30 or more employee establishment size shows that work autonomy of the content industry worker is greatly reduced. Also, work autonomy is high when the rank or capability is high, whereas work autonomy decreases when the establishment size is large. This study implies that the content industry workers have shown quantitatively the reduction of work autonomy. It also suggests that compensation and management systems are needed to enhance the competitiveness of the content industry.

• The Korean Journal of Food And Nutrition
• /
• v.32 no.5
• /
• pp.434-441
• /
• 2019

In this study, we analyzed the nutritional composition properties of soybeans and the organic acids, amino acids and volatile flavor compounds of fermented soybean products. We used five soybean cultivars including Pyeongwon, Jinpung, Saedanbaek, Saeolkong and Cheonga for this experiment. Physicochemical analysis of soybeans, showed that the cured protein and fat contents were 35.12~45.12 and 14.26~20.14%, respectively. The rank order of major organic acids was lactic acid > acetic acid > fumaric acid, with Saedanbaek being the highest. Total amino acid content of the samples was 358.12~657.28 mg/100 g, and glutamic acid, alanine, cysteine, valine, leucine, histidine and arginine were the major amino acids. We identified a total of 34 volatile aroma-compounds, including 7 alcohols, 7 acids, 7 ketones, 5 phenols, 2 esters, 1 furan, 4 pyrazines, and 1 miscellaneous compounds. As a result of this, could be applied to determine the suitability of cultivars and the quality for the process of the fermented soybean products.

• Korean Security Journal
• /
• no.56
• /
• pp.55-81
• /
• 2018

The purpose of this study is to find significant activities in human resource management (HRM) to solve growing-pains caused by the rapid external growth in private security business. To this end, we applied the HRM factors suggested by the National Job Capability Standard (NCS) to the private security and investigated the relative importance using the Analytic Hierarchy Process (AHP). The results were as follows. First, the importance of 4 HRM criteria in the private security was ranked in order of recruitment, operation, benefit, and retirement. Particularly, the relative importance of recruitment reached 63.8%. Second, the composite importance was calculated by dividing the 4 HRM criteria into 14 capability sub-criteria and 46 capability alternatives. As a result, personnel planning and hiring at the recruitment turned out as the areas that needed the most improvement. In addition, the operating and planning of education involved in the highest rank, 8th and 10th respectively. Based on these results, we suggested critical HRM factors for developing the private security business as well as proposed research directions and methods for further studies.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2018.05a
• /
• pp.419-419
• /
• 2018

기후변화로 인한 홍수피해의 빈도와 규모가 증가함에 따라 미래 홍수취약성은 갈수록 증가할 것으로 전망된다. 이를 대비하기 위해서는 지역별 기후변화를 고려한 홍수취약성 평가를 통해 적절한 적응 정책을 수립하여야 한다. 본 연구에서는 지역별 홍수취약성을 평가하기 위해 홍수취약성지수(Flood Vulnerability Index, FVI)를 새롭게 선정하였다. FVI는 3가지 구성요소의 결합으로 산정되며, 피해의 원인이 되는 압력지수(Pressure Index), 물리적 피해 현황을 나타내는 현상지수(State Index), 대응할 수 있는 능력인 대책지수(Response Index)의 함수로 나타낸다. 압력지수는 기후, 유역, 사회특성에 따라 세부지표를 구분하였고, 현상지수는 홍수피해 비율, 대책지수는 기술 및 사회적 특성을 기준으로 하였다. 따라서, 압력지수 및 현상지수가 클수록 홍수피해에 취약함을 나타내고, 대책지수가 클수록 취약성이 저감되게 된다. 연구 대상 지역은 최근 집중호우로 인해 많은 홍수피해가 발생한 금강유역을 선정하였고, 과거 홍수 피해액 자료를 사용하여 선정된 지수의 적용성을 검토하였다. 또한, 기후변화를 고려하기 위해 27개의 GCMs (Global Climate Models) 중 홍수를 가장 잘 설명하는 5개의 대표시나리오와 2개의 배출시나리오(RCP4.5, RCP8.5)를 사용하였으며, 과거(2010년대) 및 2030년대, 2050년대, 2080년대의 홍수취약성지수를 산정하여 결과를 분석하였다. Spearmans's rank correlation coefficient를 사용하여 과거 10년간 실제 홍수 피해액의 평균값과 FVI를 비교한 결과 선정된 지수가 홍수피해를 적절히 설명하는 것으로 나타났다. 대표시나리오를 사용한 미래 홍수취약성 분석 결과, 용담댐 유역에서 홍수취약성이 증가하는 것으로 나타났으며 지역별 상대적 취약성전망 결과는 대부분 과거와 비슷하였다.

• Korea journal of population studies
• /
• v.3 no.1
• /
• pp.62-77
• /
• 1979

The purpose of this study is to explain the increasing trend of the aged population and its demographic characteristics. This study is based on the data for the aged population above 65 years old published by the Bureau of Statistics, Economic Planning Board. The increasing trend of the aged population has been analyzed and projected from 1955 to the year 2000. Some demographic charicteristics of the aged population including marital status, educational status and status of economic activities have also been analyzed in order to identify the problems associated with aging of population in Korea. The study offers the following conclusion. 1. The aged population index, the proportion of aged population to total population was 3.6 in 1975 and projected to be 6.6 in 2000. There has been steady increase of the aged population is reflected in changes of population structure. The proportional change of the aged population index was 100.0 in 1955, 109.0 in 1975 and 200.0 in 2000 respectively. 2. As for marital status of the aged population 77.6 per cent of male were married while 24.3 per cent of female were married in 1975. 22 per cent of male were widowed while it spouses died declined remarkable the mortality rate declined. 3. As the educational status of the aged, 77 per cent never attended school and 18 per cent attended from a primary school. This is very low and the number of educated men is higher than that of educated women. The rank ordering of schooling is city, Eub and Myeon in that aged. 4. The dependency ratio of the aged population was 5.9 in 1955, 6.1 in 1975 and will be 9.8 in 2000. It is gradually increasing as indicated above 20 per cent of aged population was economically active of these, they are employed in the following occupations as listed in order of the magnitude of the aged population employed. The employment status of the aged workers shows that a greater number of persons are self-employed than workers for another employer. In particular, temporary employees comprise 56.0 per cent of those employed.

• Safety and Health at Work
• /
• v.12 no.4
• /
• pp.439-444
• /
• 2021

Background: In a previous study, we estimated exposure prevalence and the number of workers exposed to carcinogens by industry in Korea. The present study aimed to evaluate the optimal exposure intensity indicators of airborne lead exposure by comparing to blood lead measurements for the future development of the carcinogen exposure intensity database. Methods: Data concerning airborne lead measurements and blood lead levels were collected from nationwide occupational exposure databases, compiled between 2015 and 2016. Summary statistics, including the arithmetic mean (AM), geometric mean (GM), and 95th percentile level (X95) were calculated by industry both for airborne lead and blood lead measurements. Since many measurements were below the limits of detection (LODs), the simple replacement with half of the LOD and maximum likelihood estimation (MLE) methods were used for statistical analysis. For examining the optimal exposure indicator of airborne lead exposure, blood lead levels were used as reference data for subsequent rank correlation analyses. Results: A total of 19,637 airborne lead measurements and 32,848 blood lead measurements were used. In general, simple replacement showed a higher correlation than MLE. The results showed that AM and X95 using simple replacement could be used as optimal exposure intensity indicators, while X95 showed better correlations than AM in industries with 20 or more measurements. Conclusion: Our results showed that AM or X95 could be potential candidates for exposure intensity indicators in the Korean carcinogen exposure database. Especially, X95 is an optimal indicator where there are enough measurements to compute X95 values.