• 농촌계획
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• 제20권3호
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• pp.67-74
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• 2014

The purpose of this study is to estimate regional economic effects of spatial diffusion of wildfire using Cobb-Douglas production function of agriculture and forestry. The analysis is applied to Gangwon and Gyeongbuk provinces where are the most damaged of wildfire in Korea. The damaged areas are derived from multiplied by the occurrence probability of wildfire and diffusion areas of wildfire for micro-spatial unit level with ArcGIS techniques. The models of wildfire provides that the spatial diffusion of wildfire increases with the rising of highest temperature and average wind speed. Through the production function, value added of Agriculture and Forest sectors get damaged where the Cos-converted slope aspect of mountains are toward the South. The production model provides reductions of regional value added by increasing damaged areas of wildfire. It reveals that the most damaged region is Andong city in Gyeongbuk province, where value added loss is 1.25 billion Won, which is about 0.72% of total value added in agriculture and forestry of the city. As a view of policy makers, it needs to be considered to establish prevention policies against wildfires because regional economic losses from wildfire are depending on geographical conditions and performances of the major industry related to wildfire's diffusion such as agriculture or tourism sector according to the result of analysis.

• 반도체디스플레이기술학회지
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• 제3권3호
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• pp.19-21
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• 2004

This paper presents a 3-dimensional diffusion simulation with adaptive solution strategy. The developed diffusion simulator VLSIDIF-3 was designed to re-refine areas. Refine scheme was calculated by the difference of doping concentration between any of two nodes. Each element is greater than tolerance and redo diffusion process until error is tolerable. Numerical experiment in low doping diffusion problem showed that this adaptive solution strategy is very efficient in both memory and time, and expected this scheme would be more powerful in complex diffusion model.

• 한국반도체및디스플레이장비학회:학술대회논문집
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• 한국반도체및디스플레이장비학회 2004년도 춘계학술대회 발표 논문집
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• pp.55-58
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• 2004

This paper presents a 3-dimensional diffusion simulation with adaptive solution strategy. The developed diffusion simulator VLSIDIF-3 was designed to re-refine areas where difference of doping concentration between any of two nodes of each element is greater than tolerance and redo diffusion process until error is tolerable. Numerical experiment in low doping diffusion problem showed that this adaptive solution strategy is very efficient in both memory and time, and expected this scheme would be more powerful in complex diffusion model.

• 산업기술연구
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• 제27권B호
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• pp.53-58
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• 2007

In this paper, we propose a design of the implementation for a search and rescue system for mountain climbers and evaluate the performance of the system. Search and rescues of people in emergency situations in mountain areas have been difficult due to lack of information about their location. In the proposed design, several small and commonly-available RF-based sensors, some amount of storage and processing devices are used. Infestations offer geographically intermittent coverage at high speeds. The proposed mountain climber tracking system use the directed diffusion scheme combined with infostation system. We also analyze the performance of the proposed system with NS-2 simulation package. From the performance analysis results, we expect that the proposed system will be very useful to early detect climbers' locations in emergency situations in Korea mountain areas.

• 기술혁신연구
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• 제11권2호
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• pp.71-89
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• 2003

Since technological innovation, adoption, and diffusion is a fundamental engine for a company's competitiveness and in turn a nation's industrial development, diffusion of technological innovation has been one of popular research themes to many researchers and scholars for decades. Especially, in today's knowledge-based economy, the IT technology became a fundamental infrastructure for a nation and thus their impact on a nation's economy has grown to be tremendous. This paper investigates the patterns of technological diffusion of 16 telecommunications services. Firstly, we identify the optimal diffusion model which represents the 15 IT innovation best in terms of goodness-of-fit. Secondly, based on the best model identified we cluster the 16 IT innovations according to their diffusion characteristics such as penetration rate and diffusion speed. Lastly, we categorize the innovations in terms of technology (voice-based innovation and data-based innovation) and demand (household-use and business-use) attributes, and compare their diffusion patterns and found some meaningful difference in diffusion patterns. We hope the result helpful to corporate managers as well as policy makers in relevant areas.

• Journal of Korean Neurosurgical Society
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• 제64권3호
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• pp.418-426
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• 2021

Objective : A role of diffusion-weighted imaging (DWI) in the diagnosis of cerebral venous thrombosis (CVT) is not well-understood. This study evaluates the effectiveness of DWI in the diagnosis of CVT. Methods : Literature search was conducted in electronic databases for the identification of studies which reported the outcomes of patients subjected to DWI for CVT diagnosis. Random-effects meta-analyses were performed to achieve overall estimates of important diagnostic efficiency indices including hyperintense signal rate, the sensitivity and specificity of DWI in diagnosing CVT, and the apparent diffusion coefficient (ADC) of DWI signal areas and surrounding tissue. Results : Nineteen studies (443 patients with 856 CVTs; age 40 years [95% confidence interval (CI), 33 to 43]; 28% males [95% CI, 18 to 38]; symptom onset to DWI time 4.6 days [95% CI, 2.3 to 6.9]) were included. Hyperintense signals on DWI were detected in 40% (95% CI, 26 to 55) of the cases. The sensitivity of DWI for detecting CVT was 22% (95% CI, 11 to 34) but specificity was 98% (95% CI, 95 to 100). ADC values were quite heterogenous in DWI signal areas. However, generally the ADC values were lower in DWI signal areas than in surrounding normal areas (mean difference-0.33×10-3 ㎟/s [95% CI, -0.44 to -0.23]; p<0.00001). Conclusion : DWI has a low sensitivity in detecting CVT and thus has a high risk of missing many CVT cases. However, because of its high specificity, it may have supporting and exploratory roles in CVT diagnosis.

• 한국경제지리학회지
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• 제1권1호
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• pp.137-149
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• 1998

교통망의 확충계획이 있거나 확충작업이 이루어지고 있는 지역에서는 그로 인한 직접적인 접근성 증가와 더불어 교통망의 개선에 따른 접근성 증가의 주변지역으로의 파급효과를 정확히 신출할 수 있다면 지역 전체의 접근성 공간구조를 파악할 수 있게 되고, 지가와 토지이용의 변화를 정확히 예측할 수 있게 되어 교통을 포함한 각종 지역계획과정에서 효율적이고 합리적인 대안선정을 위한 기준을 제공할 수 있을 것이다. 기존의 그래프이론에 기반을 둔 접근성 측정모형에 의해 산출되는 결정점의 접근성 증가가 주변지역으로 파급되는 효과를 정확히 산출할 수 있는 이론적 모형의 개발을 시도하였다. 특히 결정점을 중심으로 주변지역으로 거리가 멀어지면서 변화하는 지하철 접근도의 영향력을 측정하기 위한 이론적 모형을 제시하고 있다. 지하철역의 접근도가 주변지역으로 확산되는 정도는 주변지역에서 그 지하철역을 이용하는 정도와 일치한다고 보고 주변지역의 지하철역 이용밀도를 기반으로 수학적 함수식을 도출하였다. 이러한 연구는 궁극적으로는 최근 지리적 분석기법으로 각광을 받고 있는 GIS기법에 접목시켜 지표현상의 설명에 핵심이 되는 접근성의 공간적 보간에 대한 이론적 근거를 마련한다는 의미를 지닌다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.592-599
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• 2005

Renewable energy technology development has been carrying out in 11 different areas so far. Many technologies are being applied to the required areas according to its own characteristics. Before launching the development, these technologies have been evaluated by their commercial effect and contribution to energy supply. In this paper, the impact factors enhancing the distribution of renewable energy were developed to select appropriate diffusion regulations for each technology area. In addition, AHP methodology was introduced to investigate priorities of the regulations along with weights of impact factors.

• 신재생에너지
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• 제1권2호
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• pp.79-90
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• 2005

New & renewable energy technology development has been carrying out in 11 different areas so far. Many technologies are being applied to the required areas according to its own characteristics. Before launching the development, these technologies have been evaluated by their commercial effect and contribution to energy supply. In this paper, the impact factors enhancing the distribution of renewable energy were developed to select appropriate diffusion regulations for each technology area. In addition, AHP methodology was introduced to investigate priorities of the regulations along with weights of impact factors.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권1호
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• pp.46-54
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• 2002

Plasma Display Panel (PDP) is required to be both the determination of white point of each gray level and the inverse gamma correction since no-balanced RGB cell and linear property of PDP, respectively. However, these two methods cause degradation of grey level representation and undesirable false contour in the dark areas on PDP. In this paper, we implemented real time image processor of the proposed error diffusion algorithm and unsharp masking operation to protect the blurring image caused by the error diffusion. Experimental results showed drastic improvements of gray level representation and reduction of undesirable false contour.