• Title/Summary/Keyword: Sampling planning

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A Study on the Performance Certification System of Inspection and Diagnostic Equipment for Infrastructure using Advanced Technologies (첨단기술을 이용한 시설물 점검 및 진단장비 성능인증체계에 대한 연구)

  • Hong, Sung-Ho;Kim, Jung-Gon;Cho, Jae-Young;Kim, Do-Hyoung;Kim, Jung-Yeol;Kim, Young-Min;Lee, Dong-Wook
    • Journal of the Society of Disaster Information
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    • v.17 no.1
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    • pp.97-111
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    • 2021
  • Purpose: It is expected that various infrastructures diagnosis equipment will be needed as infrastructures management is strengthened to implement the Framework Act on Sustainable Infrastructure Management. It is necessary for a certification system to supply certified products of a reasonable level in accordance with market requirements for various convergence equipment. This paper deals with the introduction of certification system of inspection and diagnosis equipment for infrastructure using advanced technologies. Method: The basic elements, systems and procedures of certification system were reviewed through analyzing and comparing the existing similar certification system in Korea. In addition, a survey was conducted on a catalog method and the minimum performance criterion (sampling survey and complete enumeration survey) to equipment developers (manufacturers), clients and equipment users. Result: This survey showed that clients preferred complete enumeration method on the basis of minimum performance, and equipment users also preferred complete enumeration survey and sample survey, for minimum performance, at a similar rate. On the other hand, equipment developers preferred the catalog method. Conclusion: Clients and users who are the users of the diagnostic equipment preferred the minimum performance criterion because their trust in quality is important. On the other hand, developers(manufacturers) preferred the catalog method which adopts self certification because it is regulated in developing various products. There is no specific plan for the minimum performance standards required for the introduction of the method which users demand, at present. In addition, it is not desirable to force to introduce a certification system because it requires a considerable period of study to prepare the specific standards. Therefore, it is appropriate to operate the system for a certain period of time centering around the catalog method for the stable and continuous development of the infrastructure diagnosis and test equipment market in Korea. Also, it is effective to expand and develop the certification system to the extent that it minimizes the impact on the market when specific plans for the standards are prepared in the future.

Comparative Analysis of Community Health Practitioner's Activities and Primary Health Post Management Before and After Officialization of Community Health practitioner (보건진료원의 정규직화 전과 후의 보건진료원 활동 및 보건진료소 관리운영체계의 비교 분석)

  • Yun, Suk-Ok;Jung, Moon-Sook
    • Journal of agricultural medicine and community health
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    • v.19 no.2
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    • pp.141-158
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    • 1994
  • To provide better health care services to the rural population, the government has made the Community Health Practitioner(CHP) a regular government official from April 1, 1992. This study was carried out to study the impact of officialization of CHP on the activities and management system of Primary Health Post(PHP). Fifty PHPs were selected by two stage sampling, cluster and simple random, from 595 PHPs in Kyungnam and Kyungpook provinces. Data were collected by a personal interview with CHPs and review of records and reports kept in the PHPs. The study was done for the periods of January 1-March 31, 1992 (before officialization) and January 1-March 31, 1993 (after officialization). Ninety-six percent of the CHPs wanted to become a regular government official in the hope of better job security and higher salary. The proportion of CHPs who were proud of their iob was increased from 24% to 46% after officialization. Those CHPs who felt insecure for their job decreased from 30% to 10%. Monthly salary was increased by 34% from 802,600 Won to 1,076,000 Won and 90% of the CHPs were satisfied with their salary, also more CHPs responded that they have autonomy in their work planning, implementation of plan, management of the post, and evaluation of their activity. There were no appreciable changes in such CHPs' activities as assessment of local health resources, drawing map for the catchment area, utilization of community organization, grasping the current population structure in the catchment area, keeping the family health records, individual and group health education, and school health service. However, the number of home visits was increased from 13.6 times on the average per month per CHP to 27.5 times. More mothers and children were referred to other medical facilities for the immunization and family planning services. Average number of patients of hypertension, cancer, and diabetes in three months period was decreased from 12.7 to 11.6, from 1.5 to 1.2, and 4.3 to 3.4, respectively. Records for the patient care, drug management, and equipment were well kept but not for other records. The level of record keeping was not changed after officialization. The proportion of PHPs which had support from the health center was increased for drug supply from 14.0% to 30.0%, for consumable commodities from 22.0% to 52.0%, for maintenance of PHP from 54.0% to 68.0%, for supply of health education materials from 34.0% to 44.0%, and supply of equipment from 54.0% to 58.0%. Total monthly revenue of a PHP was increased by about 50,000 Won; increased by 22,000 Won in patient care and 34,700 Won in the government subsidy but decreased in the membership due and donation. However, there was no remarkable changes in the expenditure. The proportion of PHPs which had received official notes from the health center for the purpose of guidance and supervision of the CHPs was increased from 20% to 38% during three months period and the average number of telephone call for supervision from the health center per PHP was increased from 1.8 to 2.1 times(p<0.01). However, the proportion of PHPs that had supervisory visit and conference was reduced from 79% to 62%, and from 88% to 74%, respectively. The proportion of CHPs who maintained a cooperative relationship with Myun Health Workers was reduced from 42% to 36%, that with the director of health center from 46% to 24%, that with the chief of public health administration section from 56% to 36%, and that with the chairman of PHP management council from 62% to 38%. Most of the CHPs (92% before and 82% after officialization) stated that the PHP management council is not helpful for the PHP. CHPs who considered the PHP management council unnecessary increased from 4% to 16%(p<0.05). Suggestions made by the CHPs for the improvement of CHP program included emphasis on health education, assurance of autonomy for PHP management, increase of the kind of drugs that can be dispensed by CHPs, and appointment of an experienced CHP in the health center as the supervisor of CHPs. The results of this study revealed that the role and function of CHPs as reflected in their activities have not been changed after officialization. However, satisfaction in job security and salary was improved as well as the autonomy. Support of health center to the PHP was improved but more official notes were sent to the PHPs which required the CHPs more paper works. Number of telephone calls for supervision was increased but there was little administrative and technical guidance for the CHP activities.

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DEVELOPMENT OF STATEWIDE TRUCK TRAFFIC FORECASTING METHOD BY USING LIMITED O-D SURVEY DATA (한정된 O-D조사자료를 이용한 주 전체의 트럭교통예측방법 개발)

  • 박만배
    • Proceedings of the KOR-KST Conference
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    • 1995.02a
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    • pp.101-113
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    • 1995
  • The objective of this research is to test the feasibility of developing a statewide truck traffic forecasting methodology for Wisconsin by using Origin-Destination surveys, traffic counts, classification counts, and other data that are routinely collected by the Wisconsin Department of Transportation (WisDOT). Development of a feasible model will permit estimation of future truck traffic for every major link in the network. This will provide the basis for improved estimation of future pavement deterioration. Pavement damage rises exponentially as axle weight increases, and trucks are responsible for most of the traffic-induced damage to pavement. Consequently, forecasts of truck traffic are critical to pavement management systems. The pavement Management Decision Supporting System (PMDSS) prepared by WisDOT in May 1990 combines pavement inventory and performance data with a knowledge base consisting of rules for evaluation, problem identification and rehabilitation recommendation. Without a r.easonable truck traffic forecasting methodology, PMDSS is not able to project pavement performance trends in order to make assessment and recommendations in the future years. However, none of WisDOT's existing forecasting methodologies has been designed specifically for predicting truck movements on a statewide highway network. For this research, the Origin-Destination survey data avaiiable from WisDOT, including two stateline areas, one county, and five cities, are analyzed and the zone-to'||'&'||'not;zone truck trip tables are developed. The resulting Origin-Destination Trip Length Frequency (00 TLF) distributions by trip type are applied to the Gravity Model (GM) for comparison with comparable TLFs from the GM. The gravity model is calibrated to obtain friction factor curves for the three trip types, Internal-Internal (I-I), Internal-External (I-E), and External-External (E-E). ~oth "macro-scale" calibration and "micro-scale" calibration are performed. The comparison of the statewide GM TLF with the 00 TLF for the macro-scale calibration does not provide suitable results because the available 00 survey data do not represent an unbiased sample of statewide truck trips. For the "micro-scale" calibration, "partial" GM trip tables that correspond to the 00 survey trip tables are extracted from the full statewide GM trip table. These "partial" GM trip tables are then merged and a partial GM TLF is created. The GM friction factor curves are adjusted until the partial GM TLF matches the 00 TLF. Three friction factor curves, one for each trip type, resulting from the micro-scale calibration produce a reasonable GM truck trip model. A key methodological issue for GM. calibration involves the use of multiple friction factor curves versus a single friction factor curve for each trip type in order to estimate truck trips with reasonable accuracy. A single friction factor curve for each of the three trip types was found to reproduce the 00 TLFs from the calibration data base. Given the very limited trip generation data available for this research, additional refinement of the gravity model using multiple mction factor curves for each trip type was not warranted. In the traditional urban transportation planning studies, the zonal trip productions and attractions and region-wide OD TLFs are available. However, for this research, the information available for the development .of the GM model is limited to Ground Counts (GC) and a limited set ofOD TLFs. The GM is calibrated using the limited OD data, but the OD data are not adequate to obtain good estimates of truck trip productions and attractions .. Consequently, zonal productions and attractions are estimated using zonal population as a first approximation. Then, Selected Link based (SELINK) analyses are used to adjust the productions and attractions and possibly recalibrate the GM. The SELINK adjustment process involves identifying the origins and destinations of all truck trips that are assigned to a specified "selected link" as the result of a standard traffic assignment. A link adjustment factor is computed as the ratio of the actual volume for the link (ground count) to the total assigned volume. This link adjustment factor is then applied to all of the origin and destination zones of the trips using that "selected link". Selected link based analyses are conducted by using both 16 selected links and 32 selected links. The result of SELINK analysis by u~ing 32 selected links provides the least %RMSE in the screenline volume analysis. In addition, the stability of the GM truck estimating model is preserved by using 32 selected links with three SELINK adjustments, that is, the GM remains calibrated despite substantial changes in the input productions and attractions. The coverage of zones provided by 32 selected links is satisfactory. Increasing the number of repetitions beyond four is not reasonable because the stability of GM model in reproducing the OD TLF reaches its limits. The total volume of truck traffic captured by 32 selected links is 107% of total trip productions. But more importantly, ~ELINK adjustment factors for all of the zones can be computed. Evaluation of the travel demand model resulting from the SELINK adjustments is conducted by using screenline volume analysis, functional class and route specific volume analysis, area specific volume analysis, production and attraction analysis, and Vehicle Miles of Travel (VMT) analysis. Screenline volume analysis by using four screenlines with 28 check points are used for evaluation of the adequacy of the overall model. The total trucks crossing the screenlines are compared to the ground count totals. L V/GC ratios of 0.958 by using 32 selected links and 1.001 by using 16 selected links are obtained. The %RM:SE for the four screenlines is inversely proportional to the average ground count totals by screenline .. The magnitude of %RM:SE for the four screenlines resulting from the fourth and last GM run by using 32 and 16 selected links is 22% and 31 % respectively. These results are similar to the overall %RMSE achieved for the 32 and 16 selected links themselves of 19% and 33% respectively. This implies that the SELINICanalysis results are reasonable for all sections of the state.Functional class and route specific volume analysis is possible by using the available 154 classification count check points. The truck traffic crossing the Interstate highways (ISH) with 37 check points, the US highways (USH) with 50 check points, and the State highways (STH) with 67 check points is compared to the actual ground count totals. The magnitude of the overall link volume to ground count ratio by route does not provide any specific pattern of over or underestimate. However, the %R11SE for the ISH shows the least value while that for the STH shows the largest value. This pattern is consistent with the screenline analysis and the overall relationship between %RMSE and ground count volume groups. Area specific volume analysis provides another broad statewide measure of the performance of the overall model. The truck traffic in the North area with 26 check points, the West area with 36 check points, the East area with 29 check points, and the South area with 64 check points are compared to the actual ground count totals. The four areas show similar results. No specific patterns in the L V/GC ratio by area are found. In addition, the %RMSE is computed for each of the four areas. The %RMSEs for the North, West, East, and South areas are 92%, 49%, 27%, and 35% respectively, whereas, the average ground counts are 481, 1383, 1532, and 3154 respectively. As for the screenline and volume range analyses, the %RMSE is inversely related to average link volume. 'The SELINK adjustments of productions and attractions resulted in a very substantial reduction in the total in-state zonal productions and attractions. The initial in-state zonal trip generation model can now be revised with a new trip production's trip rate (total adjusted productions/total population) and a new trip attraction's trip rate. Revised zonal production and attraction adjustment factors can then be developed that only reflect the impact of the SELINK adjustments that cause mcreases or , decreases from the revised zonal estimate of productions and attractions. Analysis of the revised production adjustment factors is conducted by plotting the factors on the state map. The east area of the state including the counties of Brown, Outagamie, Shawano, Wmnebago, Fond du Lac, Marathon shows comparatively large values of the revised adjustment factors. Overall, both small and large values of the revised adjustment factors are scattered around Wisconsin. This suggests that more independent variables beyond just 226; population are needed for the development of the heavy truck trip generation model. More independent variables including zonal employment data (office employees and manufacturing employees) by industry type, zonal private trucks 226; owned and zonal income data which are not available currently should be considered. A plot of frequency distribution of the in-state zones as a function of the revised production and attraction adjustment factors shows the overall " adjustment resulting from the SELINK analysis process. Overall, the revised SELINK adjustments show that the productions for many zones are reduced by, a factor of 0.5 to 0.8 while the productions for ~ relatively few zones are increased by factors from 1.1 to 4 with most of the factors in the 3.0 range. No obvious explanation for the frequency distribution could be found. The revised SELINK adjustments overall appear to be reasonable. The heavy truck VMT analysis is conducted by comparing the 1990 heavy truck VMT that is forecasted by the GM truck forecasting model, 2.975 billions, with the WisDOT computed data. This gives an estimate that is 18.3% less than the WisDOT computation of 3.642 billions of VMT. The WisDOT estimates are based on the sampling the link volumes for USH, 8TH, and CTH. This implies potential error in sampling the average link volume. The WisDOT estimate of heavy truck VMT cannot be tabulated by the three trip types, I-I, I-E ('||'&'||'pound;-I), and E-E. In contrast, the GM forecasting model shows that the proportion ofE-E VMT out of total VMT is 21.24%. In addition, tabulation of heavy truck VMT by route functional class shows that the proportion of truck traffic traversing the freeways and expressways is 76.5%. Only 14.1% of total freeway truck traffic is I-I trips, while 80% of total collector truck traffic is I-I trips. This implies that freeways are traversed mainly by I-E and E-E truck traffic while collectors are used mainly by I-I truck traffic. Other tabulations such as average heavy truck speed by trip type, average travel distance by trip type and the VMT distribution by trip type, route functional class and travel speed are useful information for highway planners to understand the characteristics of statewide heavy truck trip patternS. Heavy truck volumes for the target year 2010 are forecasted by using the GM truck forecasting model. Four scenarios are used. Fo~ better forecasting, ground count- based segment adjustment factors are developed and applied. ISH 90 '||'&'||' 94 and USH 41 are used as example routes. The forecasting results by using the ground count-based segment adjustment factors are satisfactory for long range planning purposes, but additional ground counts would be useful for USH 41. Sensitivity analysis provides estimates of the impacts of the alternative growth rates including information about changes in the trip types using key routes. The network'||'&'||'not;based GMcan easily model scenarios with different rates of growth in rural versus . . urban areas, small versus large cities, and in-state zones versus external stations. cities, and in-state zones versus external stations.

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