• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.1
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• pp.60-67
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• 2014

This paper considers an inbound ordering and outbound dispatching problem for multi-products and multi-vehicles in a third-party distribution center. The demands are dynamic over a discrete and finite time horizon, and replenishing orders are shipped in various transportation modes and the freight cost is proportional to the number of vehicles used. Any mixture of products is loaded onto any type of vehicles. The objective of the study is to simultaneously determine the inbound lot-sizes, the outbound dispatching sizes, and the types and numbers of vehicles used to minimize total costs, which consist of inventory holding cost and freight cost. Delivery time window is one of the general dispatching policies between a third-party distribution center and customers in practice. In the policy, each demand of product for a customer must be delivered within the time window without penalty cost. We derive mixed integer programming models for the dispatching policy with delivery time windows and on-time delivery dispatching policy, respectively and analyze the effect on a dispatching policy with delivery time windows by comparing with on-time delivery dispatching policy using various computational experiments.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.1
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• pp.89-93
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• 2009

In this paper, we investigated effect of sensing time on the performance of enhanced spectrum sensing method, which is the energy detector with multiples of verification using time delay, under Suzuki channel. We assumed that SNR is 1dB, $P_{FA}=0.1$ and various mobile speed such as 3, 60, 110 km/h. The performance is investigated by simulation and compared to that of conventional energy detector.

• Interaction and multiscale mechanics
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• v.5 no.3
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• pp.169-185
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• 2012

The concrete bridge is likely to produce fatigue cracks during long period of service due to the moving vehicular loads and the degeneration of materials. This paper deals with the time-frequency analysis of a coupled bridge-vehicle system. The bridge is modeled as an Euler beam with breathing cracks. The vehicle is represented by a two-axle vehicle model. The equation of motion of the coupled bridge-vehicle system is established using the finite element method, and the Newmark direct integration method is adopted to calculate the dynamic responses of the system. The effect of breathing cracks on the dynamic responses of the bridge is investigated. The time-frequency characteristics of the responses are analyzed using both the Hilbert-Huang transform and wavelet transform. The results of time-frequency analysis indicate that complicated non-linear and non-stationary features will appear due to the breathing effect of the cracks.

• Journal of the Korean Home Economics Association
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• v.32 no.3
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• pp.63-70
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• 1994

This study investigated the factors influencing married men's time allocation in child care. A multidimensional theoritical approach employing the perspectives of economic efficiency time availability and role ideology was employed to explain variations in fathers' participation in child care. In addition the effects of several socio-demographic variables were investigated. The sample was drawn from the National Survey of Families and Households (NSFH) conducted in 1987-1988 by the Center for Demography and Ecology in University of Wisconsin-Madison. Results indicated that the time availability perspective was significantly supported and the economic efficiency perspective was partially supported. On the other hand no singificant evidence was found for the effect of role ideology on fathers' child care time. Overall demographic variables had a nonsignificant effect (except in the case of age) on the amount of fathers' participation in child care.

• Korean journal of food and cookery science
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• v.11 no.2
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• pp.98-103
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• 1995

The effect of blanching time, blanching water and power settings of microwave oven on the minerals retention in spinach and broccoli were investigated. The vegetables were blanched for 60, 120 and 180 sec, with water 0ml, 50ml and 100ml every 100 g of raw material at two different power settings (700w, 400w). The retention of minerals(Ca,K,Mg,Cu,Fe,Na,p) in spinach and broccoli were higher at the 400w power than 700w power level, regardless of blanching time. At the high power, the retention of minerals in spinach and broccoli were reduced remarkably as the blanching time increased. The reason for this is that the increasing power level results in greater water coming ou from the vegetable. Also, minerals in vegetable as coming out with this water loss in proportion to the blanching time.

• IE interfaces
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• v.16 no.4
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• pp.400-410
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• 2003

Most of the demand forecasting which have been studied is about long-term time series over 15 years demand forecasting. In this paper, we set up the most optimal ARIMA model for the short-term time series demand forecasting and suggest demand forecasting system for short-term time series by appraising suitability and predictability. We are going to use the univariate ARIMA model in parallel with the bivariate transfer function model to improve the accuracy of forecasting. We also analyze the effect of advertisement cost, scale of branch stores, and number of clerk on the establishment of marketing policy by applying statistical methods. After then we are going to show you customer's needs, which are number of buying products. We have applied this method to forecast the annual sales of refrigerator in four branch stores of A company.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.49
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• pp.111-137
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• 2011

UCP 600 Article 14(b), providing rules for the period of the examination of documents, is a radical reorganization of UCP Article 13(b). The provision changes the period of time to a maximum of five banking days instead of reasonable time. One of the critical problems giving rise to the difficulty in interpretation and application is the question of fact that there may be two possible conflicting options in determining the time of checking documents presented. The one doctrine is fixed time(safe harbor) standard, and the other is hidden reasonableness standard. This study analyzes which option should be adopted for the optimal application standard by welfare effect methodology using consumer surplus approach and suggests that safe harbor standard should be optimal solution to the determination of period of examination of documents presented in letter of credit regime.

• Communications for Statistical Applications and Methods
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• v.21 no.5
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• pp.387-393
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• 2014

Recurrent gap times are analyzed with diverse methods under several assumptions such as a marginal model or a frailty model. Several resampling techniques have been recently suggested to estimate the covariate effect; however, these approaches can be applied with a time-fixed covariate. According to simulation results, these methods result in biased estimates for a time-varying covariate which is often observed in a longitudinal study. In this paper, we extend a resampling method by incorporating new weights and sampling scheme. Simulation studies are performed to compare the suggested method with previous resampling methods. The proposed method is applied to estimate the effect of an educational program on traffic conviction data where a program participation occurs in the middle of the study.

• International Journal of Industrial Entomology and Biomaterials
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• v.27 no.1
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• pp.180-184
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• 2013

Recently, silk sericin has attracted the attention of researchers owing to its useful properties as a biomaterial including 1) good wound healing and cell activities, 2) fast gelation character, and 3) high water retention property. In the present study, silk sericin was prepared using different extraction times in hot water and the effect of extraction time on the rheological properties of sericin solutions and gels was examined. It was found that the production yield of sericin increased with extraction time. The shear viscosity of sericin solutions and gels decreased with increasing extraction time due to a decrease in sericin molecular weight. When the sericin solution transformed to a gel, the viscosity increased and the shear thinning behavior was more evident. In addition, the shear stress measurements indicated that the slip between the sericin samples and the measuring plate of the rheometer was increased by the gelation of sericin. The compression strength of sericin gel could be increased remarkably (by more than 100 fold) by preparation using the freezing and thawing method.

• International Journal of Automotive Technology
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• v.1 no.2
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• pp.71-77
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• 2000

High temperature materials in service are subjected to mechanical damage due to operating load and metallurgical damage due to operating temperature. Therefore, when designing or assessing life of high temperature components, both factors must be considered. In this paper, the effect of tensile hold time on high temperature fatigue crack growth and long term prior thermal aging heat treatment on creep rupture behavior were investigated using STS 316L and STS 316 austenitic stainless steels, which are widely used for high temperature components like in automotive exhaust and piping systems. In high temperature fatigue crack growth tests using STS 316L, as tensile hold time increased, crack growth rate decreased in relatively short tensile hold time region. In long term aged specimens, cavity type microcracks have been observed at the interface of grain boundary and coarsened carbide.