• Title/Summary/Keyword: Effectiveness

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Development and Performance Test of Gas Safety Management System based on the Ubiquitous Home (u-home 가스안전관리시스템 개발 및 성능시험)

  • Park, Gyou-Tae;Lyu, Geun-Jun;Kim, Young-Gyu;Kim, Yeong-Dae;Jee, Cha-Wan;Kwon, Jong-Won;Kim, Hie-Sik
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.48 no.3
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    • pp.13-20
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    • 2011
  • In this paper, we proposed a system to raise gas safety management by using the wireless communication module and intelligent gas safety appliances. Our designed systems configure a micom-gas meter, an automatic extinguisher, sensors, and a wallpad. A micom-gas-meter monitors gas flow, gas pressure, and earthquake. An automatic fire extinguisher checks gas(combustible) leaks and temperature of $100^{\circ}C$ and $130^{\circ}C$. Sensors measure smoke and CO gas. In our novel system, a micom-gas meter cut off inner valve with warnings, an automatic fire extinguisher cut off middle valve and spray extinguishing materials, and sensors generate signals for smoke and CO when occurring gas risk. Gas safety appliances and sensors takes safety measures, and transmit those signal to a wallpad. The wallpad again transmit signal like events to a control server. Users can connect web pages for gas safety through B-ISDN and control and manage them. We hereby devised scenarios for gas safety and risk management, and demonstrated their effectiveness through experiments.

Wireless Water Leak Detection System Using Sensor Networks (센서네트워크를 이용한 무선 누수 탐지 시스템)

  • Choi, Soo-Hwan;Eom, Doo-Seop
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.48 no.3
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    • pp.125-131
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    • 2011
  • Water leak detection system is a system based on wireless sensor networks(WSNs) which detect a leak on water supply, localize the leak position and finally inform a water management center. A traditional leak detection method is to use experienced personnel who walk along a pipeline listening to the sound that is generated by the leaks and their effectiveness depend on the experience of the user. Also making more successful detection, it should be processed at middle of the night when people do not use water, as the result users have to operate the leak detection system at midnight. In this paper, we propose a new method for the water leak detection system based on the WSNs and describe it in detail. Leak detection devices which detect a leakage of water transmit and receive the result of water leak detection with each other by configuring WSNs to improve reliability of the detection result. Also, we analyzed the sound from water flowed in pipeline, proposed the pre-signal processing to separate a leakage sound from noisy sound. And lastly, It is especially important to make a time synchronization with water leak detection devices that are installed on the pipeline, we used 1PPS(1 Pulse Per Second) signal generated by GPS, therefore we could get a precise time synchronization. The proposed system set up in Namyangju and performances were evaluated.

A Study on the Influence of Flexible Work Scheme for Job-Family Connection on Job Satisfaction (일·가정 병립을 위한 유연근무제가 직무만족도에 미치는 영향)

  • Kim, Min-Sung;Lim, Sang-Ho
    • Industry Promotion Research
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    • v.3 no.2
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    • pp.33-40
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    • 2018
  • The purpose of this study is to analyze the effect of flexible working system for work - family connection on job satisfaction. A total of 73 questionnaires were analyzed for workers. The results of this study are as follows: First, flexible work system for work and home affairs has a statistically insignificant relationship with job satisfaction, flexible work system, work satisfaction, work status, flexible work system, organizational satisfaction, But the correlation between job satisfaction and organizational satisfaction showed a low correlation of .313, p <.01. Second, according to the regression analysis on the job satisfaction of the flexible work system, it was analyzed that the flexible work system for work and home affair did not have a statistically significant effect on the job satisfaction. Third, there was a significant relationship between the number of employees and average years of service. The average number of years of service was below 5 years. No child (38.4%), 1 person (15.1%), 2 children (11% ). & Lt; / RTI & gt; The purpose of this study is to examine the effect of the flexible work system on the job satisfaction of the worker and the family, and to verify the effectiveness of the flexible work system by increasing the flexible work system and the job satisfaction by activating the flexible work system.

Developing a Model to Predict Road Surface Temperature using a Heat-Balance Method, Taking into Traffic Volume (교통량을 고려한 열수지법에 의한 노면온도 예측모형의 구축)

  • Son, Young-Tae;Jeon, Jin-Suk;Whang, Jun-Mun
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.14 no.2
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    • pp.30-38
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    • 2015
  • In this study, to improve effectiveness of road management services and the safety of the road in winter, road surface temperature prediction model was developed. We have utilized the existing input data of meteorological data and additional traffic data. This Road surface temperature prediction model was utilizing a Heat-Balance Method additionally considering amount of traffic that produce heat radiation by vehicle-tire friction. This improved model was compared to the based model to check into influence of traffic affecting the road surface temperature. There were verified by comparing the real observed road surface temperature of the third Gyeong-In highway and road surface temperature from the two models. As a result, the error of real observed and the predicted value (RMSE) was found to average $1.97^{\circ}C$. Observed road surface temperature was dramatically affected by the sunlight from 6 a.m. to 2 p.m. and degree of influence decreases after that. The predictive value of the model is lower than the observed value in the afternoon, and higher at night. These results appear due to the shielding of solar radiation caused by the vehicle in the afternoon and at night, the vehicle appeared to cause thermal heat supply.

A Study on the Operation Boundary of Ramp Metering System (진입제어 전략 적용 시 적정 운영영역 설정에 관한 연구)

  • Kim, Kyu-Ok;Park, Joon-Hyeong;Park, Ji-Eun;Shin, Hee-Cheol
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.10 no.2
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    • pp.9-21
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    • 2011
  • The ramp metering strategy is one of the effective ways to solve the freeway traffic congestion in peak time periods. The study was initiated with assurance that the traffic conditions of ramp and mainline that mitigate the congestion would exist. Under the moderate traffic volume levels, ramp metering is expected to improve the quality of freeway operation. To derive a range of traffic condition, three operation strategies(Do nothing, ramp metering, minimum ramp control) were set up and the ALINEA algorithm was implemented with microscopic traffic simulator "VISSIM". The volumes of mainline and ramp are key parameters for the simulation scenarios. Measures of effectiveness for the study include mainline density and average vehicle speed. Operation boundaries in terms of traffic volume were proposed for operating ramp metering strategy. The results show that under the proposed traffic conditions the ramp metering was more successful to increase average vehicle speeds. Traffic controls under the operation boundaries of traffic levels give significant effects for density and average vehicle speed. The outcomes of this study would be useful to improve the performance of ramp metering strategies.

A Stability Test of the Regression Coefficients for the Linear Models using Chow Test (차우검정을 활용한 선형회귀모형간 유사성 검증)

  • Lee, Ki-Young;Lee, Seongkwan Mark;Jeong, So-Young;Heo, Tae-Young
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.16 no.2
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    • pp.73-82
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    • 2017
  • In this research, we tried to check the applicability of a Chow test to the linear models which are generated in the process of transportation planning or traffic flow analyses. The Chow test is a very popular statistical method which is being used to see if the coefficients from two separate linear regression models are equal or not. In order to prove the effectiveness of the Chow test, we found the linear relationships between speed and density under the situations such as driving in daytime and in nighttime on a rainy day. Based on the two months of Joong-Bu Expressway traffic data, we proved that the Chow test is useful to testify the similarity between two linear regression models. And this statistical tool seems to be able to have a very important role in traffic flow analysis or in transportation planning process. Finally, we expect the Chow test be implemented even to the non-linear regression models or to the multi-variate models.

Evaluation of Travel Time Prediction Reliability on Highway Using DSRC Data (DSRC 기반 고속도로 통행 소요시간 예측정보 신뢰성 평가)

  • Han, Daechul;Kim, Joohyon;Kim, Seoungbum
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.17 no.4
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    • pp.86-98
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    • 2018
  • Since 2015, the Korea Expressway Corporation has provided predicted travel time information, which is reproduced from DSRC systems over the extended expressway network in Korea. When it is open for public information, it helps travelers decide optimal routes while minimizing traffic congestions and travel cost. Although, sutiable evaluations to investigate the reliability of travel time forecast information have not been conducted so far. First of all, this study seeks to find out a measure of effectiveness to evaluate the reliability of travel time forecast via various literatures. Secondly, using the performance measurement, this study evaluates concurrent travel time forecast information in highway quantitatively and examines the forecast error by exploratory data analysis. It appears that most of highway lines provided reliable forecast information. However, we found significant over/under-forecast on a few links within several long lines and it turns out that such minor errors reduce overall reliability in travel time forecast of the corresponding highway lines. This study would help to build a priority for quality control of the travel time forecast information system, and highlight the importance of performing periodic and sustainable management for travel time forecast information.

Revealing the Spatial Distribution of Inorganic Elements in Rice Grains

  • Jeon, Ji Suk;Choi, Sung Hwa;Lee, Ji Yeon;Kim, Ji A;Yang, Young Mi;Song, Eun Ji;Kim, Jae Sung;Yang, Jung Seok;Kim, Kyong Su;Yoo, Jong Hyun;Kim, Hai Dong;Park, Kyung Su
    • Bulletin of the Korean Chemical Society
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    • v.35 no.11
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    • pp.3289-3293
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    • 2014
  • Femtosecond laser ablation (fs LA) was used in this study to identify pollution by heavy metals and the distribution of elemental nutrients at different rice milling ratios. Polished rice (degrees of milling of 3, 5, 7, 9, and 11) was collected from major Korean supermarkets and one sample thereof was selected. An internal quality control experiment was conducted using a rice flour certified reference material from the Korea Research Institute of Standards and Science (KRISS CRM) for the evaluation of the efficacy. To assess the effectiveness of the analysis method, the reliability was validated using a food analysis performance assessment scheme (FAPAS), with chili powder serving as an external quality control. The results of the analysis of the inorganic elements Ti, Ca, Al, Fe and Mn in white and brown rice with degrees of milling of 3, 5, 7, 9 and 11 using ICP-MS, ICP-OES and AAS revealed contents of 0.40, 49.2, 2.43, 5.36 and 10.3 mg/kg in white rice and 0.59, 78.0, 7.52, 11.0 and 18.5 mg/kg in brown rice, respectively. Among the elements, there were remarkable differences in the measured contents. By comparing the contents of the elements at different degrees of milling, Ti, Co, As, Ca, Al, Cu, Fe, and Mn were determined to be distributed on the surface of the rice grains, whereas the contents of Cd and Pb increased toward the center of the rice grains, and Si was evenly distributed. After the quantitative analysis of rice samples polished to different degrees of milling, Ca and Al, which were contained in large amounts, and Si were analyzed with specificity by fs LA. The results show that Ca and Al were distributed in the rice husk (protective covering of rice) and Si was distributed in all parts of the rice.

The Forced Motion Analyses by Using Two Dimensional 6-Node and Three Dimensional 16-Node Isoparametric Elements with Modification of Gauss Sampling Point (6절점 2차원 및 16절점 3차원 등매개변수 요소의 가우스 적분점 수정을 이용한 강제진동 해석)

  • 김정운;권영두
    • Computational Structural Engineering
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    • v.8 no.4
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    • pp.87-97
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    • 1995
  • For the same configuration of two-dimensional finite element models, 6-node element exhibits stiffer bending stiffness than 8-node element. This is true in the relation between 16-node element and 20-node element for three-dimensional model. This stiffening phenomenon comes from the elimination of several mid nodes from full-node elements. Therefore, this may be called 'relative stiffness stiffening phenomenon'. It seems that there are a couple of ways to correct the stiffening effect, however, we could find only one effective method-the method of modification of Gauss sampling points-which passes the patch test and does not alter other kinds of stiffness, such as extensional stiffness. The quantity of modification is a function of Poisson's ratios of the constituent materials. We could obtain two modification equations, one for plane stress case and the other for plane strain case. This method can be extended to 3-dimensional solid elements. Except the exact plane strain cases, most 3-dimensional plates could be modeled successfully with 16-node element modified by the equation for the plane stress case. The effectiveness of the modification method is checked by applying it to several examples with excellent improvements. In numerical examples, beams with various boundary conditions are subjected to static and time-dependent loads. Free and forced motion analyses of beams and plates are also tested. The beam and plate may be composed of isotropic multilayers as well as a single layer.

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Interaction Analysis between Tapered Sectional Launching Nose and Superstructure Section of ILM Concrete Bridge (변단면 압출추진코와 ILM 교량 상부단면의 상호작용 해석)

  • Lee Hwan-Woo;Jung Du-Hwoe;Ahn Tae-Wook
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.19 no.2 s.72
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    • pp.139-150
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    • 2006
  • ILM(incremental launching method) bridge is one of the prestressed concrete bridge construction methods widely adopted owing to its effectiveness for the quality control. The sections of the launched superstructure pass every position of the bridge spans. This launching process causes the bridge sections to be experienced in the quite different stress states with the stress state occurred after construction completely. Due to the self weight of sections, particularly, the superstructure sections(deck) experience maximum positive and negative moment as well as maximum shear force during launching process. To minimize the temporarily caused sectional forces, launching nose is generally used in the construction method. Therefore, the magnitude of this sectional forces should be checked for the safety of super structure in construction and it is dependent on the structural characteristics of launching nose. In this study, the simplified formulas to analyze the sectional force occurred by the nose-deck interaction in ILM construction are developed. The considering parameters are the span length ratio, stiffness ratio and weight ratio between the launching nose and the super structure. In particular, the developed formulas can consider the tapered sectional shape of launching nose and the diaphragm wall in the superstructure. Additionally, the sensitivity analysis is performed to analyze the effects of nose-deck interaction according to the design parameters.