• 한국물환경학회지
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• 제31권2호
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• pp.196-208
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• 2015

This study analyzed the characteristics of sewer flow and its water quality, and investigated changes in the characteristics in three areas where the sewer rehabilitation projects have been carried out. In S1 area, the patterns of the flow became regular and the range of the fluctuation decreased after the sewer rehabilitation. The flow and its BOD concentration increased. The infiltration/inflow and exfiltration showed clear distinction before and after the sewer rehabilitation in this area. In S2 area, the patterns and the range of the fluctuation of the flow made no differences before and after the sewer rehabilitation. The flow decreased slightly and its BOD concentration increased considerably after the sewer rehabilitation. Big decrement in stormwater inflow but small in exfiltration appeared in this area. In S3 area, the patterns and the range of the fluctuation of the flow made no differences before and after the sewer rehabilitation. The flow decreased slightly and its BOD concentration increased in a small rate in this area.

• 한국안전학회지
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• 제33권5호
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• pp.51-59
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• 2018

It is difficult to determine the outdoor toxic level of hazardous chemicals that are leaked in the building, since there are no efficient ways to calculate how much percentage of the leaked chemicals is released into the outdoor atmosphere. In address to these problems, we propose a reasonable box model that can quantitatively evaluate the mass rate of the indoor chlorine leakage into the outside of the building. The proposed method assumes that the indoor chlorine leakage is fully mixed with the indoor air, and then the mixture of the chlorine and indoor air is exfiltrated into the outside of the building through effective leakage areas of the building. It is found that the exfiltration rate of the mixture of the chlorine and indoor air is strongly dependent on the temperature difference between inside and outside the building than the atmospheric wind speed. As compared with a conventional method that uses a vague mitigation factor, our method is more effective to evaluate the outdoor toxic threat zone of the chlorine that are leaked in the building, because it can consider the degree of airtight of the building in the evaluation of the threat zone.

• 한국산학기술학회논문지
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• 제17권9호
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• pp.440-446
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• 2016

군사 비밀이나 조직의 기밀 데이터는 그 조직의 매우 중요한 자원이며 외부로부터의 접근이 차단되어야 한다. 그러나 최근 인터넷의 접근성이 높아짐으로써 보안이 중요한 이슈로 부상하고 있다. 이를 위해 네트워크 내부에 대한 공격이나 침입행위를 탐지하는 이상 행위 탐지 방법이 제안되었다. 그러나 대부분의 이상 행위 탐지는 외부로부터의 침입에 대한 측면만 다루고 있으며, 공격이나 침입보다 더 큰 피해를 입히는 내부 데이터의 유출에 대해서는 다루고 있지 않다. 또한 기존의 이상 행위 탐지 방법을 데이터 유출 탐지에 적용할 경우 네트워크 내부의 환경과 여러 가지 변수들이 고려되어 있지 않기 때문에 많은 문제점들이 발생한다. 따라서 본 논문에서는 데이터 유출 탐지를 위한 이상 행위 탐지(Data Exfiltrating Detection for Anomaly Detection : DEDfAD) 방법의 정확도 향상을 위하여 DEDfAD에서 고려되어야 하는 이슈 사항들에 대하여 기술하고, 프로파일 기반의 탐지 방법과 머신러닝 기반의 탐지 방법으로 분류하여 이들의 장단점을 분석한다. 또한 분류된 접근 방법을 중심으로 이슈들과의 비교분석을 통해 향후 연구 방향을 제시한다.

• 한국농공학회지
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• 제38권5호
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• pp.47-54
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• 1996

본 연구에서는 지표면유출과 중간유출의 수문학적과정을 함께 모의발생 시키는 합성 유역모델이 제시되었다. 본 모델은 디지털지형모델과 상호 연결되도록 하였으며 지형이 복잡한 지역에서도 유출이 시간과 공간적으로 누가계산되어 이 분야의 조사연구에 필요한 정보를 제공할 수 있다. 본모델을 이용 유역의 불투수층 위에 분포해있는 토양의 중간계층과 토양수분의 계산 및 침투/용탈의 과정을 모의 발생시킬 수 있다.

• 설비공학논문집
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• 제14권1호
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• pp.55-62
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• 2002

In this paper, several types of infiltration prevention devices that are currently in use have been studied through experimental investigation. Firstly, the types of infiltration prevention devices were defined through investigating actual conditions of refrigerated warehouse in operates. Based on this investigation results, measured change of temperature and figured out air change rates of the type of infiltration prevention devices by using scale down model. After that, found the amount of air change rate in order to estimate the load of air change easily in facility plan.

• 디지털산업정보학회논문지
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• 제13권2호
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• pp.1-11
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• 2017

In this paper, we design and implement PADIL(Prediction And Detection of Information Leakage) system that predicts and detect information leakage behavior of insider by analyzing network traffic and applying a variety of machine learning methods. we defined the five-level information leakage model(Reconnaissance, Scanning, Access and Escalation, Exfiltration, Obfuscation) by referring to the cyber kill-chain model. In order to perform the machine learning for detecting information leakage, PADIL system extracts various features by analyzing the network traffic and extracts the behavioral features by comparing it with the personal profile information and extracts information leakage level features. We tested various machine learning methods and as a result, the DecisionTree algorithm showed excellent performance in information leakage detection and we showed that performance can be further improved by fine feature selection.

• 상하수도학회지
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• 제20권1호
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• pp.53-62
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• 2006

This study was carried out to obtain quantities of infiltration, inflow and exfiltration on sewer pipes of three areas at a small city. From the results, the most investigated sewer pipes should be infiltrated by underground water and undetermined water. Flowrate commonly showed two peak at 6 to 8 a.m. and 6 to 9 p.m. and which may be influenced by the sewer flowrate with washing or bathing time. BOD/TN ratio of below 4.0 were inferior as compared with proper criteria 5.1. Infiltration/inflow rates of three areas were 21.7% and $0.08m^3/km$ of A, 12.4% and $0.015m^3/km$ of B, 22.4% and $0.021m^3/km$ of C, respectively. This indicates that infiltration/inflow rate of A was obviously greater than that of B and C. Also, these results show that we can conduct sewer maintenance in good order as A, C and B zone.

• 한국물환경학회지
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• 제24권1호
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• pp.107-117
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• 2008

Infiltration facilities are effective instruments to mitigate flood and can increase base runoff in urban watersheds. In order to analyze effects of infiltration trenches physical model experiments were conducted. The physical model facility consists of two soil tanks, artificial rainfall generators, tensiometers, and piezometers. The experiment was conducted by nine times and each case differed in rainfall intensity, rainfall duration and the type of ground surface. Measured quantities in the experiments are as follows: surface runoff, subsurface runoff, trench pipe runoff, groundwater level, water content, etc. The following resulted from the model experiment: The volume of subsurface runoff at trench watershed was maximum 78.3% compared with rainfall. This value is bigger than that of ordinary rate of subsurface runoff, and shows a groundwater recharge effect of trench. The time of runoff passing through the trench became earlier and the volume of runoff became larger with the increase of inflow into the trench, while trench exfiltration into ground became relatively smaller. The results of this study presented above show that infiltration trenches are effective instruments to increase base runoff during dry periods.

• 대한건축학회논문집:구조계
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• 제36권2호
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• pp.155-163
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• 2020

Indoor airborne particles are consisted of outdoor- and indoor-generated particles, which can be characterized by their compositions, generation features and toxicity. The identification of source contribution of indoor and outdoor origin to indoor particles is important to understand PM_2.5 transport in a building as well as its impact on occupant health. The objective of this study is to investigate seasonal source contribution to indoor PM_2.5 concentration depending on airtightness of apartment units. To evaluate the source contribution, particle transport including penetration, generation, exfiltration in an apartment housing unit was simulated by using CONTAM with particle and airflow simulation parameters obtained from field measurements. The result showed that the outdoor source contribution to indoor air was relatively dominant in the leaky housing unit during spring (77.2%) and winter (73.9%), and the indoor source was dominant in the airtight housing unit during summer (60.3%) and fall (60.7%). These results indicate the seasonal health risk of indoor PM_2.5 can be varied according to airtightness of apartment units.

• 한국산학기술학회논문지
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• 제9권6호
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• pp.1523-1528
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• 2008

본 논문에서는 지하주차장 연결통로 및 엘리베이터 홀의 기계식 환기장치의 설치 및 적용을 위한 기초자료를 얻기 위하여 공동주택 지하주차장에 환기장치를 설치하여 실험을 수행하였다. 엘리베이터 홀의 경우 침기 및 누기(자연환기)로 인하여 실제 환기회수는 계산환기회수의 5배 정도 크게 나타났다. 지하 주차장 연결통로 및 엘리베이터홀의 환기장치는 동시 급 배기로 설치하는 것이 좋으며, 설치가 어려울 때에는 차선책으로 급기만이라도 설치하는 것이 공기질 측면에서 좋을 것이라 판단된다. 겨울철 환기장치 가동에 따른 콜드 드래프트의 영향을 고려하여 환기장치의 급기부에 예열기를 설치하는데, 환기시스템의 가동유무 및 가동방법을 다르게 하여도 지하주차장 연결통로 및 엘리베이터 홀의 온도가 $7{\sim}8^{\circ}C$로 일정하게 유지되어 나타나므로 한국의 남부지역에서는 단순 급 배기 환기장치에 예열기를 설치하지 않아도 될 것으로 판단된다.