• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.9
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• pp.558-565
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• 2017

Hybrid insulators that have the advantages of both porcelain (high mechanical strength and chemical stability) as well as polymer (light weight and high resistance to pollution) insulators, can be used in place of individual porcelain and polymer insulators that are used for both mechanical support as well as electrical insulation of overhead power transmission lines. The most significant feature of hybrid insulators is the presence of porcelain/polymer interfaces where the porcelain and polymer are physically bonded. Individual porcelain and polymer insulators do not have such porcelain/polymer interfaces. Although the interface is expected to affect the mechanical/electrical properties of the hybrid insulator, systematic studies of the adhesion properties at the porcelain/polymer interface and the effect of the interface on the insulation characteristics and electric field distribution of the hybrid insulator have not been reported. In this study, we fabricated small hybrid insulator specimens with various types of interfaces and investigated the effect of the porcelain/polymer interface on the microstructure, insulating characteristics, and electric field distribution of the hybrid insulators. It was observed that the porcelain/polymer interface of the hybrid insulator does not have a significant effect on the insulating characteristics and electric field distribution, and the hybrid insulator can exhibit electrical insulating properties that are similar or superior to those of individual porcelain and polymer insulators.

• Safety and Health at Work
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• v.7 no.4
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• pp.331-339
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• 2016

Background: Occupational risk management is known as a catalyst in generating superior returns for all stakeholders on a sustainable basis. A number of companies in Ghana implemented health and safety measures adopted from international companies to ensure the safety of their employees. However, there exist great threats to employees' safety in these companies. The purpose of this paper is to investigate the level of compliance of Occupational Health and Safety management systems and standards set by international and local legislation in power producing companies in Ghana. Methods: The methodology is conducted by administering questionnaires and in-depth interviews as measuring instruments. A random sampling technique was applied to 60 respondents; only 50 respondents returned their responses. The questionnaire was developed from a literature review and contained questions and items relevant to the initial research problem. A factor analysis was also carried out to investigate the influence of some variables on safety in general. Results: Results showed that the significant factors that influence the safety of employees at the hydroelectric power plant stations are: lack of training and supervision, non-observance of safe work procedures, lack of management commitment, and lack of periodical check on machine operations. The study pointed out the safety loopholes and therefore helped improve the health and safety measures of employees in the selected company by providing effective recommendations. Conclusion: The implementation of the proposed recommendations in this paper, would lead to the prevention of work-related injuries and illnesses of employees as well as property damage and incidents in hydroelectric power plants. The recommendations may equally be considered as benchmark for the Safety and Health Management System with international standards.

• Food Science of Animal Resources
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• v.38 no.4
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• pp.664-678
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• 2018

This study was carried out to establish shelf life for pork cutlet of ground meat and pork lard by using various quality indicators and to understand how quality changes in these products are accelerated by temperature. The samples were selected and purchased from markets in Korea, and the chosen quality indicators were total aerobic counts and coliform group in microbiological analyses, thiobarbituric acid reactive substances assay, volatile basic nitrogen, pH, acid value, and peroxide value in physical chemical analyses, and sensory evaluation. The pork cutlet samples were stored at $-18^{\circ}C$, $-6^{\circ}C$, and $-1^{\circ}C$, whereas pork lard samples were stored at $10^{\circ}C$, $25^{\circ}C$, $35^{\circ}C$, and $45^{\circ}C$. These temperature conditions were set to real distribution conditions. The samples were then analyzed using various models including of reaction orders, arrhenius equation, and $Q_{10}$ value. The quality limits for each sample were calculated, and shelf life was estimated. The results of this experiment highlighted the importance of temperature control during the distribution process of these products and revealed that temperature is a useful parameter for the establishment of a basic database for shelf life.

• Fashion & Textile Research Journal
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• v.20 no.5
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• pp.520-532
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• 2018

This study examines whether any correlation exists amongst participative motivation in an educational fashion training program, participants' program satisfaction and performance. In addition, this study investigates the moderating effect of participants' self-efficacy and job engagement in the influence of participative motivation on program satisfaction. Questionnaire data from 212 employed learners who participated in one or more educational fashion training programs were analyzed. For the data analysis, SPSS 24.0 statistical package was used. The study results were as follows. First, the participative motives of the educational fashion training program were grouped into the following three factors: goal-oriented, learning-oriented, and organizational support. Second, learning-oriented participative motivation positively affected their program satisfaction. Third, higher program satisfaction led better program performance. Fourth, there was a significant difference in the magnitude of the effect of learning-oriented participative motivation on satisfaction according to self-efficacy. Fifth, there was a significant difference in the magnitude of the effect of goal-oriented participative motivation on satisfaction according to vigor. Even if the participative motivation in an educational fashion training program predicts the program satisfaction, the strength is changed by interacting with the self-efficacy and vigor. The results of the study provide various implications for educators or policy makers who are interested in educational fashion training program development.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.5
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• pp.907-918
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• 2000

The pyrolysis characteristics of celluloses and plastics, which are the principal materials contributing to the municipal solid wastes(MSWs), was investigated with a thermal gravimetric analysis reaction system. The experiments were carried out in a nitrogen atmosphere in the temperature range of 400~900K at various experimental conditions. Also, a modified pyrolysis model for compressed MSWs has been proposed. Varing the heating rate to 20, 30, 40K/min, reaction orders of MSWs' main component were around 1.1~1.9, activation energies were 117~166kJ/mol for celluloses and 187~239kJ/mol for plastics. Char yield was proportional to the heating rate, particle size, and compressed ratio. The model proposed in this study, which is applying Arrhenius equation and thermodynamics, is closer to the experimental results than the conventional model.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.43 no.3 s.309
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• pp.8-15
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• 2006

Obstacle detection is an important task for many mobile robot applications. The methods using stereo vision and optical flow are computationally expensive. Therefore, this paper presents a vision-based obstacle detection method using only two view images. The method uses a single passive camera and odometry, performs in real-time. The proposed method is an obstacle detection method using 3D reconstruction from taro views. Processing begins with feature extraction for each input image using Dr. Lowe's SIFT(Scale Invariant Feature Transform) and establish the correspondence of features across input images. Using extrinsic camera rotation and translation matrix which is provided by odometry, we could calculate the 3D position of these corresponding points by triangulation. The results of triangulation are partial 3D reconstruction for obstacles. The proposed method has been tested successfully on an indoor mobile robot and is able to detect obstacles at 75msec.

• Korean Journal of Food Science and Technology
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• v.29 no.1
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• pp.26-31
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• 1997

Bee venom (Apis mellifera) phospholipase $A_2$ solubilized in reversed micelles containing small amount of water stabilized by surfactant could catalyze the hydrolysis of dipalmitoyl phosphatidylcholine (DPPC). A sensitive and simple high performance liquid chromatographic (HPLC) methodology of phospholipase $A_2$ assay for the hydrolysis of DPPC was developed. Kinetic analysis of the phospholipase $A_2$-catalyzed reaction was found to be possible in reversed micelles. Among the surfactants and organic solvents tested, aerosol-OT and isooctane were most effective for the hydrolysis of DPPC in reversed micelles. Optimal temperature, optimal pH, $K_{m,app.},\;V_{max.,app.}$ and activation energy were determined to be $35{\sim}40^{\circ}C$, 7.0, 8.73 mM, 2.83 units/㎎ protein and 12.31 kcal/mole, respectively. The hydrolysis activity was dependent on water content and maximum activity was obtained at R value (=[water]/[aerosol-OT]) of 10.0.

• Textile Coloration and Finishing
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• v.6 no.2
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• pp.55-62
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• 1994

The mend for fabric products has been increased remarkably with increasing population, housings, mutistory buildings,...and etc. during the last two decades. However, since fabrics are highly combustible and can produce toxic gases during the combution, fabric products can result in serious human injury as well as financial damage. Acknowledged by this, a new phosphorus based flame retardant suitable for PET fabric has been synthesized by making use of the reaction of diphenyl chloro phosphate and hexamethylenediamine. Since the starting meterials are relatively cheap and the yield of this reaction is high (more than 90%), this reaction seems to be very effective as wall as very economic. By analyzing various spectrophotometric analysis data such as NMR, FT-IR, and Mass, this new flame retardant is identified to be N,N’-Bis(diphenyl chlorophosphoro)diamino hexane. In the mean time, DSC measurement has shown that the melting point and the boiling point of this material are around 115$^{\circ}C$ and around 40$0^{\circ}C$, respectively. The flame retardancy test done on the PET fabric processed by this flame retardant have shown excellent in times of flame contact, times of flame contact for washable. The most economical finishing condition estimated 10% in concentration of BDPDH, Moreover, it has been also found that the drape stiffness of the PET fiber processed by the flame retartant is changed very litter compared to the unprocessed original PET fabrics. Judging from this, the potential of this new phosphrdus based compond as a flame retardant for PET fabric seems to be high.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.5 s.122
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• pp.415-426
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• 2007

In a link motion punch press, numerous links are interconnected and each link executes a constrained motion at high speed. As a consequence, dynamic unbalance force and moment are transmitted to the main frame of the press, which results in unwanted vibration. This degrades productivity and precise stamping work of the press. This paper presents an effective method for reducing dynamic unbalance in a link motion punch press based upon kinematic and dynamic analyses. Firstly, the kinematic analysis is carried out in order to understand the fundamental characteristics of the link motion mechanism. Then design variable approach is presented in order to automate the model setup for the mechanism whenever design changes are necessary. To obtain the inertia properties of the links such as mass, mass moment of inertia, and the center of mass, 3-dimensional CAD software was utilized. Dynamic simulations were carried out for various combinations of design changes on some links having significant influences on kinematic and dynamic behavior of the mechanism.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.3
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• pp.242-248
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• 2017

Recently, Population has been concentrated in cities due to rapid economic growth. As a result, urban buildings are becoming more dense, high-rise, and diversified. The shape of these urban buildings increases the risk of fire, accidents and crime. The narrow living space has the characteristic of the unchanged floor. In case of a fire, the living space of the narrow residence is large in the damage because the smoke diffusion rate is fast. The radio wave transmittance and transmission distance of wireless communication used in fire fighting operations vary depending on the type of building materials and buildings. Therefore, this paper analyzes the building materials and structural characteristics of the narrow residential space for efficient fire fighting operations. We have developed a communication environment solution for a narrow residential space for the optimal fire fighting operation through the measurement of the radio wave transmittance and the transmission distance of the wireless communication.