• Information and Communications Magazine
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• v.30 no.3
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• pp.80-88
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• 2013

본 고에서는 차량 내에서 WiFi 기기를 사용하여 사용자들에게 인터넷 접속 서비스를 제공하는 구조인 모바일 핫스팟 (Mobile Hotspot)에 대한 연구 동향을 기술한다. 모바일 핫스팟과 관련된 연구 주제로는 1) 차량이 이동하더라도 인터넷 서비스를 끊임 없이 제공하는 이동성 관리 기술, 2) 사용자들의 향상된 서비스 품질을 보장하는 기술, 그리고 3) 모바일 핫스팟의 성능을 심도있게 분석하는 연구 등이 있다. 본 고에서는 이와 같은 연구 주제로 진행된 연구 결과를 정리하고 향후 연구 주제를 살펴본다.

• Journal of KIISE
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• v.45 no.2
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• pp.99-105
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• 2018

One of the spatial statistical analysis, hotspot analysis is one of easy method of see spatial patterns. It is based on the concept that "Adjacent ones are more relevant than those that are far away". However, in hotspot analysis is spatial adjacency must be considered, Therefore, distributed processing is not easy. In this paper, we proposed a distributed algorithm design for hotspot spatial analysis. Its performance was compared to standalone system and Hadoop, Spark based processing. As a result, it is compare to standalone system, Performance improvement rate of Hadoop at 625.89% and Spark at 870.14%. Furthermore, performance improvement rate is high at Spark processing than Hadoop at as more large data set.

• 한국데이터정보과학회:학술대회논문집
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• 2004.04a
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• pp.183-194
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• 2004

본 연구에서는 공간 검색 통계량(spatial scan statistics)과 에셜론 해석법을 이용한 범주형 자료분석을 다룬다. 이를 위해 우선, 에셜론 덴드로그램을 이용하여 주어진 분활표의 계층적 구조(hierarchical structure)를 결정하고서 이로부터 핫스팟(hotspot)의 후보를 검출한다. 다음으로 우도비(likelihood ratio)를 기초로 유의하게 높거나 낮게 나타나는 지역에 대한 공간 검색 통계량을 산출한다. 마지막으로, 이 통계량을 바탕으로 핫스팟을 검출한다.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.464-464
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• 2021

우리나라는 최근 도시지역의 광역화로 인해 시가화 지역이 지속적으로 증가하고 있으며, 이로 인해 증가한 불투수면적은 이수 및 치수 측면에서 다양한 문제를 야기하여 유역의 물순환 체계를 왜곡하고 있다. 더불어 하천의 건천화에 따른 하천 유지유량의 감소 및 공공수역으로 방출되는 오염물질의 증가는 하천의 다양한 환경적, 생태학적 문제를 야기하고 있다. 따라서 최근에는 유역 물순환 관리가 국가 물관리 정책의 핵심 전략으로 부각되고 있으며, 적절한 물순환 관리를 위해서는 물순환 건전성이 취약한 우선관리 유역을 도출하고, 해당 유역을 중심으로 보다 체계적이고 통합적인 유역관리 기술이 필요하다. 따라서 본 연구에서는 유역 물순환에 영향을 미치는 주요 요소들을 기후, 수문, 수질 및 사회·경제적 요인 측면으로 구분하고, Pressure-State-Response (PSR) framework를 적용하여 각 요소 별 주요 평가 지표들을 압력 (Pressure), 상태 (State) 및 반응(Reponse) 요인으로 분류하였다. 또한 전국 소권역 단위에 대하여 각 지표들을 분석하여 기후, 수문, 수질 및 사회·경제적요인 별 물순환 건강성 점수를 산정하였다. 한편, 지역 및 요인별 물순환 건강성 점수를 기반으로 핫스팟 분석 (Hot Spot Analysis)을 수행하여, 통계적으로 유의미한 패턴을 나타내는 지역을 중심으로 우선관리가 필요한 지역을 도출하였다. 본 연구에서 도출한 물순환 건강성 평가 요소별 점수 및 핫스팟 분석 결과는 향후 물순환 우선관리 지역 선정에 있어 기초자료로 활용될 수 있을 것으로 기대된다.

• Korean Journal of Clinical Laboratory Science
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• v.55 no.2
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• pp.93-104
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• 2023

This study aimed to identify new markers that cause lung adenocarcinoma by analyzing mutation hotspots for the top five genes with high mutation frequency in lung adenocarcinoma in Koreans by next generation sequencing (NGS) analysis. The association between TP53 mutation types and patterns with smoking, a major cause of lung cancer, was examined. The clinicopathological characteristics of lung adenocarcinoma patients with TP53 P72R SNPs were analyzed. In Korean lung adenocarcinoma cases, regardless of the smoking status, the TP53 P72R SNP was the most frequently occurring mutational hotspot, in which the nucleotide base was transversed from C to G, and the amino acid was substituted from proline to arginine at codon 72 of TP53. An analysis of the clinicopathological characteristics of lung adenocarcinoma cases with TP53 P72R SNP revealed no significant correlation with the patient's age, gender, smoking status, and tumor differentiation, but a significant correlation with low stage (P-value =0.026). This study confirmed an increase in TP53 rather than EGFR, which was reported as the most frequent mutations in lung adenocarcinoma in Koreans through NGS. Among them, TP53 P72R SNP is the most frequent regardless of smoking status.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.3
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• pp.221-230
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• 2016

To establish objective criteria for high pedestrian accident zones, we combined Getis-ord Gi* and Kernel Density Estimation to select high pedestrian accident zones for 54,208 pedestrian accidents in Seoul from 2009 to 2013. By applying Getis-ord Gi* and considering spatial patterns where pedestrian accident hot spots were clustered, this study identified high pedestrian accident zones. The research examined the microscopic distribution of accidents in high pedestrian accident zones, identified the critical hot spots through Kernel Density Estimation, and analyzed the inner distribution of hot spots by identifying the areas with high density levels.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.2A
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• pp.128-137
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• 2006

In this paper, we propose a wireless network discovery scheme which support effective device power management by employing battery efficient network scanning procedure. Multi-mode terminals need to discover other wireless systems, above all, to execute an inter-system handover in the environment of heterogeneous wireless networks. The existing methods introduced in some recent research reports have certain shortcomings, such as battery power consumption increased by frequent modem activation, or the multi-mode terminal's inability to promptly discover wireless system. We Propose a scheme in which multi-mode terminals more quickly and accurately discover other wireless systems than previous schemes, while consuming minimum power. It also proves that the scheme has better performance by comparing it with the existing schemes.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.2
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• pp.175-185
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• 2023

As drought risk increases due to climate change, various research works are underway around the world to respond to drought so as to minimize drought damage. In particular, in recent years, many studies are focused on analyzing regional patterns of drought in a comprehensive manner, however there is still insufficient to quantitatively identify drought-risk areas in a large river basin considering climate change in Korea. In this study, we calculated the Standardized Precipitation Index (SPI) and the Modified Standardized Precipitation Index (M_SPI) as representative meteorological drought index, and performed spatial autocorrelation analysis to identify the drought hotspot region under climate change scenarios of Representative Concentration Pathway (RCP) 4.5 and RCP 8.5. The SPI was calculated by estimating parameters for each observation station within the study area, whereas the M_SPI was calculated by estimating parameters for the entire study area. It is more reasonable to use the M_SPI for assessing meteorological drought from an overall perspective within the study area. When the M_SPI was used, long-term droughts showed drought hotspot areas clearly larger than short-term droughts. In addition, the drought hotspot area moved from the center of the Nakdong River basin to the Seomjin River basin over time. Especially, the moving patterns of the short-term/long-term drought were apparent under the RCP 4.5, whereas the moving patterns of the long-term drought were distinct under the RCP 8.5 scenarios.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.166-168
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• 2005

본 논문에서는, axa 출력 버퍼 스위치로 구성된 핫스팟이 발생된 상황 하에서 다단 연결 망(Multistage interconnection Network, MIN)의 성능 예측 모형을 제안하였다. 제안한 성능 예측 오형은 먼저 네트워크 내부 임의 스위치 입력 단에 유입되는 데이터 패킷이 스위치 내부에서 전송되는 유형을 확률적으로 분석하여 설계하였다. 성능분석 모형은 스위치에 장착된 버퍼의 개수와 무관하게 버퍼를 장착한 axa 스위치의 성능, 네트워크 정상상태 처리율(Normalized Throughput, NT)과 네트워크 지연시간(Network Delay)의 예측이 가능하고, 나아가서 이들로 구성진 모든 종류의 다단 연결망 성능 분석에 적용이 용이하다. 제안한 수학적 성능 분석 연구의 실효성 검증을 위하여 병행된 시뮬레이션 결과는 상호 미세한 오차 범위 내에서 모형의 예측 데이터와 일치하는 결과를 보여 분석 모형의 타당성을 입증하였다.

• Journal of KIISE:Information Networking
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• v.34 no.3
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• pp.193-202
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• 2007

In this paper, a performance evaluation model of the Multistage Interconnection Network(MIN) with the multiple-buffered crossbar switches under Hot-spot environment is proposed and examined. Buffered switch technique is well known to solve the data collision problem of the MIN. The proposed evaluation model is developed by investigating the transfer patterns of data packets in a switch. The performance of the multiple-buffered $a{\times}a$ crossbar switch is analyzed. Steady state probability concept is used to simplify the analyzing processes. Two important parameters of the network performance, throughput and delay, are then evaluated. To validate the proposed analysis model, the simulation is carried out on a Baseline network that uses the multiple buffered crossbar switches. Less than 2% differences between analysis and simulation results are observed. It is also shown that the network performance is significantly improved when the small number of buffer spaces is given. However, the throughput elevation is getting reduced and network delay becomes increasing as more buffer spaces are added in a switch.