• 한국지구물리탐사학회:학술대회논문집
• /
• 한국지구물리탐사학회 2007년도 특별 심포지엄 논문집
• /
• pp.31-42
• /
• 2007

Dc resistivity monitoring has been increasingly used in order to understand the changes of subsurface conditions in terms of conductivity. The commonly adopted interpretation approach which separately inverts time-lapse data may generate inversion artifacts due to measurement error. Eventually the contaminated error amplifies the artifacts when reconstructing the difference images to quantitatively estimate the change of ground condition. In order to alleviate the problems, we defined the subsurface structure as four dimensional (4-D) space-time model and developed 4-D inversion algorithm which can calculate the reasonable subsurface structure continuously changing in time even when the material properties change during data measurements. In this paper, we discussed two case histories of resistivity monitoring to study the ground condition change when the properties of the subsurface material were artificially altered by injecting conductive materials into the ground: (1) dye tracer experiment to study the applicability of electrical resistivity tomography to monitoring of water movement in soil profile and (2) the evaluation of cement grouting performed to reinforce the ground. Through these two case histories, we demonstrated that the 4-D resistivity imaging technique is very powerful to precisely delineate the change of ground condition. Particularly owing to the 4-D inversion algorithm, we were able to reconstruct the history of the change of subsurface material property.

• 한국시뮬레이션학회논문지
• /
• 제12권3호
• /
• pp.69-81
• /
• 2003

To manage a cluster of distributed server systems, a number of management aspects should be considered in terms of configuration management, fault management, performance management, and user management. System performance monitoring and reporting take an important role for performance and fault management. In this paper, we present distributed system architecture modeling of a performance monitoring and reporting tool. Modeling architecture of four subsystems are introduced: node agent, data collection, performance management & report, and DB schema. The performance-related information collected from distributed servers are categorized into performance counters, event data for system status changes, service quality, and system configuration data. In order to analyze those performance information, we use a number of ways to evaluate data corelation. By using some results from a real site of a company and from simulation of artificial workload, we show the example of performance collection and analysis. Since our report tool detects system fault or node component failure and analyzes performances through resource usage and service quality, we are able to provide information for server load balancing, in short term view, and the cause of system faults and decision for system scale-out and scale-up, in long term view.

• Journal of Biosystems Engineering
• /
• 제38권1호
• /
• pp.25-32
• /
• 2013

Purpose: The objective of this study is to develop a data middleware for u-IT convergence in agricultural environment monitoring, which can support non-standard data interfaces and solve the compatibility problems of heterogenous sensor networks. Methods: Six factors with three different interfaces were chosen as target data among the environmental monitoring factors for crop cultivation. PostgresSQL and PostGIS were used for database and the data middleware was implemented by Python programming language. Based on hierarchical model design and key-value type table design, the data middleware was developed. For evaluation, 2,000 records of each data access interface were prepared. Results: Their execution times of File I/O interface, SQL interface and HTTP interface were 0.00951 s/record, 0.01967 s/record and 0.0401 s/record respectively. And there was no data loss. Conclusions: The data middleware integrated three heterogenous sensor networks with different data access interfaces.

• 상하수도학회지
• /
• 제11권4호
• /
• pp.91-98
• /
• 1997

At present, automated monitoring of water quality in Han river has been operated at each water treatment plant. But the automated measurement sites must be choosen newly because water source in Seoul move to the upper stream of Chamshil weir. In this study, automated monitoring sites in Han river were reviewed, and the proper sites for automated monitoring of water quality have been selected by Qual2E model, RMA model, water sampling guidline, Sanders' method and topograpical characteristics of Han river in order to resonable operate. 8 sites have been selected as follows: (1) the site of immediately after Paldang drainage (2) the left site and a right site of $Gu{\check{u}}i$ water intake (3) the left site and a right site at Noryangjin(Han river bridge) (4) the site between Shingok weir and Anyangchun confluence point(Hangju bridge) (5) the site of Chungryangchun downstream(existence) (6) the site of Tanchun downstream(existence) (7) the site of Anyangchun downstream(existence) (8) the site of Wangsukchun downstream. The results proposed resonable operating management of network and economical system built up.

• Safety and Health at Work
• /
• 제9권4호
• /
• pp.479-485
• /
• 2018

The aim of this study is to validate an integrated air monitoring approach for assessing airborne formaldehyde (FA) in the workplace. An active sampling by silica gel impregnated with 2,4-dinitrophenylhydrazine, a passive solid phase microextraction technique using O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine as on-fiber derivatization reagent, an electrochemical direct-reading monitor, and an enzyme-based badge were evaluated and tested over a range of 0.020-5.12 ppm, using dynamically generated FA air concentrations. Simple linear regression analysis showed the four methods were suitable for evaluating airborne FA. Personal and area samplings in 12 anatomy pathology departments showed that the international occupational exposure limits in the GESTIS database were frequently exceeded. This monitoring approach would allow a fast, easy-to-use, and economical evaluation of both current work practices and eventual changes made to reduce FA vapor concentrations.

• 한국인터넷방송통신학회논문지
• /
• 제21권3호
• /
• pp.73-79
• /
• 2021

4차 산업 혁명의 물결 속에서 스마트팩토리는 많은 공장에서 요구되고 있다. 하지만, 중소/중견 기업에서는 여전히 노후화된 설비를 보유하고 있어 스마트팩토리의 기초가 되는 데이터 수집 단계에서 어려움을 겪고 있다. 이 연구는 기존 설비의 개조 필요 없이, 설비 제어판의 이미지로부터 데이터를 추출하는 오픈 소스 기반의 기술을 활용 함으로써, 저비용으로 설비 모니터링하는 방법을 제안한다. 제안된 방법은 프로토타핑을 통해 자동차 부품 제조 공장의 단조 설비를 대상으로 테스트하고 평가되었다. 평가 결과 저가형 설비 모니터링이 가능함을 확인하였으며, 중소/중견 기업이 스마트팩토리를 구축하는 데 도움을 줄 것이다.

• Smart Structures and Systems
• /
• 제30권5호
• /
• pp.513-520
• /
• 2022

During the long-time service of a bolt, its preload may suffer slight perturbations or significant reductions. It is a dilemma to monitor preload changes at high resolution and full scale. Approaches for bolt preload monitoring with multi-resolution should be developed. In this paper, a simple and effective multi-resolution bolt preload monitoring approach using ultrasonic guided waves (UGW) is proposed. A linear relationship between the time-of-flight (TOF) variation of multi-reflected waves and preload is derived to theoretically reveal the multi-resolution properties of UGW. The variations of TOF before and after the slight preload perturbations are extracted by using a global evaluation method. Experimental results show that the signal-to-noise ratio (SNR) of the 1^st, 2^nd, and 3^rd-reflected UGWs is larger than 20 dB. The resolution of the 2^nd-reflected UGW is higher than that of the 1^st-reflected UGW and lower than that of the 3^rd-reflected UGW. The ultimate detectable resolutions of bolt preload (DRBP) of the 1^st and 3^th-reflected UGWs are 0.9% and 0.5%, respectively. By using the 1^st and 3^th-reflected guided waves, the bolt looseness with different degrees can be monitored simultaneously.

• 한국전통조경학회지
• /
• 제35권3호
• /
• pp.94-104
• /
• 2017

본 연구는 문화재청이 2016년도에 지역문화재 활용사업으로 추진하는 살아 숨 쉬는 향교 서원문화재 만들기 사업의 예산지원을 받은 전국 77개 향교 서원문화재 활용 사업을 대상으로 문화재 활용에 대한 이해를 갖고 있는 전문 인력을 중심으로 전문가 현장평가 및 컨설팅과 일반인 모니터링 그리고 관람객 만족도 조사를 진행하였다. 이에 사업의 계획 운영 실적 성과 연차별 특별지표 부문에 종합평가는 모두 양호 수준으로 나타났다. 사업의 종합적인 성과 중 우수한 점으로는 첫째, 지역의 문화재 향유권 신장, 둘째, 지역 내 문화재 활용 인적 네트워크 확대, 셋째, 지역 내 커뮤니티 공간으로 활용, 넷째, 자유학기제 연계 사업을 통한 문화재 활용 교육콘텐츠의 다양화 등이 있었다. 반면 미흡한 점으로는 첫째, 프로그램 품질 저하, 둘째, 사업계획 대비 실행 부족, 셋째, 지자체의 관심 및 참여 미흡, 넷째, 홍보부족, 다섯째, 자유학기제의 경우 지역 문화재 특성이 반영된 교육콘텐츠 부족 등이 있었다. 사업의 발전 방안으로는 첫째, 향교 서원문화재의 특성을 살린 프로그램 개발, 둘째, 외국인 대상 프로그램 개발, 셋째, 전문 인력 양성, 넷째, 홍보 확대, 다섯째, 새로운 강의 기법 개발, 여섯째, 지역 내 열린 공간으로 활용, 일곱째, 공간별 활용 계획, 여덟째, 평가제도 개선, 아홉째, 관람객 의견 반영 강화, 열 번째, 사업별 집중 컨설팅을 제안하였다.

• Tuberculosis and Respiratory Diseases
• /
• 제83권3호
• /
• pp.218-227
• /
• 2020

Background: The national Public-Private Mix (PPM) tuberculosis (TB) control project provides for the comprehensive management of TB patients at private hospitals in South Korea. Surveillance and monitoring of TB under the PPM project are essential toward achieving TB elimination goals. Methods: TB is a nationally notifiable disease in South Korea and is monitored using the surveillance system. The Korea Centers for Disease Control and Prevention quarterly generates monitoring indicators for TB management, used to evaluate activities of the PPM hospitals by the central steering committee of the national PPM TB control project. Based on the notification date, TB patients at PPM hospitals were enrolled in each quarter, forming a cohort, and followed up for at least 12 months to identify treatment outcomes. This report analyzed the dataset of cohorts the first quarter of 2016 through the fourth quarter of 2017. Results: The coverage of sputum, smear, and culture tests among the pulmonary TB cases were 92.8% and 91.5%, respectively. The percentage of positive sputum smear and culture test results were 30.7% and 61.5%, respectively. The coverage of drug susceptibility tests among the culture-confirmed cases was 92.8%. The treatment success rate among the smear-positive drug-susceptible cases was 83.2%. The coverage of latent TB infection treatment among the childhood TB contacts was significantly higher than that among the adult contacts (85.6% vs. 56.0%, p=0.001). Conclusion: This is the first official report to analyze monitoring indicators, describing the current status of the national PPM TB control project. To sustain its effect, strengthening the monitoring and evaluation systems is essential.

• Toxicological Research
• /
• 제31권3호
• /
• pp.221-226
• /
• 2015

With the diversification and internationalization of the food industry and the increased focus on health from a majority of consumers, food safety policies are being implemented based on scientific evidence. Risk analysis represents the most useful scientific approach for making food safety decisions. Total diet study (TDS) is often used as a risk assessment tool to evaluate exposure to hazardous elements. Many countries perform TDSs to screen for chemicals in foods and analyze exposure trends to hazardous elements. TDSs differ from traditional food monitoring in two major aspects: chemicals are analyzed in food in the form in which it will be consumed and it is cost-effective in analyzing composite samples after processing multiple ingredients together. In Korea, TDSs have been conducted to estimate dietary intakes of heavy metals, pesticides, mycotoxins, persistent organic pollutants, and processing contaminants. TDSs need to be carried out periodically to ensure food safety.