• Title/Summary/Keyword: 데이터 처리량

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Analysis on Energy Consumption Required for Building DTLS Session Between Lightweight Devices in Internet of Things (사물인터넷에서 경량화 장치 간 DTLS 세션 설정 시 에너지 소비량 분석)

  • Kwon, Hyeokjin;Kang, Namhi
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.8
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    • pp.1588-1596
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    • 2015
  • In the Internet of Things (IoT), resource-constrained devices such as sensors are capable of communicating and exchanging data over the Internet. The IETF standard group has specified an application protocol CoAP, which uses UDP as a transport protocol, allows such a lightweight device to transmit data. Also, the IETF recommended the DTLS binding for securing CoAP. However, additional features should be added to the DTLS protocol to resolve several problems such as packet loss, reordering, fragmentation and replay attack. Consequently, performance of DTLS is worse than TLS. It is highly required for lightweight devices powered by small battery to design and implement a security protocol in an energy efficient manner. This paper thus discusses about DTLS performance in the perspective of energy consumption. To analyze the performance, we implemented IEEE 802.15.4 based test network consisting of constrained sensor devices in the Cooja simulator. We measured energy consumptions required for each of DTLS client and server in the test network. This paper compares the energy consumption and amount of transmitted data of each flight of DTLS handshake, and the processing and receiving time. We present the analyzed results with regard to code size, cipher primitive and fragmentation as well.

Design and Implementation of an In-Memory File System Cache with Selective Compression (대용량 파일시스템을 위한 선택적 압축을 지원하는 인-메모리 캐시의 설계와 구현)

  • Choe, Hyeongwon;Seo, Euiseong
    • Journal of KIISE
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    • v.44 no.7
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    • pp.658-667
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    • 2017
  • The demand for large-scale storage systems has continued to grow due to the emergence of multimedia, social-network, and big-data services. In order to improve the response time and reduce the load of such large-scale storage systems, DRAM-based in-memory cache systems are becoming popular. However, the high cost of DRAM severely restricts their capacity. While the method of compressing cache entries has been proposed to deal with the capacity limitation issue, compression and decompression, which are technically difficult to parallelize, induce significant processing overhead and in turn retard the response time. A selective compression scheme is proposed in this paper for in-memory file system caches that rapidly estimates the compression ratio of incoming cache entries with their Shannon entropies and compresses cache entries with low compression ratio. In addition, a description is provided of the design and implementation of an in-kernel in-memory file system cache with the proposed selective compression scheme. The evaluation showed that the proposed scheme reduced the execution time of benchmarks by approximately 18% in comparison to the conventional non-compressing in-memory cache scheme. It also provided a cache hit ratio similar to the all-compressing counterpart and reduced 7.5% of the execution time by reducing the compression overhead. In addition, it was shown that the selective compression scheme can reduce the CPU time used for compression by 28% compared to the case of the all-compressing scheme.

인터넷 기반 원스톱서비스 시스템 개발에 관한 연구+ -수출컨테이너화물 원스톱서비스 시스템 개발-

  • 박남규;최형림;김현수;박영재;조재형;이철우
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 1999.10a
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    • pp.299-308
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    • 1999
  • 오늘날 우리 나라가 당면한 최우선 경제과제중 하나는 물류부분의 혁신을 통한 국가경쟁력 강화라고 할 수 있으며, 이를 위해 정부도 1993년 물류체계 개선을 위한 장기구상으로 ‘화물유통체계 개선 10개년 기본계획’을 수립하여 적극 추진 중에 있다. 그러나 이러한 노력에도 불구하고 PORT-MIS사용자를 상대로 한 설문조사에서는 선박입출항 업무 관련 서류의 40%, 항만시설 사용 업무와 관련된 서류의 31%, 하역업무 관련 서류의 10%만이 EDI를 활용하고 있었다. EDI 활용이 저조한 사유로는 전송시간이 많이 걸리며, EDI 소프트웨어가 작동되지 않으며, 수신확인이 되지 않기 때문이라 응답을 하였다. 이처럼 오늘날 항만물류산업이 겪고 있는 물류 데이터 흐름이 단절적 현상은 시간이 흐를수록 해결 될 기미가 보이고 있지 않다. 따라서 본 논문에서는 우리 나라가 겪고 있는 물류관련 업무를 한번의 데이터 입력으로 해결할 수 있는 원스톱 서비스 시스템개발을 목표로 우선 PORT-MIS EDI 업무를 처리할 수 있는 시스템을 구축하였다. 이는 향후 화주, 운송사, 선사, 포워더, 창고업자,하역회사, 철도청, 화물터미널, 컨테이너 터미널, 해양수산청, 관세청, 출입국관리사무소, 검역소 사이에 서로 교환되는 적하목록, Booking List, 컨테이너 Pick up정보, 위험물 정보, COPINO 정보를 비롯하여 대 관세청 신고 등 수출컨테이너 화물업무의 전반적인 영역으로까지 쉽게 확대할 수 있을 것이다. 본 연구결과 구축된 시스템은 원천정보를 중앙의 통합데이터베이스에 저장하여 이를 사용자의 요구에 의해 인터넷을 통해 전달하는 FTP와 웹 EDI 방식을 결합한 하이브리드 형태이다.CS Cell 방식에 의한 위치결정방식을 채택하였는데, 이것은 PCS망을 기반으로 데이터를 주고받이며 인터넷 단말기로 확장 가능한 PCS 단말기를 사용해서 위치추적을 하는 시스템이다. 이러한 시스템을 선정하게된 배경은 단말기아 망 이용료의 가격이 저렴하여 현실적으로 트럭이 쉽게 부착할 수 있다는 장점이 있으며 나아가 인터넷 단말기를 활용하여 차량과 관제센터사이에 메시지 전송 등 부가적인 서비스가 가능하기 때문이다.비교한 결과 토사 유출 억제효과는 한지형과 나지형잔디들의 혼합형(MixtureIII)과 자생처리구(MixtureV), Italian ryegrass와 자생식물의 혼합형(MixtureIV)등에서 비교적 낮은 수치를 토사유출량을 기록하였다. 이러한 결과는 자생식물들이 비록 초기생육속도는 외래도입초종에 떨어지지만 토사유출의 억제효과면에서는 이들 외래초종에 필적할 수 있음을 나타낸다고 할 수 있겠다.중량이 약 115kg/$m^2$정도로 나타났다.소 들(환경의 의미, 사람의 목적과 지식)보다 미학적 경험에 주는 영향이 큰 것으로 나타났으며, 모든 사람들에게 비슷한 미학적 경험을 발생시키는 것 이 밝혀졌다. 다시 말하면 모든 사람들은 그들의 문화적인 국적과 사회적 인 직업의 차이, 목적의 차이, 또한 환경의 의미의 차이에 상관없이 아름다 운 경관(High-beauty landscape)을 주거지나 나들이 장소로서 선호했으며, 아름답다고 평가했다. 반면에, 사람들이 갖고 있는 문화의 차이, 직업의 차 이, 목적의 차이, 그리고 환경의 의미의 차이에 따라 경관의 미학적 평가가 달라진 것으로 나타났다.corner$적 의도에 의한 경관구성의 일면을 확인

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Behavior Evaluation of Thin Bonded Continuously Reinforced Concrete Overlay on Aged Jointed Concrete Pavement(2) (노후 줄눈 콘크리트 포장 보수를 위한 얇은 연속 철근 콘크리트 덧씌우기 포장의 거동 평가(2))

  • Ryu, Sung-Woo;Cho, Yoon-Ho
    • International Journal of Highway Engineering
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    • v.12 no.4
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    • pp.101-110
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    • 2010
  • In this paper, it has been studied about the CRCO to maintain or rehabilitate the aged JCP. The CRCO and JCO was constructed at useless section of Seo-Hae-Ahn express highway in South Korea. The performance evaluation was conducted. Especially, it was focused on the roll of longitudinal reinforced steels inserted into the CRCO. On crack survey results from field construction section, the reflection cracks at joint of the existing pavement occurred in CRCO. However, due to the constraints of longitudinal reinforced steels, crack width was small. Total crack length and quantity in the CRCO more than that in the JCO. And crack spacing in the CRCO was narrower than it in the CRCP. Through the bonding strength test results, if the cold milling and cleaning as well as surface treatment is applied, there will be no debonding problem at interlayer in the early age. From analysis of the horizontal behavior at the joint, the longitudinal reinforced steels constrained crack width which became wider than initial state over time. Also, that steel in the CRCO reduced the horizontal movement due to temperature variation(4 times than that in the JCO). But, if interface is debonded, the roll decreased. Vertical VWG data showed that CRCO did not occur debonding problem at steel location, but there was some problem in JCO. It was confirmed by field coring. The tensile strain appeared in the CRCO, But the compressive strain occurred in the JCO in early age. Through the FWD test result, deflection in the CRCO was less than that in the JCO. And K value in the CRCO was greater than it in the JCO.

A Feature Based Approach to Extracting Ground Points from LIDAR Data (LIDAR 데이터로부터 지표점 추출을 위한 피쳐 기반 방법)

  • Lee, Im-Pyeong
    • Korean Journal of Remote Sensing
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    • v.22 no.4
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    • pp.265-274
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    • 2006
  • Extracting ground points is the kernel of DTM generation being considered as one of the most popular LIDAR applications. The previous extraction approaches can be mostly characterized as a point based approach, which sequentially examines every individual point to determine whether it is measured from ground surfaces. The number of examinations to be performed is then equivalent to the number of points. Particularly in a large set, the heavy computational requirement associated with the examinations is obviously an obstacle to employing more sophisticated criteria for the examination. To reduce the number of entities to be examined and produce more robust results, we developed an approach based on features rather than points, where a feature indicates an entity constructed by grouping some points. In the proposed approach, we first generate a set of features by organizing points into surface patches and grouping the patches into surface clusters. Among these features, we then attempt to identify the ground features with the criteria based on the attributes of the features. The points grouped into these identified features are labeled ground points, being used for DTM generation afterward. The Proposed approach was applied to many real airborne LIDAR data sets. The analysis on the results strongly supports the prominent performance of the proposed approach in terms of not only the computational requirement but also the quality of the DTM.

Reconfiguration of Physical Structure of Vegetation by Voxelization Based on 3D Point Clouds (3차원 포인트 클라우드 기반 복셀화에 의한 식생의 물리적 구조 재구현)

  • Ahn, Myeonghui;Jang, Eun-kyung;Bae, Inhyeok;Ji, Un
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.40 no.6
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    • pp.571-581
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    • 2020
  • Vegetation affects water level change and flow resistance in rivers and impacts waterway ecosystems as a whole. Therefore, it is important to have accurate information about the species, shape, and size of any river vegetation. However, it is not easy to collect full vegetation data on-site, so recent studies have attempted to obtain large amounts of vegetation data using terrestrial laser scanning (TLS). Also, due to the complex shape of vegetation, it is not easy to obtain accurate information about the canopy area, and there are limitations due to a complex range of variables. Therefore, the physical structure of vegetation was analyzed in this study by reconfiguring high-resolution point cloud data collected through 3-dimensional terrestrial laser scanning (3D TLS) in a voxel. Each physical structure was analyzed under three different conditions: a simple vegetation formation without leaves, a complete formation with leaves, and a patch-scale vegetation formation. In the raw data, the outlier and unnecessary data were filtered and removed by Statistical Outlier Removal (SOR), resulting in 17%, 26%, and 25% of data being removed, respectively. Also, vegetation volume by voxel size was reconfigured from post-processed point clouds and compared with vegetation volume; the analysis showed that the margin of error was 8%, 25%, and 63% for each condition, respectively. The larger the size of the target sample, the larger the error. The vegetation surface looked visually similar when resizing the voxel; however, the volume of the entire vegetation was susceptible to error.

Estimation pollutant load and rate of contribution in inflow streams of Sin-gal reservoir during the raining season (강우시 신갈호 유입하천의 오염부하량 및 기여율 산정)

  • Jung, Jae-Hoon;Ahn, Tae-Woong;Choi, I-Song;Oh, Jong-Min
    • Proceedings of the Korea Water Resources Association Conference
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    • 2009.05a
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    • pp.966-970
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    • 2009
  • 경기도 용인시, 오산시와 화성시 지역의 농업용수와 공업용수의 공급원으로 이용되고 있는 신갈호는 현재 유입하천으로부터 미처리된 도시하수, 공장 폐수, 축산 폐수 등의 점오염원 및 도시 지역 불투수층에 쌓여있는 오염물질인 비점오염원이 무분별하게 유입되어 수질이 매우 악화되어 용수로의 사용이 어려운 지경에 달하였으며, 자연정화능력도 감소하는 등 심각하게 오염되었다. 또한 최근에는 신갈호 유역의 개발에 따른 토지이용 변화로 신갈호 유역의 총오염부하량이 증가하고 있는 실정이다. 따라서 본 연구에서는 현재 날로 심각해지는 신갈호 유입하천의 비점오염원 조사를 통해 신갈호 및 유입하천의 기초데이터의 확충 및 현황 파악을 하고자 하였다. 본 연구에서는 강우 시 신갈호로 유입되는 3개의 유입지천인 신갈천(SG), 지곡천(JK), 공세천(KS)에서 비점오염부하량을 산정함으로써 강우 시 호소로 유입되는 총오염부하량 및 비점오부하량의 비율을 알아보고자 하였다. 강우사상에 따른 총 오염물질 부하량은 EMC 농도를 구한 후 총 유출유량을 곱하고 총 강우지속시간을 곱하여 산정하였다. 조사결과 강우기에 있어서 거의 모든 항목의 농도는 평수기보다 매우 높은 수치를 나타냈다. 특히 SS 농도는 토사의 하천유입으로 인해 다른인자에 비해 큰 변동폭을 나타내었으며, COD와 T-P는 토양입자에 흡착되어 함께 이동하기 때문에 SS와 밀접한 관계를 가졌다. 강우시의 각 유입하천별 오염부하 기여율은 SG의 경우 SS 74.1%, BOD 64.4%, COD 65.7%, T-N 63.8%, T-P 73.8%를 나타내었다. JK의 경우 SS 25.4%, BOD 31.5%, COD 30.5%, T-N 32.5%, T-P 24.2% 였고, KS의 경우 SS 0.5%, BOD 4.1%, COD 3.8%, T-N 3.7%, T-P 2.0%를 나타내었다. 강우시의 각 유입하천별 오염부하 기여율을 평수기때의 오염부하 기여율과 비교하였다. 비교결과 SS의 경우는 SG가 강우시에 74%, 평수기에 83%, BOD의 경우는 강우시 64%, 평수기 80%, T-N은 강우시 64%, 평수기에 84%, T-P의 경우는 강우시 74%, 평수기에 82%로 모든 항목에서 평수기에 신갈천이 신갈호의 오염부하에 미치는 영향이 큰 것으로 나타났는데, 이는 강우시 지곡천의 기여율이 평수기 보다 상대적으로 높아지기 때문인 것으로 판단된다.

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Factors Affecting the Minimum Detectable Activity of Radioactive Noble Gases (방사성 노블가스 측정을 위한 최소검출방사능 산출의 조절인자)

  • Park, Ji-young;Ko, Young Gun;Kim, Hyuncheol;Lim, Jong-Myoung;Lee, Wanno
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.16 no.3
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    • pp.301-308
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    • 2018
  • Anthropogenic radioactive noble gases formed by nuclear fission are significant indicators used to monitor the nuclear activity of neighboring countries. In particular, radioactive xenon, owing to its abundant generation and short half-life, can be used to detect nuclear testing, and radioactive krypton has been used as a tracer to monitor the reprocessing of nuclear fuels. Released radioactive noble gases are in the atmosphere at infinitesimal amounts due to their dilution in the air and their short half-life decay. Therefore, to obtain reliable and significant data when performing measurement of noble gases in the atmosphere, the minimum detectable activity (MDA) for noble gases should be defined as low as possible. In this study, the MDA values for radioactive xenon and krypton were theoretically obtained based on the BfS-IAR system by collecting both noble gases simultaneously. In addition, various MDA methods, confidence level and analysis conditions were suggested to reduce and optimize MDA with an assessment of the factors affecting MDA. The current investigation indicated that maximizing the pretreatment efficiency and performance maintenance of the counter were the most important aspects for Xe. In the case of Kr, since sample activities are much higher than those of Xe, it is possible to change the target MDA or to simplification of the analysis system.

Direct Reconstruction of Displaced Subdivision Mesh from Unorganized 3D Points (연결정보가 없는 3차원 점으로부터 차이분할메쉬 직접 복원)

  • Jung, Won-Ki;Kim, Chang-Heon
    • Journal of KIISE:Computer Systems and Theory
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    • v.29 no.6
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    • pp.307-317
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    • 2002
  • In this paper we propose a new mesh reconstruction scheme that produces a displaced subdivision surface directly from unorganized points. The displaced subdivision surface is a new mesh representation that defines a detailed mesh with a displacement map over a smooth domain surface, but original displaced subdivision surface algorithm needs an explicit polygonal mesh since it is not a mesh reconstruction algorithm but a mesh conversion (remeshing) algorithm. The main idea of our approach is that we sample surface detail from unorganized points without any topological information. For this, we predict a virtual triangular face from unorganized points for each sampling ray from a parameteric domain surface. Direct displaced subdivision surface reconstruction from unorganized points has much importance since the output of this algorithm has several important properties: It has compact mesh representation since most vertices can be represented by only a scalar value. Underlying structure of it is piecewise regular so it ran be easily transformed into a multiresolution mesh. Smoothness after mesh deformation is automatically preserved. We avoid time-consuming global energy optimization by employing the input data dependant mesh smoothing, so we can get a good quality displaced subdivision surface quickly.

The Study of Volume Data Aggregation Method According to Lane Usage Ratio (차로이용률을 고려한 지점 교통량 자료의 집락화 방법에 관한 연구)

  • An Kwang-Hun;Baek Seung-Kirl;NamKoong Sung
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.4 no.3 s.8
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    • pp.33-43
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    • 2005
  • Traffic condition monitoring system serves as the foundation for all intelligent transportation system operation. Loop detectors and Video Image Processing are the most widely common technology approach to condition monitoring in korea Highways. Lane Usage is defined as the proportion of total link volume served by each lane. In this research, the lane Usage(LU) of two lane link for one day. Interval is 56% : 44%. The LU of three lane link is 39% : 37% : 24%. The LU of four lane link is 25% : 29% : 26% : 21%. These analysis reveal that each lane distributions of link are not same. This research investigates the general concept of lane usage by using collected loop detector data and the investigated that lane distribution is different by traffic lane and lane usage is consistent by time of day.

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