• 한국지하수토양환경학회지:지하수토양환경
• /
• 제20권7호
• /
• pp.53-60
• /
• 2015

This study suggested the new site classification system according to land use, type of contamination and contaminants. Because the present site classification system can not cover all the areas, we changed the concept of land use to more detail one and enlarged the concept of other areas to cover all the areas not defined as certain land use. In case of the present industrial area, it was merged as other areas to avoid the confusion with oil and toxic material storage tank farm area. Accident area was separated from other areas and defined as only accident area caused by the mobile storage facility. In addition to classify the sites according to the basic land use, we classify the sites again in lower level according to the type of contamination and contaminants. With this classification system, we proposed different soil sampling strategy with the consideration of the origin of contamination and the interactions between soil and contaminants. We removed the surface soil sample (0~15 cm depth) around above storage tank because it was not a effective sample to assess whether that area contaminated or not. We also proposed to take the deeper soil samples at minimum three sampling points to confirm the depth of contamination in exploratory soil survey. We also proposed to remove the one point of 15 m depth sampling because it is not effective to confirm contaminated soil depth and needs the exhausted labor and cost. Instead of doing this, we added the continuous sampling to uncontaminated subsoil. Soil sampling points and depth in detailed soil survey is determined based on the results of exploratory soil survey. Therefore, effectiveness and reinforcements of exploratory soil survey would play an important role in improving the reliability of detailed soil survey.

• Journal of information and communication convergence engineering
• /
• 제18권1호
• /
• pp.28-32
• /
• 2020

Railway transportation is the main land-based transportation in most countries. Accordingly, railway-transportation safety has always been a key issue for many researchers. Railway pedestrian accidents are the main reasons of railway-transportation casualties. In this study, we conduct experiments to determine which of the latest convolutional neural network models and algorithms are appropriate to build pedestrian railroad accident prevention systems. When a drone cruises over a pre-specified path and altitude, the real-time status around the rail is recorded, following which the image information is transmitted back to the server in time. Subsequently, the images are analyzed to determine whether pedestrians are present around the railroads, and a speed-deceleration order is immediately sent to the train driver, resulting in a reduction of the instances of pedestrian railroad accidents. This is the first part of an envisioned drone-based intelligent security system. This system can effectively address the problem of insufficient manual police force.

• 한국실천공학교육학회논문지
• /
• 제4권2호
• /
• pp.162-170
• /
• 2012

로봇이 수많은 작업을 수행하고 목표를 향해서 진행하기 위해서는 무엇보다 위치를 인식하는 것이 대단히 중요하다. 본 논문에서는 랜드 마크와 센서 네트워크 환경하에서 주행하는 로봇의 위치를 구별할 수 있는 위치 인식시스템을 제안한다. 전적으로 기본 지능형 로봇에 위치 인식 시스템과 환경 센서 모듈을 부가하여 구현하고, 이를 컴퓨터 시뮬레이션을 통해서 제안된 알고리즘이 합당함을 검증한다.

• 디지털산업정보학회논문지
• /
• 제8권3호
• /
• pp.49-55
• /
• 2012

Recently, with the rapid development of android-based smartphones, it is becomes a major security issue that the case of Android platform is an open platform. so it is easy to be a target of mobile virus penetration and hacking. Even there are a variety of security mechanisms to prevent the vulnerable points of the Android platform but the reason of most of the security mechanisms were designed at application-level that highly vulnerable to the attacks directly to the operating system or attacks using the disadvantages of an application's. It is necessary that the complementary of the android platform kernel blocks the kernel vulnerability and the application vulnerability. In this paper, we proposed a secure system using linux-based android kernel applied to LIDS(Linux Intrusion Detection and Defense System) and applied a smart phone with s5pc110 chip. As a result, the unauthorized alteration of the application was prevented with a proposed secure system.

• 지적과 국토정보
• /
• 제46권1호
• /
• pp.59-74
• /
• 2016

최근 기후변화에 따른 집중호우로 인해 도심지 옹벽 및 축대붕괴, 토사유실 그리고 산사태가 발생하고 있다. 본 연구에서는 토양도, DEM, 토지피복도와 같은 공간정보를 RUSLE 모델에 적용하여 토사유실모델링을 수행하였다. 특히 토사유실량을 지적도와 연계하여 필지별로 토사유실 및 단위토사유실 등급도를 작성하였으며, 토사유실 등급별로 필지수를 계산할 수 있었다. 또한 도시계획이나 건설 분야에서 토사유실 등급을 현장에서 확인할 수 있도록 모바일 GIS 기반의 토사재해정보시스템을 개발하였다. 토사재해정보시스템을 통해 토지대장, 건축물대장 그리고 도로구간대장에 대한 현황을 확인할 수 있으며, 필지별로 RUSLE 인자와 토사유실량 그리고 토사재해등급을 확인할 수 있었다. 또한 행정동과 토사유실등급별로 해당 필지의 위치와 속성을 검색함으로써 현장에서 토사재해업무를 효과적으로 지원할 수 있을 것으로 판단된다.

• Journal of information and communication convergence engineering
• /
• 제8권5호
• /
• pp.602-607
• /
• 2010

Recently, one has realized that the threedimensional positioning technique used in GPS can be effectively applied to the modern two-dimensional positioning. Such a technique might has applied to the twodimensional positioning in fields of the mobile communication, eLORAN and the GPS jamming/ electronic warfare system. In the paper, we have studied on algorithms for two-dimensional positioning based on GPS Pseudorange Technique. The main works and results are summarized below. First, the linearized state equation was mathematically derived based on GPS pseudorange technique. Second, the geometry model with respect to triangles formed using unit-vectors were proposed for investigation of land-based radio positioning. Finally, the corresponding mathematical formulations for DOP values and covariance matrix were designed for two-dimensional positioning.

• 한국통신학회논문지
• /
• 제7권1호
• /
• pp.37-45
• /
• 1982

육상 移重무선통신상에 있어서 2相 DPSK 방식에 대한 가우스 잡음과 多重路 동일주파 간섭파의 영향에 관해 이론해석을 행했다. 해석방법으로서는 多重통신로는 비선택성 Rayleigh통신로로 간주, DPSK 검파기 출력의 確率密度雨數를 유도하여, DPSK방식의 수신誤率의 일반식을 구했다. 수치해석 결과로서 반송파대 잡음전력비(CNR)의 변화에 따른 수신誤率를 반송파대 간섭파전력비(CIR)와 희망신호의 상관계수를 파라메타로 하여 그림으로 나타내고 이를 분석, 검토했다.

• Journal of Advanced Marine Engineering and Technology
• /
• 제34권8호
• /
• pp.1159-1164
• /
• 2010

기존 해상의 데이터통신은 주로 위성과 라디오에 의존적이나 전송률과 비용 측면에서 제약을 가진다. 향후의 수요에 대비하여 육상의 통신체제와 유사하게 저렴하고 비교적 높은 전송률을 제공하는 새로운 해상통신체제가 필요하다. 이 논문에서는 선박간의 데이터통신을 위해 새롭게 설계된 해상통신망 모델을 보이고, 선박에서 이용할 수 있는 여러 무선매체 가운데 응용의 특성과 통신제약조건에 최적인 매체를 선택하여 경로를 배정하는 MWR 라우팅 프로토콜을 제안한다.

• 한국통신학회논문지
• /
• 제23권4호
• /
• pp.1113-1120
• /
• 1998

This paper introduces a channel model that is a combination of Rice and log-normal statistics, with independent shadowing affectingeach direct and diffuse component, repectively. This model extends the channel model of a combined Rice and Log-normal, proposed by Corazza, to include the independent shadowing. The validity of model is confirmed by comparisons with the data collectedin the literature, the analytical model, and the computer model in terms of probability distribution of the evvelope of each model. The model turns out to be one of many well-known narrowband models in limiting cases, e.g. Rayleigh, Rice, log-normal, Suzuki, Loo, and Corazza. Finally, the examples of bit error probability evaluations for several values of the elevation angle in the channel are provided.

• 한국통신학회논문지
• /
• 제15권7호
• /
• pp.565-573
• /
• 1990

본 논문에서는 육상 이동통신의 채널 환경인 fast Rayleigh 페이딩 상황하에서 discriminator형 GMSK변복조기의 수신 대역 필터에 의한 성능을 분석한 S.Elnoubi의 유도식을 이용하여 BbT=0.25인 경우의 최적 수신 대역폭을 시뮬레이션하였으며, 실제 실험장치를 구현하여 측정한 결과와 비교 검토하였다. 그 결과 static 페이딩(fbT=0)인 경우에는 BrT=0.7이 최적이나 fast 페이딩(fDT>0)인 경우에는 Eb/No의 비가 크고, 페이딩 rate fDT가 클수록 필터에 의한 영향이 작다는 결론을 얻었다.