• Journal of Industrial Technology
• /
• v.28 no.B
• /
• pp.157-165
• /
• 2008

Level II AFDA and Level III MCS reliability models are applied to analyze the stability of armor units on trading and coastal harbors in Korea. Hudson's formula and Van der Meer's formula are used in this reliability analysis. Also, probability density functions of reliability index and probability of failure are derived by the additional analysis. In addition, the partial safety factors of all harbors related to armor units can be straightforwardly evaluated by the inverse-reliability method. The upper and lower limits and average level of partial safety factors can be statistically investigated with the results of all cases applied in this paper. Therefore, it may be possible to design armor units of new breakwaters including the uncertainty of random variable and target level by using the present results.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.38 no.1
• /
• pp.124-130
• /
• 2015

In many inventory situations, items for sales are generally stocked in a multiple of variations called stockkeeping units, such as size, color, style, and so on. For better management performance on sales items, proper and effective management is necessary for the stockkeeping units. In dealing with many items and those stockkeeping units, individual inventory analysis for each stockkeeping unit needs large amount of time or cost. Also the individual approach in inventory planning increases the demand variation of an item as the result by combining of demand variations of all stockkeeping units, accordingly the inventory turnover ratio and profitability are dropped down. This research suggests an effective method of systematic control of total stockkeeping units by generating from the total item basis, and shows how to reduce the safety stock and the average inventory with attaining a planned customer fill rate of the item and each stockkeeping units.

• Journal of Industrial Technology
• /
• v.21 no.B
• /
• pp.163-174
• /
• 2001

A dynamic reliability model for analyzing the stability of armor units on rubble-mound breakwater is mathematically developed by using Hudson's formula and definition of single-failure mode. The probability density functions of resistance and loading functions are defined properly, the related parameters to those probability density functions are also estimated straightforwardly by the first-order analysis. It is found that probabilities of failure for the stability of armor units on rubble-mound breakwater are continuously increased as the service periods are elapsed, because of the occurrence of repeated loading of random magnitude by which the resistance may be deteriorated. In particular, the factor of safety is incorporated into the dynamic reliability model in order to evaluate the probability of failure as a function of factor of safety. It may thus be possible to take some informations for optimal design as well as managements and repairs of armor units on rubble-mound breakwater from the dynamic reliability analyses.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.15 no.2
• /
• pp.86-96
• /
• 2003

A fracture or breakage of the concrete armor units in the primary cover layer of breakwaters is studied by using the reliability analysis which may be defined as the structural stability. The reliability function can be derived as a function of the angle of rotation that represents the rocking of armor units quantitatively. The relative influences of all of random variables related to the material and geometric properties on the fracture of armor units is analyzed in detail. In addition, the probability of failure for the fracture of individual armor unit can be evaluated as a function of the incident wave height. Finally, Bernoulli random process and the allowable fracture ratio may be introduced together in this paper, by which the probability of failure of a breakwater due to the fracture of armer units can be obtained straightforwardly. It is found that the probability of failure of a breakwater due to the fracture of armor units may be varied with the several allowable fracture ratios. Therefore, it should be necessary to consider the structural stability as well as the hydraulic stability for the design of breakwaters with multi-leg slender concrete armor units of large size under wave action in deep water.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2003.05a
• /
• pp.47-55
• /
• 2003

Curved beams are one of the most important basic structural units as well as the beams, columns and plates. Most complicated structures consist of only these basic units and therefore it is very attractive research subject to analysis both the static and dynamic behavior of such units including the arches. The problems of free vibrations of curved beams have been the subject of much work due to their many practical applications.(an ellipsis)

• Journal of KIISE:Computing Practices and Letters
• /
• v.8 no.6
• /
• pp.765-777
• /
• 2002

For the battlefield analysis, it is required to get correct information about the identification and moving status of target enemy units. However, it is difficult for us to collect all of the information perfectly, because of the technology of communications, jamming, and tactics. Therefore, we need a reasoning function that predicts and analyzes future moving status for target units by using collected moving information and domain knowledge. Especially. since the moving units have characteristics of moving objects, which change their position and shape over time, they require functions to manage and predict locations of moving objects. Therefore, in this paper, we propose a location prediction system of moving units for battlefield analysis. The proposed system not only predicts unknown units, unidentified units, and main strike directions to application domain for battlefield analysis, but also estimates the past or future locations of moving objects not stored in a database.

• Journal of Gifted/Talented Education
• /
• v.25 no.5
• /
• pp.711-729
• /
• 2015

The purposes of this study are to derive the regions in Seoul that lack gifted education units by analyzing the spatial distribution of the units and to investigate the factors related to the unit locations. The gifted education units are divided into the three following types: the first type is a gifted class at a school, the second type is a gifted education center at a provincial office of education, and the third type is a gifted education center at a university. The results of using a GIS-based spatial analysis were as follows. First, a buffering analysis showed that even though there were gifted educational blind spots in Jongno-gu and in parts of the outskirts of Seoul, the spatial distribution of gifted education units in Seoul seemed homogeneous because they were too small. Second, a special quotient analysis showed that there was a hub unit of gifted education in Guro-gu. Third, an analysis of local Moran's Index showed that Jung-gu was a cold spot and Songa-gu was a hot spot. Fourth, a correlation analysis investigated that the number of gifted education units had generally no statistically significant relationship with economic factors. These results will help to improve the efficiency and equity of the management of the gifted education units in Seoul that will be established or expanded in the future.

• Journal of Home Health Care Nursing
• /
• v.18 no.2
• /
• pp.118-125
• /
• 2011

Purpose: The aim of this study was to evaluate the efficiency of nursing units in a hospital using DEA. Methods: Data were collected using the medical information system of a general hospital in a city. Input variables were number of nurses, number of nurse-aides, number of beds, and overhead costs. Output variables included number of admitted patients, rate of bed utilization, satisfaction of discharged patients, and prevention rate of safety accidents and sores. EMS Window version 3.1 was used to measure the efficiency score and descriptive statistics were applied to analyze the general characteristics of variables. Results: The average efficiency score of 18 general nursing units was approximately .99. Nine nursing units had a 1.00 efficiency score. Conclusion: Our findings reveal that nursing units operated very efficiently. To increase efficiency of inefficient nursing units, we recommend results of the DEA slack analysis as a benchmark of the most efficient nursing unit.

• Journal of the Architectural Institute of Korea Planning & Design
• /
• v.33 no.12
• /
• pp.53-63
• /
• 2017

The purpose of this study is to present an integrated analysis for energy use and its patterns as vertical locations of the dwelling units in apartment buildings which are located in an urban area and constructed by a renowned contractor. In order to enhance the effectiveness of the method, the original data of electricity, water, and gas bills which directly reflect the energy use are sorted and analyzed into several groups as vertical locations in each building. And also, by use of comparing and contrasting the data on a monthly and yearly basis, the accuracy of analyses for seasonal energy use and its patterns is strengthened. Comparative analyses used in this study describe the results that vertical locations of dwelling units do not have much influence on electricity and water usage, but are closely related with gas usage for a heating season. According to the analysis of gas usage, the units on the ground and right above pilotis need enhancement in the insulations for heating to mitigate energy loss. Also, the analysis for the middle floor units in each group describe the fact that the gas usage of the units on the ground is consumes 1.5 times greater than that of the typical floors. Therefore, enhanced insulation strategies need to be considered against the adverse condition that the heat loss increases as the wall facing the outside air increases or as the wind velocity increases through the pilotis.

• Journal of Agricultural Extension & Community Development
• /
• v.23 no.3
• /
• pp.285-293
• /
• 2016

The increase in demand for leisure time by the public and the vitalization of agricultural tourism resulting from the expansion of the five-day work week are expected to greatly contribute to the rural economy, but actual studies analyzing the ripple effect of the agricultural tourism industry are lacking. In order to analyze the economic ripple effect, tourism or agricultural tourism must become an independent sector in the inter-industry relations table's sector classification, but because it is not, the study uses a method of analysis which involves creating a satellite account. However, because agricultural tourism has a clear main agent in farms unlike general tourism which does not, there is one method in which provisions are made by farms or farm villages and another method in which outside products are used. The purpose of the present is to measure the economic ripple effect of agricultural tourism with a focus on 162 subclasses by applying positive data from the education sector input into agricultural tourism. Satellite accounts which considered intermediate input were created and applied to positive data, the analysis of which revealed agricultural tourism to account for 462 billion won, which is 0.01% of the total production amount of 3,503,480 billion won, while the production inducement coefficient was 3.2895 units when the final demand of agricultural tourism occurs. When the production inducement coefficient is at 3.2895 units, highest sector was agricultural tourism at 0.9968 units followed by restaurants and bars at 0.3325 units, roadt transportation services at 0.3183 units, lodging services at 0.1520 units, and petroleum products at 0.1290 units.