• The Journal of Information Systems
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• v.18 no.2
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• pp.127-150
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• 2009

Although many employees in the logistics/small package express companies are using mobile information systems. there is little research on the individual impacts of adopting mobile information systems in the distribution area. Therefore, this study attempts to develop the research model to evaluate individual impacts on using mobile information systems which are frequently utilized in logistics and small package express companies. In order to propose the research model, we attempt to incorporate technology acceptance model and IS success model to evaluate individual impacts on using mobile information systems. To verify the research model, we collected 225 data from staffs who have mobile IT system in distribution and logistics area. We also verified the validity and reliability by using SEM(structural equation modeling). As a results, we found that system use, cognitive judgement and attitude can be the key variables to improve individual impacts by using mobile information system. We further found that perceived usefulness can be ere of the Imp factors to improve the individual impacts. Based on out findings, we can understand that this research model can provide a deeper understanding of individual impacts of mobile information systems.

• Journal of the Korean Data and Information Science Society
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• v.24 no.4
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• pp.931-940
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• 2013

For analysis of clustered survival data, the inferences of parameters in semi-parametric frailty models have been widely studied. It is also important to investigate the potential heterogeneity in event times among clusters (e.g. centers, patients). For purpose of this analysis, the interval estimation of frailty is useful. In this paper we propose a visualizing method to present confidence intervals of individual frailties across clusters using the frailtyHL R-package, which is implemented from h-likelihood methods for frailty models. The proposed method is demonstrated using two practical examples.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.2
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• pp.193-201
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• 2011

Clamp type transferring mechanism for package substrate's wet processes was newly developed instead of conventional roller type transferring mechanism. Clamp type transferring mechanism has the advantages of reducing the panel deflection and of minimizing the contact problem between the panel and the transferring mechanism. Individual clamp of the mechanism has two distinct mechanical functions which are perfectly fixing a panel during the transferring and generating adequate tension for the panel. To determine the mechanical parameters of the clamp, panel deflection simulation was conducted and the result was verified by the panel deflection measurement. Also, fixing angle of a clamp could be determined by the free body force analysis of individual clamp. Finally clamp type transferring mechanism was actually manufactured and the transferring performance was verified during the water spraying condition of the package substrate's wet processes.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.20 no.1
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• pp.1-6
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• 2014

Properly designed plastic packages of fresh produce can preserve the quality by maintaining the optimal modified atmosphere (MA) at optimal low temperature conditions, but cannot do so at temperature abuse conditions in retail stage due to occurrence of injurious package atmosphere coming from imbalance between respiration and package gas permeation. Master packaging system consisting of a double-layered secondary package wrapping several individual (primary) packages has been proposed and applied recently to the commodities of sweet persimmon, king oyster mushroom, chestnut and strawberry. The master (secondary) pack is designed to be stored and distributed under chilled temperature, and then dismantled when moved to the retail display from the presale chilled storage. The master packaging system taking into consideration temperature dependence of produce respiration and package gas transfer was looked into with examination of its design variables to maintain the beneficial MA. Mathematical model was provided to help the design of master packaging system creating the desired MA. Its benefits of quality preservation and its limitations in practices of fresh produce marketing were discussed. Further research direction to extend the applicability of the produce master packaging system was presented.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.3
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• pp.402-408
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• 2016

Master packaging system consists of an inner individual package and secondary outer package. During the stages of chilled transport and distribution, the combination of primary individual package and secondary package was used to maintain a modified atmosphere for shiitake mushrooms. During the retail stage at higher temperature ($25^{\circ}C$), the primary individual package was exposed to display conditions after dismantling of the secondary packaging. The master packaging system was constructed to contain eight individual $30-{\mu}m$ thick polypropylene film bags of 500 g shiitake mushrooms inside a $40-{\mu}m$ low-density polyethylene bag. Carbon dioxide absorbent material [$Ca(OH)_2$] and/or moisture absorbent (superabsorbent polymer) were designed in their required amounts based on respiration characteristics and then applied to the outer secondary packaging in sachet form. Gas concentration of the packaging, temperature, and humidity were monitored throughout transport and storage. The quality of shiitake mushrooms was measured at the retail stage to determine the packaging effect. During the distribution stage of 108 h, $O_2$ and $CO_2$ concentrations in the master packaging system were maintained at 9~11% and 1~4% in the inner packaging, respectively, which are good for quality preservation. Compared to the control, the master packaging with $CO_2$ and/or moisture absorbents improved mushroom preservation and particularly reduced decay.

• The Journal of Industrial Distribution & Business
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• v.11 no.1
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• pp.29-38
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• 2020

Purpose: Understanding which product types of overseas travel (free independent travel vs. package travel) consumers will choose is one of the key issues of marketing and consumer behavior in travel agency management. Prior studies on overseas travel type preferences mainly focused on comparing regional differences (e.g., Asian vs. Westerner, or Korean vs. Australian, or Korean vs. Japanese, or American, French, Italian vs. Japanese) influencing the choice of overseas travel type. Another researchers focused on comparing cultural differences (e.g., individualism vs. collectivism, or individualistic culture vs. collectivistic culture), subcultural difference (e.g., acculturation; Koreans living in Republic of Korea vs. Koreans living in Australia), travel lifestyle, and socio-demographics (e.g., age, gender, income level, education level, marital status, occupation etc.). However, there are few studies that identify individual psychological differences (i.e., individual psychological differences within the same culture) influencing the choice of overseas travel type. Self-construal is a psychological factors that greatly influences choice behavior. The purpose of this study was to examine the role of self-construal as an antecedent variable influencing choice of overseas travel product type. Research design, data and methodology: To achieve the purpose of this study, the questionnaire survey method was used. Self-construal items composed of independent self-construal items and interdependent self-construal items. Product types of overseas travel were free independent travel (FIT) type versus package travel type. In this study, the correlation coefficient between independent self-construal and interdependent self-construal was nonsignificant. It meant that the relationship between independent self-construal and interdependent self-construal was orthogonal. Therefore it was analyzed that independent self-construal and interdependent self-construal separately. Reliability analysis, factor analysis, and logistic regression analysis (controlling gender and age) was used as the data analysis method. Results: According to the results of this study, the stronger independent self-construal, the more preference for the free independent travel type rather than package travel, and the stronger interdependent self-construal, the more preference for the package travel type rather than free independent travel. Conclusions: Self-construal is an antecedent variable influencing the choice of travel type. Travel agencies must consider the consumer's self-construal (independent self-construal vs. interdependent self-construal) before planning and designing overseas travel products.

• JSTS:Journal of Semiconductor Technology and Science
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• v.12 no.2
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• pp.139-149
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• 2012

A 3D stacked IC is made by multiple dies (possibly) with heterogeneous process technologies. Therefore, die-to-die variation in 2D chips renders on-package variation (OPV) in a 3D chip. In spite of the different variation effect in 3D chips, generally, 3D die stacking can produce high yield due to the smaller individual die area and the averaging effect of variation on data path. However, 3D clock network can experience unintended huge clock skew due to the different clock propagation routes on multiple stacked dies. In this paper, we analyze the on-package variation effect on 3D clock networks and show the necessity of a post silicon management method such as body biasing technique for the OPV induced 3D clock skew control in 3D stacked IC designs. Then, we present a parametric yield improvement method to mitigate the OPV induced 3D clock skew.

• Journal of Ginseng Research
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• v.17 no.3
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• pp.219-223
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• 1993

Assessment of root weight grade system for the numeral definition in Korea ginseng was tried by investigation of 13 boxes of the 15-root-grade of 4-year-old white ginseng as a model. In this case satisfaction to theoretical value was 58% in root weight and 50% in root number. The coefficient of variation (CV) was high (35%) for individual root weight in package. The CV of tap root weight 1 among package is low (7.1%) even though there was no significant correlation between tap root weight : and lateral root weight among roots. The mean percentage of tap root to root weight in each package ranged 61 to 74% with CV range of 16.5 to 33.2%. The CV was not much different between 1st and 2nd lateral root weight and the means was above 60%. Strict practice of numeral definition of root weight grade system will be prerequisite for chemical standardization of Korea ginseng.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.10
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• pp.183-190
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• 2003

Major device failures such as die cracking, interfacial delamination and warpage in flip chip packages are due to excessive heat and thermal gradients- There have been significant researches toward understanding the thermal performance of electronic packages, but the majority of these studies do not take into account the combined effects of thermo-mechanical interactions of the different package constituents. This paper investigates the thermo-mechanical performance of flip chip package constituents based on the finite element method with thermo-mechanically coupled elements. Delaminations with different lengths between the silicon die and underfill resin interfaces were introduced to simulate the defects induced during the assembly processes. The temperature gradient fields and the corresponding stress distributions were analyzed and the results were compared with isothermal case. Parametric studies have been conducted with varying thermal conductivities of the package components, substrate board configurations. Compared with the uniform temperature distribution model, the model considering the temperature gradients provided more accurate stress profiles in the solder interconnections and underfill fillet. The packages with prescribed delaminations resulted in significant changes in stress in the solder. From the parametric study, the coefficients of thermal expansion and the package configurations played significant roles in determining the stress level over the entire package, although they showed little influence on stresses profile within the individual components. These observations have been implemented to the multi-board layer chip scale packages (CSP), and its results are discussed.

• Korean Journal of Materials Research
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• v.19 no.5
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• pp.288-292
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• 2009

This article shows various factors that influence the thermal-cycling reliability of semiconductor devices utilizing the lead-on-chip (LOC) die attach technique. This work details how the modification of LOC package design as well as the back-grinding and dicing process of semiconductor wafers affect passivation reliability. This work shows that the design of an adhesion tape rather than a plastic package body can play a more important role in determining the passivation reliability. This is due to the fact that the thermal-expansion coefficient of the tape is larger than that of the plastic package body. Present tests also indicate that the ceramic fillers embedded in the plastic package body for mechanical strengthening are not helpful for the improvement of the passivation reliability. Even though the fillers can reduce the thermal-expansion of the plastic package body, microscopic examinations show that they can cause direct damage to the passivation layer. Furthermore, experimental results also illustrate that sawing-induced chipping resulting from the separation of a semiconductor wafer into individual devices might develop into passivation cracks during thermal-cycling. Thus, the proper design of the adhesion tape and the prevention of the sawing-induced chipping should be considered to enhance the passivation reliability in the semiconductor devices using the LOC die attach technique.