• Journal of Applied Biological Chemistry
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• v.61 no.1
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• pp.25-31
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• 2018

This study investigated the effect of different $O_2$ transmission rate (OTR) of films on surface temperature, weight loss, pH, $O_2$, $CO_2$ and sensory characteristics, microbial quality, total phenolic contents and 1,1-diphenyl-2-picryl hydrazyl radical scavenging activity of fresh-cut lettuce during storage at $10^{\circ}C$ for 7 days. $80{\pm}5g$ of fresh-cut lettuce were packaged with oriented polypropylene films respectively. The OTR of packaging materials was 5,000, 8,000 and $10,000cc/m^2{\cdot}day{\cdot}atm$. Quality characteristics showed significant differences during storage. The surface temperature was averaged 13 and lower in higher OTR of films. The weight loss of lettuce ranged from 2.8 to 5.4% and the highest loss showed in $5,000cc/m^2{\cdot}day{\cdot}atm$ of film. pH was increased during storage and the highest pH was found in $5,000cc/m^2{\cdot}day{\cdot}atm$. The $O_2$ content in the packaging was decreased with increasing $CO_2$ content during storage. The lowest $CO_2$ was found in $10,000cc/m^2{\cdot}day{\cdot}atm$. As OTR was decreased, antioxidant profile of lettuce was decreased. Total aerobic bacteria showed from 5.48 to 6.59 log CFU/g. From the result of the overall sensory test, the marketability of fresh-cut lettuce stored at $10^{\circ}C$ seemed to be maintained effectively over 5 days.

• Archives of design research
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• v.19 no.5 s.67
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• pp.363-372
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• 2006

The aim of this study is to shed light on the importance of female drivers, study their characteristics and needs, and create automobile designs in accordance with the study. The power of female consumers is greatly increasing in a modern society, To the extent that women became the core consumers. Companies are now turning their attention to female consumers in order to survive the fierce competition in the saturated markets. Moreover, it is becoming imperative for companies to actively develop products and services in female perspectives to meet the diversified needs of consumers. It is forecasted that vigorous research, analysis and understanding of the unique culture of women will be increasingly important now that women are emerging as core consumers. Only the companies that makes such efforts consistently can dominate the market. The automobile industry is not an exception. The world's major automobile companies including Volvo and Ford Motor Co. are keenly focusing on automobile exterior and interior designs for women. Korean companies are also designing cars that cater to women, starting with Lanos and Juliet of Daewoo Motors in 1998, yet specific and systematic research on the subject has not been made. This study aims to emphasize the power of female users, make a research and analysis on their needs and characteristics, and suggest car interior designs that cater to them.

• Korean Journal of Food Science and Technology
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• v.14 no.2
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• pp.122-124
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• 1982

The triglyceride composition of Korean hazel nut (Corylus heterophylla Fisch. var. Japonica koidz) was determined by high performance liquid chromatography (HPLC) using a $C_{18}$ micro Bondapack column with acetonitril-chloroform-tetrahydrofuran(75 : 15 : 10, v/v/v) and acetonitril-tetrahydrofuran (70 : 30, v/v) solvent mixtures as mobile phase. The triglyceride consisted of 4.14% $C_{38}$, 5.23% $C_{40}$, 10.03% $C_{42}$, 24.02% $C_{44}$, 48.73% $C_{46}$ and 7.85% $C_{48}$ with acetonitril-chloroform-tetrahydrofuran (75 : 15 : 10, v/v/v) mobile phase and 4.51% $C_{38}$, 5.98% $C_{40}$, 11.45% $C_{42}$, 25.14% $C_{44}$ and 52.92% $C_{46}$ with acetonitril-tetrahydrofuran (70 : 30, v/v) mobile phase.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.37-43
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• 2017

This review investigates the basic principle of physical interactions and failure mechanisms introduced in the materials and inner parts of semiconducting components under electromagnetic pulses (EMPs). The transfer process of EMPs at the semiconducting component level can be explained based on three layer structures (air, dielectric, and conductor layers). The theoretically absorbed energy can be predicted by the complex reflection coefficient. The main failure mechanisms of semiconductor components are also described based on the Joule heating energy generated by the coupling between materials and the applied EMPs. Breakdown of the P-N junction, burnout of the circuit pattern in the semiconductor chip, and damage to connecting wires between the lead frame and semiconducting chips can result from dielectric heating and eddy current loss due to electric and magnetic fields. To summarize, the EMPs transferred to the semiconductor components interact with the chip material in a semiconductor, and dipolar polarization and ionic conduction happen at the same time. Destruction of the P-N junction can result from excessive reverse voltage. Further EMP research at the semiconducting component level is needed to improve the reliability and susceptibility of electric and electronic systems.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.705-713
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• 2018

An automotive ball joint connects the suspension system to the steering system and helps to enable rotational and linear motion between the two elements for steering. This study examines a ball joint used in medium and large-sized pickup trucks. Ball joints consist of a stud, socket, bearing, and plug. The main structural performance metrics of ball joints are the pull-out strength and push-out strength. These structural parameters must meet certain criteria to avoid serious accidents. Test and simulation methods are used to investigate the design requirements, but tests are time-consuming and costly. In this study, we modeled ball joints in SolidWorks and performed a finite element analysis in Abaqus to predict structural performance. The analysis was used to obtain the structural performance required for the static analysis of a 2D axisymmetric model. The uncertainties in the manufacturing of the ball joint were assumed to be the manufacturing tolerances, and the dimensional design variables were identified through case studies. The manufacturing tolerances at each level were defined, and the results were compared with experimental results.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.672-679
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• 2018

This paper describes a methodology for shape design using an optimal design system, whereas generally a three dimensional analysis is required for such designs. An automatic finite element mesh generation technique, which is based on fuzzy knowledge processing and computational geometry techniques, is incorporated into the system, together with a commercial FE analysis code and a commercial solid modeler. Also, with the aid of multilayer neural networks, the present system allows us to automatically obtain a design window, in which a number of satisfactory design solutions exist in a multi-dimensional design parameter space. The developed optimal design system is successfully applied to evaluate the structures that are used. This study used a stress gauge to measure the maximum stress affecting the parts of the side housing bracket which are most vulnerable to cracking. Thereafter, we used a tool to interpret the maximum stress value, while maintaining the same stress as that exerted on the spot. Furthermore, a stress analysis was performed with the typical shape maintained intact, SM490 used for the material and the minimizing weight safety coefficient set to 3, while keeping the maximum stress the same as or smaller than the allowable stress. In this paper, a side housing bracket with a comparably simple structure for 36 tons was optimized, however if the method developed in this study were applied to side housing brackets of different classes (tons), their quality would be greatly improved.

• Journal of Pharmaceutical Investigation
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• v.32 no.2
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• pp.127-133
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• 2002

Levosulpiride is the 1evo-enantiomer form of racemic sulpiride, a benzamide derivative selectively inhibiting dopaminergic $D_2$ receptors at the trigger zone both in the central nervous system and in the gastrointestinal tract. The purpose of the present study was to evaluate the bioequiva1ence of two levosulpiride tablets, Levopride (SK Pharmaceutical Co., Ltd.) and Levopid (Dae Won Pharmaceutical Co., Ltd.), according to the guidelines of Korea Food and Drug Administration (KFDA). The levosulpiride release from the two levosulpiride tablets in vitro was tested using KP VII Apparatus II method with various different kinds of dissolution media (pH 1.2, 4.0, 6.8 buffer solution and water). Twenty eight normal male volunteers, $23.82{\pm}3.26$ years in age and $69.13{\pm}8.58$ kg in body weight, were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After one tablet containing 25 mg of levosulpiride was orally administered, blood was taken at predetermined time intervals and the concentrations of levosulpiride in serum were determined using HPLC method with fluorescence detector. The dissolution profiles of two levosulpiride tablets were very similar at all dissolution media. Besides, the pharmacokinetic parameters such as $AUC_t,\;C_{max}\;and\;T_{max}$ were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_t\;and\;C_{max}$ and untransformed $T_{max}$. The results showed that the differences in $AUC_t,\;C_{max}\;and\;T_{max}$ between two tablets based on the Levopride were -1.17%, 1.20% and -1.09%, respectively. There were no sequence effects between two tablets in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log(0.8) to log(1.25) $(e.g.,\;log(0.93){\sim}log(1.07)\;and\;log(0.90){\sim}log(1.14)\;for\;AUC_t\;and\;C_{max}$, respectively). The 90% confidence interval using untransformed data was within ${\pm}20%$ $(e.g.,\;-19.47{\sim}16.20\;for\;T_{max})$. All parameters met the criteria of KFDA guideline for bioequivalence, indicating that Levopid tablet is bioequivalent to Levopride tablet.

• Journal of Pharmaceutical Investigation
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• v.36 no.2
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• pp.143-148
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• 2006

Finasteride $[N-(1, 1-dimethylethyl)-3-oxo-4-aza-5{\alpha}-androst-1-ene-17{\beta}-carboxamide]$ is a 4-aza-3-oxosteroidal inhibitor of human $5{\alpha}-reductase$. The purpose of the present study was to evaluate the bioequivalence of two finasteride tablets, $Proscar^{\circledR}$ (MSD Korea Ltd.) and Procare (Hana Pharm. Co., Ltd.), according to the guidelines of the Korea Food and Drug Administration (KFDA). The release of finasteride from the two finasteride formulations in vitro was tested using KP VIII Apparatus II method with various dissolution media (pH 1.2, 4.0, 6.8 buffer solution and water). Twenty six healthy male subjects, $23.7\;{\pm}\;2.24$ years in age and $67.2\;{\pm}\;8.55\;kg$ in body weight, were divided into two groups and a randomized $2\;{\time}\;2$ cross-over study was employed. After two tablets containing 5 mg as finasteride was orally administered, blood samples were taken at predetermined time intervals and the concentrations of finasteride in serum were determined using HPLC with UV detector. The dissolution profiles of two formulations were similar in all tested dissolution media. The pharmacokinetic parameters such as $AUC_t,\;C_{max},\;and\;T_{max}$ were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_t,\;C_{max}$ and untransformed $T_{max}$. The results showed that the differences between two formulations based on the reference drug, $Proscar^{\circledR}$, were 6.39, 4.65 and -13.9% for $AUC_t,\;C_{max},\;and\;T_{max},$ respectively. There were no sequence effects between two formulations in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log 0.800 to log 1.25 $(e.g.,\;log\;0.990{\sim}log\;1.14\;and\;log\;0.977{\sim}log\;1.13 for\;AUC_t\;and\;C_{max},\;respectively)$. Thus, the criteria of the KFDA bioequivalence guideline were satisfied, indicating Procare tablet was bioequivalent to $Proscar^{\circledR}$ tablet.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.1
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• pp.59-65
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• 2012

Purpose: The purpose of this study was to determine the distribution and correlation of accommodative lag with refractive error. Method: We had tested the clinical refraction and the accommodative lag in clinically normal 49 young adults (total 98 eyes) aged 18 to 25 years without abnormal binocular function. Monocular and binocular accommodative lag were tested with 0.50 D cross-cylinder lens and near vision test chart which had cross-hairs after full correction of LogMAR visual acuity over 0.05. Results: There was no statistical differences in monocular accommodative lag between right ($0.64{\pm}0.64$ D) and left eye ($0.63{\pm}0.64$)(p=0.858). The accommodative lag of male was higher than female and the range of the value was broader than female in binocular accommodative lag (p=0.015). The wider the inter-pupillary distance was, the higher the accommodative lag was (p=0.003). However, there were no differences with age (p=0.800) and dominant eye (p=0.402). The ranges of accommodative lag of low, middle, and high myopia were 0.75 ~ -0.25 D, 1.25 ~ -0.50 D, and 1.50 ~ -0.75 D, respectively, and the regression was 'y = -0.03953x+0.09205'. Conclusions: These data suggest that clinically normal young adults with high amounts of refractive error have more variable accommodative lag and increased spherical equivalent refraction.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.12
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• pp.2394-2402
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• 2017

The frequency selective fading by multipaths determines a performance of underwater acoustic communication system in shallow littoral ocean. In this study, a characteristics of underwater acoustic channel and performance of multi-carrier system is evaluated in littoral ocean with a 50m deep water, an effective wave height of 0.5m and sandy mud bottom near Busan city. A multipath delay spread and time and frequency domain are presented as a function of a transmitter-to-receiver range. A bit-error-rate of a 5 channel 4FSK(Frequency Shift Keying) with a transmission rate of 1kbps, is examined and RS(Reed-Solomon) code is also adopted to remove a burst error due to time domain fading. A number of multipath are less than four and a bit-error-rate is decreased as an increase of a transmitter-to-receiver range which gives a congestion of multi-paths resulting in a decrease of time and frequency domain fading. The measured bit-error-rate is about 10-4 at greater than 600m of transmitter-to-receiver range.