• Asian Pacific Journal of Cancer Prevention
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• v.15 no.8
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• pp.3435-3441
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• 2014

Background: Axillary lymph node status at diagnosis remains the strongest predictor of long-term survival in breast cancer. Patients with more than ten axillary lymph nodes at diagnosis have a poor long-term survival. In this single institutional study, we set out to evaluate the prognosis of this high-risk group in the era of multimodality therapy. Materials and Methods: In this retrospective study, we looked at all breast cancer patients with greater than ten axillary lymph nodes diagnosed at Mount Sinai Medical Center (MSMC) from January 1st 1990 to December 31st 2007 (n=161). In the univariate analysis, descriptive frequencies, median survival, and 5- and 10-year survival rates were estimated for common prognostic factors. A multivariate prognostic analysis for time-to-event data, using the extended Cox regression model was carried out. Results: With a median and mean follow-up of 70 and 89.9 months, respectively, the overall median survival was estimated to be 99 months. The five-year disease-free survival (DFS) was 59.3% and the ten-year DFS was 37.9%, whereas the five- and ten-year overall survival (OS) was 66.6% and 43.9%, respectively. Multivariate analysis revealed a significant improvement in DFS among black patients compared to whites (p=0.05), improved DFS and OS among young patients (ages 21-45) compared to elderly patients (age greater than 70) (p=0.00176, p=0.0034, respectively), and improved DFS and OS among patients whose tumors were ER positive (p=0.049, p=0.0034). Conclusions: In this single institution study of patients with greater than 10 positive axillary nodes, black patients had a significantly improved DFS compared with white patients. Young age and ER tumor positivity was associated with improved outcomes. Using multivariate analysis, there were no other variables associated with statistically significant improvements in DFS or OS including date of diagnosis. Further work is needed to improve breast cancer survival in this subgroup of patients.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.2
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• pp.307-318
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• 2015

In this study, the efficiency of two-dimensional inundation analysis using road network was demonstrated in order to reduce the simulation time of numerical model in urban area. For this objective, three simulation conditions were set up: Case 1 considered only inundation within road zone, while Case 2 and 3 considered inundation within road and building zone together. Accordingly, Case 1 used grids generated based on road network, while Case 2 and 3 used uniform and non-uniform grids for whole study area, respectively. Three simulation conditions were applied to Samsung drainage where flood damage occurred due to storm event on Sep. 21, 2010. The efficiency of suggested method in this study was verified by comparison the accuracy and simulation time of Case 1 and those of Case 2 and 3. The results presented that the simulation time was fast in the order of Case 1, 2 and 3, and the fit of inundation area between each case was more than 85% within road zone. Additionally, inundation area of building zone estimated from inundation rating index gave a similar agreement under each case. As a result, it is helpful for study on real-time inundation forecast warning to use a proposed method based on road network and inundation rating index for building zone.

• The korean journal of orthodontics
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• v.35 no.5 s.112
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• pp.331-340
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• 2005

Angulation and inclination of clinical crown is important for diagnosing, treatment planning and developing convenient orthodontic attachments. The aim of the study was to establish normative data with higher reliability on the angulation and inclination of clinical crown of Koreans with normal occlusion This study employed the dental casts of 307 (male. 187: female. 120) adult normal occlusion samples. The angulation and inclination of clinical crown were measured by set-up model checker In order to ensure reliability, intra- and inter-rater error were evaluated 3 times The resultant data obtained had excellent reliability however when compared with the previous data as well as with gender difference, clinically significant interpretation was impossible because the whithin-dataset normal variation was High which was common pattern of angulation and inclination measuring data of previous research The result of this biometric study seemed 4o suggest more substantive design of the multivariate. high-dimensional interpretation methodology of these normal variation is required if more compatible orthodontic appliance could be developed.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.2
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• pp.41-54
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• 2017

The purpose of this study is to find out how the support system of the government and the local governments for enhancing the success rate of the startup firms affected the performance of the enterprises according to the behavior characteristics of the founders. It is divided entrepreneurial support system into entrepreneurial policy support such as entrepreneurial education, mentoring and consulting, and funding of startup support such as policy fund and R & D fund, distinguished the behavior of founder into behaviors for discovery of entrepreneurial opportunities and behaviors for exploiting entrepreneurial opportunities. In order to analyze whether it affects the corporate management performance, a research model was created based on the previous research and hypotheses were set up, and the hypotheses were verified based on this questionnaire. The results of this study are as follows: First, it is found that the support for entrepreneurial policy has a positive effect on the behavior characteristics of entrepreneur. Second, it is found that the startup support such as policy fund affects the behavioral characteristics for finding the opportunity of the founder, but it does not affect the behavioral characteristics for the opportunity exploit. Third, it was found that the behavior characteristics of entrepreneur founding opportunity and exploition of entrepreneurial opportunity influenced the performance of the company. According to the this study, the following conclusion were obtained, First, it is necessary to apply different policies according to the stage of growth of startup companies. Second, startup companies grow through the stages of development of new technologies and ideas, commercialization, and marketing, at each stage, entrepreneur must overcome the so-called Death Valley, which requires funding.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.5
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• pp.471-476
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• 1985

In order to set up a predictive model for effective spat collection of Pacific oyster, Crassostrea gigas, the survival rate and time required at each developmental stage of drifting larvae were surveyed during the period from June 13 to October 16 in 1984 at the main oyster farming area, Hansan Bay, the southern part of Korea. The advent of D-shape larvae ca. $72{\times}61{\mu}m$ long had two peaks in that area : July 16 and September 20. Umbo-shape larvae ca. $189{\times}217{\mu}m$ and full grown larvae co. $303{\times}308{\mu}m$ long also showed two peaks: July 21 and September 25 for the former, and July 28 and September 30 for the latter. About five days were required for D-shape larvae to develop to umbo-shape larvae. The instantaneous death rate was 0.24 and the daily survival rate 0.78 with a mean survival rate of $29.38\%$, at this intermorphological stage. The turnover time of umbo to full grown larvae varied from five to seven days with a instantaneous death rate of 0.15, daily survival rate of 0.86 and mean survival rate of $38.54\%$. Ten to twelve days were required for each group of the D-shape larvae to reach a full grown stage, and their mean survival rate was $11.32\%$ during this developmental period.

• International Journal of Highway Engineering
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• v.20 no.1
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• pp.35-45
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• 2018

PURPOSES : This study examines the performance changes of road networks according to the strength of a disaster, and proposes a method for estimating the quantitative resilience according to the road-network performance changes and damage scale. This study also selected high-influence road sections, according to disasters targeting the road network, and aimed to analyze their hazard resilience from the network aspect through a scenario analysis of the damage recovery after a disaster occurred. METHODS : The analysis was conducted targeting Sejong City in South Korea. The disaster situation was set up using the TransCAD and VISSIM traffic-simulation software. First, the study analyzed how road-network damage changed the user's travel pattern and travel time, and how it affected the complete network. Secondly, the functional aspects of the road networks were analyzed using quantitative resilience. Finally, based on the road-network performance change and resilience, priority-management road sections were selected. RESULTS : According to the analysis results, when a road section has relatively low connectivity and low traffic, its effect on the complete network is insignificant. Moreover, certain road sections with relatively high importance can suffer a performance loss from major damage, for e.g., sections where bridges, tunnels, or underground roads are located, roads where no bypasses exist or they exist far from the concerned road, including entrances and exits to suburban areas. Relatively important roads have the potential to significantly degrade the network performance when a disaster occurs. Because of the high risk of delays or isolation, they may lead to secondary damage. Thus, it is necessary to manage the roads to maintain their performance. CONCLUSIONS : As a baseline study to establish measures for traffic prevention, this study considered the performance of a road network, selected high-influence road sections within the road network, and analyzed the quantitative resilience of the road network according to scenarios. The road users' passage-pattern changes were analyzed through simulation analysis using the User Equilibrium model. Based on the analysis results, the resilience in each scenario was examined and compared. Sections where a road's performance loss had a significant influence on the network were targeted. The study results were judged to become basic research data for establishing response plans to restore the original functions and performance of the destroyed and damage road networks, and for selecting maintenance priorities.

• Journal of the Korean Society for Nondestructive Testing
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• v.20 no.2
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• pp.138-149
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• 2000

Various modeling techniques for ultrasonic wave propagation and scattering problems in finite solid media are presented. Elastodynamic boundary value problems in inhomogeneous multi-layered plate-like structures are set up for modal analysis of guided wave propagation and numerically solved to obtain dispersion curves which show propagation characteristics of guided waves. As a powerful modeling tool to overcome such numerical difficulties in wave scattering problems as the geometrical complexity and mode conversion, the Boundary Element Method(BEM) is introduced and is combined with the normal mode expansion technique to develop the hybrid BEM, an efficient technique for modeling multi mode conversion of guided wave scattering problems. Time dependent wave forms are obtained through the inverse Fourier transformation of the numerical solutions in the frequency domain. 3D BEM program development is underway to model more practical ultrasonic wave signals. Some encouraging numerical results have recently been obtained in comparison with the analytical solutions for wave propagation in a bar subjected to time harmonic longitudinal excitation. It is expected that the presented modeling techniques for elastic wave propagation and scattering can be applied to establish quantitative nondestructive evaluation techniques in various ways.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.2
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• pp.95-105
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• 2001

A series of experiment is carried out to determine the holding power of the existing anchors used in the stationary gear in the coast of the South sea. The experiment apparatus is made of the pulling machine, the load cell, the personal computer and three water tanks the bottom of which are mud, sand and m & s respectively. The result obtained are as follows : 1. On the tension and holding power of the existing anchors, B-type of the stock anchor with two fluke shows the greatest and gets smaller on order of A-type one with a fluke. The holding power of the anchors shows the greatest in the mud and gets smaller in order of m & s, sand. And, the holding power depending upon the length of anchor rope increase as the length does up to the 4 times of depth. 2. On the holding power per fluke area of the existing anchors in case of ration of length of anchor rope to depth is 2, 3 and 4, A-type anchor shows about 310-320 kg/m supper(2), 470-480 kg/m supper(2), 590-640 kg/m supper(2) respectively, B-type one 260-265 kg/m supper(2), 390-450 kg/m supper(2), 630-700 kg/m supper(2) respectively, and C-type one 70-100 kg/m supper(2), 150-180 kg/m supper(2), 210-270 kg/m supper(2) respectively. The holding power per fluke area of the anchors increase as the length of anchor rope does. 3. On the coefficient of holding power of the existing anchors, A-type anchor shows the greatest and gets smaller in the order of B-type one, C-type one.

• Korean Journal of Remote Sensing
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• v.31 no.5
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• pp.461-471
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• 2015

In this study, we generated orthoimages and Digital Elevation Model (DEM) from Unmanned Aerial Vehicle (UAV) to confirm the accuracy of possibility of geospatial information system generation, then compared the DEM with the topographic height values measured from Real Time Kinematic-GPS (RTK-GPS). The DEMs were generated from aerial triangulation method using fixed-wing UAV and rotary-wing UAV, and DEM based on the waterline method also generated. For the accurate generation of mosaic images and DEM, the distorted images occurred by interior and exterior orientation were corrected using camera calibration. In addition, we set up the 30 Ground Control Points (GPCs) in order to correct of the UAVs position error. Therefore, the mosaic images and DEM were obtained with geometric error less than 30 cm. The height of generated DEMs by UAVs were compared with the levelled elevation by RTK-GPS. The value of R-square is closely 1. From this study, we could confirm that accurate DEM of the tidal flat can be generated using UAVs and these detailed spatial information about tidal flat will be widely used for tidal flat management.

• Journal of the Korean association of regional geographers
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• v.2 no.1
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• pp.87-114
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• 1996

This paper is the second part of a research which aims to look into the regional development process and the quality of life of Youngnam area. and to suggest a prospect and tasks for the future development of the region. All cities and regions including Youngnam area seem to be involved in a rapidly changing process of conditions for development, because of a recent economic and political transformation in the national and global scale. It can be thus said that, taking such a process into consideration seriously, each city or region needs to establish a long-term prospect and goal, and to set up and practicize its development plan. From this point of view, this paper reconsiders the changing process of conditions for development of Youngnam region, and suggests an alternative development plan. At the first, the changing conditions of regional development are investigated in economic, political, social, cultural and environmental aspects. Secondly, some actual planning practices in this regions are examined and their problems are pointed out. Thirdly, an alternative model for regional development is suggested and development tasks in each aspects are discussed in relation to each other. Finally some regional development strategies are provided in the spatial as well as the sectoral dimision. As a results of this research, it is argued that the development of Youngnam region should pursue both an improvement of socio-cultural and ecological institutions for ensuring humane life of dwellers within the region, and a enforcement of economic and political self-sufficiency in an organic relation between regions and to the whole society. This kind of argument can be applied to every city or region. But it would more significant for Youngnam region, because this region, which once experienced a rapid economic growth but now is fallen into a serious economic stagnation, tends to contrive material plans to redevelop regional economy, while ignoring social plans to improve quality of life.