• Journal of Korean Society for Atmospheric Environment
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• 제14권E호
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• pp.41-58
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• 1998

In this study, a wide range of volatile organic constituents of environmental tobacco smoke (ETS) were determined using an environmental chamber, where ETS is the sole source of target compounds. ETS was generated in an environmental chamber by a number of different cigarettes, including the Kentucky reference cigarette and eight different commercial brands. More than 30 compounds were measured simultaneously for a total of twelve experimental runs. The target compounds are classified into three major classes, i.e. vapor phase ETS markers including 3-ethnylpyridine (3-EP) and nicotine, carbonyl compounds including formaldehyde, and volatile organic compounds (VOCs). The results from the chamber study were used to generate characterized ratios of selected VOCs to 3-EP, a vapor phase ETS marker. Emission factors for VOCs associated with ETS were also estimated. The characteristic ratios appeared to be generally in good agreement with published data obtained by environmental chamber studies similar to this study. This implies that the ratios may be useful for identifying and quantifying the impact of ETS as a source of target compounds in 'real world' indoor environments, which is affected by a complex mixture of multi-sources. The environmental chamber method described here provides a direct and reliable method to compare the ETS generated by different cigarettes. The method can also be applied to the simultaneous determination of many different ETS components.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.1231-1236
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• 2005

Global construction projects manifest more risks than do other industries. Often, firms doing business in construction markets find these risks intimidating. To secure corresponding profits, many global contractors attempt to forecast the effects of risks and establish risk management strategies. However, one key problem with present-day risk management methods is that they are basically analytical or mathematical-oriented approaches which are not easy to adopt in real business. Based on preliminary investigations and evaluations of current tools, this research elicits more practical algorithms for risk checklist by constructing risk scenarios over the whole period of project execution. For the application of the algorithms, a "SE/RF" (Source-Event/Regular-Floating) checklist is suggested, which sorts out risk sources and their subsequent events, as well as dividing various risk factors into either regular or floating categories. In addition, the "PIS" (Probability-Impact-Significance) method is introduced, in place of traditional "PI" (Probability-Impact) methods, by adding the additional criterion of "risk significance" to determine the degree of risk exposure in a more realistic way. As a result, we draw the significant finding that the "PIS" method presents a closer evaluation regarding degree of risk exposure as compared to the level of expert judgments than those from traditional methods. Finally, we provide an integrated procedure for international project risk management with all of the research achievements being incorporated.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제8권7호
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• pp.275-288
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• 2019

본 논문에서는 네트워크에서 충분히 많은 노드가 루머를 들었을 때 그 근원이 어디서부터 시작 되었는지를 추론하는 문제를 고려한다. 이것은 신기술의 확산, 인터넷에서의 컴퓨터 바이러스/스팸 감염, 인기 있는 주제의 tweeting 및 retweeting과 같은 많은 실제 환경에서 네트워크의 정보 확산이 빠르게 진행되고, 이 정보 중 일부는 다른 노드에게 악영향을 미칠 수 있기 때문에 매우 중요한 문제이다. 이 문제는 선행연구에 의해 감염된 노드의 수가 충분히 많으면 정규 트리의 경우에도 탐지 확률이 31%를 초과 할 수 없다는 것이 입증되었다. 이를 바탕으로 네트워크에 감염된 후보 노드에게 몇 가지 추가 질의를 하는 방법에 대해 조사하고 네트워크 관리자가 한정된 자산을 가지고 있을 때 각 노드에 대한 질의의 수를 어떻게 분배하는지에 대한 자산 할당 알고리즘을 제안한다. 마지막으로 제안한 방법에 대하여 다양한 시뮬레이션을 수행하였고 기존 선행 연구보다 우수한 성능을 확인하였다.

• International Journal of Computer Science & Network Security
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• 제22권11호
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• pp.77-86
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• 2022

The destructive impact of contagious diseases outbreaks on all life facets necessitates developing effective solutions to control these diseases outbreaks. This research proposes an end-to-end, data-driven platform which consists of multiple modules that are working in harmony to achieve a concrete goal: early detection of contagious diseases outbreaks (i.e., epidemic diseases detection). Achieving that goal enables decision makers and people in power to act promptly, resulting in robust prevention management of contagious diseases. It must be clear that the goal of this proposed platform is not to predict or forecast the spread of contagious diseases, rather, its goal is to promptly detect contagious diseases outbreaks as they happen. The front end of the proposed platform is a web-based dashboard that visualizes diseases outbreaks in real-time on a real map. These outbreaks are detected via another component of the platform which utilizes data mining techniques and algorithms on gathered datasets. Those gathered datasets are managed by yet another component. Specifically, a mobile application will be the main source of data to the platform. Being a vital component of the platform, the datasets are managed by a DBMS that is specifically tailored for this platform. Preliminary results are presented to showcase the performance of a prototype of the proposed platform.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권1호
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• pp.466-482
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• 2015

IT is the key enabler of digital economy. Appropriate usage of IT can provide a strategic competitive advantage to a firm in a dynamic competitive environment. However, there has been a continuing debate on whether IT can actually enhance the productivity of firms. This concept is called IT productivity paradox. In this study, we analyzed the causality among appropriate indicators to demonstrate the real impact of IT on productivity. The 12,100 sample data from 2011 were used for analysis. As expected, the results indicated that mobile device usage, website adoption, e-commerce, open source, cloud computing, and green computing positively influence IT productivity. This unprecedented large-scale analysis can provide clarification regarding the ambiguous causal mechanism between IT usage and productivity.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2007년도 하계종합학술대회 논문집
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• pp.59-60
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• 2007

Entropy, one of leading metrics on anomalous traffic, attracts researcher's attention since a packet sampling and a traffic volume impact little on entropy value. In this paper, we apply the entropy metric to a domestic network traffic trace which has real anomalous traffics. We used source IP address/port and destination IP address/port that are important attributes of a packet as entropy variable We found that entropy value of multiple-port DoS attack shows something related to a staircase fashion. Also, we show a Possibility of detection of anomalous traffic on small time scale.

• 대한조선학회논문집
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• 제57권6호
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• pp.322-330
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• 2020

This study deals with underwater explosion (UNDEX) characteristics of various non-explosive underwater shock sources for the development of non-explosive underwater shock testing devices. UNDEX can neutralize ships' structure and the equipment onboard causing serious damage to combat and survivability. The shock proof performance of naval ships has been for a long time studied through simulations, but full-scale Live Fire Test and Evaluation (LFT&E) using real explosives have been limited due to the high risk and cost. For this reason, many researches have been tried to develop full scale ship shock tests without using actual explosives. In this study, experiments were conducted to find the characteristics of the underwater shock waves from actual explosive and non-explosive shock sources such as the airbag inflators and Vaporizing Foil Actuator (VFA). In order to derive the empirical equation for the maximum pressure value of the underwater shock wave generated by the non-explosive impact source, repeated experiments were conducted according to the number and distance. In addition, a Shock Response Spectrum (SRS) technique, which is a frequency-based function, was used to compare the response of floating bodies generated by underwater shock waves from each explosion source. In order to compare the magnitude of the underwater shock waves generated by each explosion source, Keel Shock Factor (KSF), which is a measure for estimating the amount of shock experienced by a naval ship from an underwater explosionan, was used.

• 한국기록관리학회지
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• 제20권4호
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• pp.229-236
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• 2020

코로나바이러스감염증은 인류사회가 경험하지 못한 커다란 충격과 생활양식의 급속한 변화를 만들고 있다. 비대면 사회는 감염병 확산을 예방하기 위한 과정에서 보편화된 사례이다. 코로나바이러스감염증으로 인한 사회적 영향은 광범위하다. 정부의 정책, 개인 정보보호, 정보기술 등 다양한 이슈가 사회 전반에 영향을 주고 있다. 동시에 관련 사건과 이슈가 신속하고 빠르게 변하기 때문에 사실 정보를 추적하고 기록하는 것이 어렵다. 코로나-19와 실시간성 정보를 효과적으로 기술하기 위한 방안은 무엇일까? "코로나-19:우리의 기억" 프로젝트는 코로나바이러스감염증에 대한 사회문화적 영향을 가치중립적으로 기록하기 위한 시도이다. 주요 사건과 이슈를 분야별로 수집하고, 중립적인 관점으로 핵심이벤트를 기록하며, 모든 기록을 탐색할 수 있도록 디지털 아카이브로 구축한다. 프로젝트를 통해 수집, 구축한 모든 데이터, 소스코드, 시각화를 포함하는 애플리케이션은 모두 공개하여 새로운 협업을 이끌어내고 있다.

• 환경영향평가
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• 제13권6호
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• pp.285-294
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• 2004

The purpose of this study is to understand the quantitative change of water resources using RMS(Remote Monitoring System) which takes real time data with high reliability. Also, the characteristic of stormwater runoff was understood by the application of the above system for three streams (Jiam, Yulmun, and Gongji stream) in Chuncheon City. The detailed results of these studies are as follows; RMS(Remote Monitoring System) was constructed by the combination of the automatic water-level meter, which measures water-level of streams at all times, and the wireless communication system sending real-time data from the meter. This system is used to evaluate the stormwater runoff in watersheds and the quantitative changes of streams. It is possible to overcome the limit of field investigations needed, which takes a lot of manpower and time, and it is very efficient to provide the reliable flowrate data. Also, it can be applied to the disaster prevention system for flood because the change of flowrate in stream is monitored at real-time. For 3 streams with different watershed characteristics, correlation equations induced from the relation analysis results. In terms of the relation between water-level and flowrate, flowrate was increased rapidly as the water-level rises in case of small watershed and steep slope. The application results of the proposed system for 3 streams (Jiam, Yulmun, Gongji) in Chuncheon city are as follows; The remote monitoring system was very useful for acquisition of the flow rate in stream that are basic data to understand pollutants runoff in watershed. In case of no-rainy day, the runoff ratio for pollutant loading rate was the highest level in Yulmun stream(BOD:2.3%, TN:20.2%, TP:1.2%). So, it shows the management of pollution source is needed such as rehabilitation of sewer line. Runoff ratio of total phosphorus by rainfall in Gongji watershed was increased about 19 times than no-rainy day, which is estimated as the influence of sewer overflow.

• 한국경제지리학회지
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• 제17권3호
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• pp.502-516
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• 2014

본 연구는 한국노동패널을 이용하여 지니계수를 분해와 패널분석을 통해 부동산소득이 가구 소득불평등에 미치는 영향을 실증분석하였다. 공간적 범위를 전국, 수도권, 비수도권으로 나누었고 글로벌금융위기 전 후로 기간을 살펴보았다. 분석결과, 첫째, 전기간을 전국, 수도권, 비수도권으로 나누어 지니계수 분해를 이용해 소득 원천별로 나누어 살펴본 결과, 총소득에서 전국과 수도권은 부동산소득이 차지하는 절대적, 상대적 기여도가 가장 크게 나타난 반면 비수도권은 근로소득이 가장 크게 나타났다. 또한 전국과 수도권은 부동산소득이 가구 소득불평등을 가장 심화시키는 것으로 나타났다. 둘째, 금융위기 이후기간이 이전기간에 비해 가구 소득불평등에 부동산소득이 영향을 덜 미치는 것으로 나타났다. 이는 글로벌금융위기 이전에는 부동산가격이 급등을 하여 가구 소득불평등을 심화시켰으나 이후기간에는 가격하락으로 수익성이 악화돼 일시적으로 약화된 것으로 판단된다. 셋째, 상관관계분석에서 가구주 연령이 높고 고졸미만의 학력의 가구는 다른 가구에 비해 가구총소득이 낮을 것이며, 원천별 소득 특히 근로소득이 높을수록 가구 총소득이 상대적으로 높았다. 넷째, 수도권과 비수도권 지역으로 구분한 가구소득 결정요인을 패널분석한 결과를 비교하면 근로소득, 금융소득과 기타소득의 영향은 비수도권지역이 수도권지역에 비해 높은 반면 부동산소득의 영향은 수도권지역이 비수도권지역에 비해 높은 것을 알 수 있다. 정부는 소득불평등을 줄이기 위해서 고소득층에 세금을 강화하고 저소득층에 대한 세금 감면을 할 수 있는 정책적 배려가 필요하며 다양한 일자리 창출을 위한 노력을 기울여야 한다. 또한 자산보유를 통해 창출하는 소득의 비중이 높아질수록 소득불평등이 악화하는 경향이 있는 만큼 부동산가격 안정화에 중점을 두면서 지역별 차별성을 두고 정책을 수립 집행할 필요성이 있다.