• Journal of The Korean Association For Science Education
• /
• v.24 no.5
• /
• pp.814-824
• /
• 2004

This article presents the effects of estimation activities related to speed and density on students' concept-understanding, answer-prediction, and answer-calculation in problem solving procedure with quantitative and qualitative methods. Participants were one hundred and ninety two seventh graders from one coeducational school in Seoul. Half of them participated in the estimation activities and the other half did in the measurement activities. Discussions of three students during estimation activities on density and their post-interviews were tape-recorded. Pre- and post-assessment scores were analyzed for the whole classes, and students' discussions and interviews served this research as evidences for the case analysis. Results of scores indicated that students in the estimation activities were significantly better than those in the measurement activities for predicting answers, but not for understanding concepts. Analysis of the cases revealed that estimation activity helped them to understand the relations of mass, volume and density, empirically, which enhanced their prediction ability. Furthermore, the ability could help a student with low calculation ability to comprehend the calculation problems. Thus, it is concluded that estimation activities could influence students' empirical learning on quantitative concepts, which enhanced their prediction ability.

• IE interfaces
• /
• v.17 no.spc
• /
• pp.122-130
• /
• 2004

Since the cost of software maintenance occupies about 50~75% in a general successful organization, the software maintenance plays an important role in software life cycle. In particular, if the managed system needs to be operated in a long term or the system is very large and complex, then the maintenance is especially more important. Software maintenance is defined as software modification activities after customer delivery, such as improvement of performance or functionality, error correction, adaptation to environmental changes, etc. In this paper, software cost estimation models are proposed, that is based on productivity of manpower in maintenance projects. In order to do this, the activities of maintenance are classified into function change, non-function change, user support and application operation. The proposed models are constructed and verified based on the real size and cost information of projects in the real world. The approach in this paper is to discriminate the heterogeneous activities in maintenance projects, and then to calculate the respective cost of each discriminated activity. By using the proposed models, the total cost of maintenance project is summed from the costs of four activities. In addition the number of conflicts between owner and order receiver about the amount of cost will be reduced and the reasonable cost estimation system will be established.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.21 no.3
• /
• pp.303-313
• /
• 2023

Spent fuels (SFs) are stored in a storage pool after discharge from nuclear power plants. They can be transferred to for the further processes such as dry storage sites, processing plants, or disposal sites. One of important measures of SF is the burnup. Since the radioactivity of SF is strongly dependent on its burnup, the burnup of SF should be well estimated for the safe management, storage, and final disposal. Published papers about the methodology for the burnup estimation from the known activities of important radioactive sources are somewhat rare. In this study, we analyzed the dependency of the burnup on the important radiation source activities using ORIGEN-ARP, and suggested simple correlations that relate the burnup and the important source activities directly. A burnup estimation equation is suggested for PWR fuels relating burnup with total neutron source intensity (TNSI), initial enrichment, and cooling time. And three burnup estimation equations for major gamma sources, ¹³⁷Cs, ¹³⁴Cs, and ¹⁵⁴Eu are also suggested.

• Journal of Korean Academy of Nursing Administration
• /
• v.5 no.3
• /
• pp.547-561
• /
• 1999

The purpose of this study was to determine which nursing activities are performed for patients in each of the nine KDRGs and to examine common nursing activities between patients with the nine KDRGs and special nursing activities which were not common to patients with the nine KDRGs. The study will provide basic data for estimation of nursing fees. The nine KDRGs in model project are Lens procedures, tonsillectomy, &/or adenoidectomy, appendectomy &/or not complicate principal diagnosis, vaginal delivery, cesarean section, anal & stomal procedures, inguinal & femoral hernia, uterine & adneza procedure for nonmalignancy, and simple pneumonia & pleurisy. To determine the nursing activities for each of the nine KDRG, checklists of nursing activities in each nine KDRG were developed from the literature and a total of 115 records of patients 'who were diagnosed and discharged between January and April, 1999 from a tertiary medical center. Nursing activities for each of the nine KDRG were verified through two consecutive content analyses. The results of study are followed as: 1. The checklists of nursing activities developed included direct and indirect nursing activities, for a total of 241 nursing activities. Direct nursing consisted of physical, educational, emotional-socioecomomic-spiritual nursing in 17 areas. Indirect nursing had four areas. 2. Through the two consecutive content analyses, 197 nursing activities were selected, having item CVIs of .83 or more. Those included 81 nursing activities for Lens procedures, 95 for Tonsillectomy &/or Adenoidectomy. 93 in Appendectomy &/or not complicated principal diagnosis, 155 for vaginal delivery, 172 for cesarean section, 89 for anal & stomal procedures, 93 for inguinal & femoral hernia, 108 for uterine & adneza procedures for non-malignancy, and 68 for simple pneumonia & pleurisy. 3. Nursing activities for each of the nine KDRG were compared. Activities with 80% or higher commonality within the nine KDRGs consisted of 86 of 197 nursing activities for the total designated common nursing activities, 30 common nursing activities for patients in the operation group, 45 common activities for patients in the delivery Group. Special nursing activities not common within the nine KDRGs were : 3 for Lens procedures, 1 for Tonsillectomy &/or Adenoidectomy. 2 for Appendectomy &/or not complicated principal diagnosis, 27 for vaginal delivery, 21 for Cesarean section, 6 for anal & stomal procedures, 3 for inguinal & femoral hernia, 16 for uterine & adneza procedure for non-malignancy, 8 for simple pneumonia & pleurisy. In this study, nursing activities for each of the nine KDRGs verified through two consecutive content analyses are those that are performed in the hospital. And, nursing activities for each of the nine KDRGs included all nursing activities from hospital admission to discharge. So. the checklists consisted of nursing activities that allow for an estimation of nursing fees under PPS. The classification of nursing activities in the study will provide a reference for the development of a nursing activity classification.

• Journal of the Korea Institute of Building Construction
• /
• v.4 no.4
• /
• pp.117-126
• /
• 2004

Construction industry is faced with the problems such as the quickly changeable circumstance and increasing construction companies due to regulation mollification of company registration. In order to overcome these problems, new estimation system based on historical estimation cost is ready to introduce by government step by step. But the time of transition for estimation system causes another problems such as chaos addition to simultaneity of a standard of estimation system and new estimation system, lack of related regulation, accumulation of historical extensive cost data, and adjustment methodology when historical estimation data is applied to next projects. The purpose of this study is to suggest the change factors by activities for estimating historical cost for apartment housing projects. New estimation system is based on historical construction data. For application of this system, the standard adjustment methodology system is necessary. and extensive cost data should be accumulated under an unified construction work classification system. Therefore in this study, according to the construction work classification system, every apartment housing project was classified to 16 work classifications, and 7 major composed items which occupy more than 85% of construction costs are analyzed by detailed activities and by average ratio and maximum ratio each of them. In the result of the study, furniture work, foundation work and masonry work are the works which have big gap of costs between average ration and maximum ratio. In addition to suggestion of change factor by work species, 5 qualified construction specialists are interviewed and change factors in 7 major works are analyzed.

• Korean Journal of Child Studies
• /
• v.30 no.1
• /
• pp.109-125
• /
• 2009

This study examined the effects of estimation activities on children's operation and measurement abilities. Subjects were 60 five-year-old children. This experiment used the untreated control group design with pretest and posttest. Instruments used to collect data were the Number and Operation and Measurement tests part of the Test of Mathematics Ability for Young Children (TMAYC) developed by Hong, Lee and Chung (2006). ANCOVA was employed for statistical analysis. Results of the posttest showed that children in the experimental group scored significantly higher on children's operation and measurement abilities than the control group. Results imply that an estimation program can be an effective teaching model for improving children's operation and measurement abilities.

• Biomedical Science Letters
• /
• v.12 no.4
• /
• pp.439-442
• /
• 2006

To evaluate the postmortem changes in activities of oxygen free radical metabolizing enzymes, the rats were sacrificed with cervical dislocation and were kept in an incubator at $25^{\circ}C$, 70% of humidity for 12 hours. The activities of aniline hydroxylase, catalase, glutathione-S-transferase and superoxlde dismutase were decreased with the time. On the other hand, the activity and type conversion ratio (type D ${\to}$type O) of hepatic xanthine oxidase (XO) were gradually increased. From these changes of XO, the estimation of death time (mathematical equation) could be determined with the least square method. To clarify the cause of increasing XO activity, enzyme kinetics were examined. The Km values of XO were decreased with the time. In conclusion, the determination of liver XO activity might be used for the estimation of death time in the early postmortem period.

• Journal of The Korean Digital Architecture Interior Association
• /
• v.3 no.1
• /
• pp.15-22
• /
• 2003

The purpose of this study was to analyze basic conditions for the demand estimation erection of lifetime sports facilities. This is described the whole concept of lifetime sports(sport for all) for helping the understanding of its concept correctly. Firstly, second chapter was examined the significance, function and role of lifetime sports in modern society. Secondly, third and forth chapter was examined demand and participation of lifetime sports activities for demand estimation of lifetime sports facilities. Participation rate is on the rise by the increase in income and leisure time to some extent, but after that it stops rising. In other words, the same participation rate persists without additional increase in participation by the changes in time deepening and in the patterns of demand for lifetime sports activities.

• Journal of Korean Society of Rural Planning
• /
• v.12 no.4 s.33
• /
• pp.23-32
• /
• 2006

Recently, Owing to booming of leisure activities and national enforcement of 5-day workweek system, Korean government has been promoting rural tourism policy of which operating project's title is Green Rural Experience Village, Rural Traditional Theme Village, etc. In this study, ken investigation result on Green Rural Experience Village sites, an estimation model of returns by green-tourism activities was developed. The model was constructed through factor analysis and regression analysis method. Regression model developed can estimate green-tourism revenue by investment budget, homepage preengagement sales, homepage visitors, capacity of eating and drinking facilities, capacity of lodging facilities. The model developed was applied in sample villages. With these results, estimation revenue was recorded average 138.3% of survey revenue, and statistical significance was good(correlation coefficient $R^2$ = 0.8255, level of significance : 0.000), and the range of relative error was recorded largely from -7.1% to 158.6%, and average relative error was 38.3% and good. And, the model developed in this study have the critical point in aspects of insufficient data, but the results will be used in green-tourism policies and projects, and revenue estimation about each village in the present and future is limited, but in province or the whole country the application is good.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.30 no.3
• /
• pp.137-149
• /
• 2005

This study proposes a framework enhancing the accuracy of estimation for project duration by combining linear Bayesian updating scheme with the learning curve effect. Activities in a particular project might share resources in various forms and might be affected by risk factors such as weather Statistical dependence stemming from such resource or risk sharing might help us learn about the duration of upcoming activities in the Bayesian model. We illustrate, using a Monte Carlo simulation, that for partially repetitive projects a higher degree of statistical dependence among activity duration results in more variation in estimating the project duration in total, although more accurate forecasting Is achievable for the duration of an individual activity.