• Composites Research
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• v.29 no.5
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• pp.249-255
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• 2016

The fiber metal laminates have been widely used at aerospace industry due to outstanding fatigue characteristic, corrosion resistance and impact resistance and so forth. The objective of this research is to establish the proper manufacturing variables for enhancing the interfacial energy release rate of fiber metal laminates using Taguchi method. The major variables of the manufacturing process are surface treatment, pre-specified temperature holding time and additional pressure. In order to determine the interfacial adhesive strength, the double cantilever beam and end-notched flexure tests were conducted. Afterward, Mode I and II energy release rates at various conditions were introduced signal-to-noise ratio with respect to each condition. Finally, the most efficient manufacturing variables are recognized using larger-the-better characteristic.

• Journal of Korea Society of Industrial Information Systems
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• v.17 no.2
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• pp.65-72
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• 2012

In the 21st century of information systems, the amount of information resources are ever increasing and the role of information searching system is becoming criticalto easily acquire required information from the web. Generally, it requires the user to have enough pre-knowledge and superior capabilities to identify keywords of information to effectively search the web. However, most of the users undertake searching of the information without holding enough pre-knowledge and spend a lot of time associating key words which are related to their required information. Furthermore, many search engines support the keywords searching system but this only provides collection of similar words, and do not provide the user with exact relational search information with the keywords. Therefore this research report proposes a method of offering expanded user relationship search keywords by analyzing user query patterns to provide the user a system, which conveniently support their searching of the information.

• Korean Parent-Child Health Journal
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• v.1
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• pp.56-74
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• 1998

The language of the newborn, like that of adults, is one of gesture, posture, and expression(Lewis, 1980). Helping parents understand and respond to their newborn's cues will make caring for their baby more enjoyable and may well provide the foundation for a communicative bond that will last lifetime. Infant state provides a dynamic pattern reflecting the full behavioral repertoire of the healthy infant(Brazelton, 1973, 1984). States are organized in a predictable emporal sequence and provide a basic classification of conditions that occur over and over again(Wolff, 1987). They are recognized by characteristic behavioral patterns, physiological changes, and infants' level of responsiveness. Most inportantly, however, states provide caregivers a framework for observing and understanding infants' behavior. When parents know how to determine whether their infant is sleep, awake, or drowsy, and they know the implications, recognition of states has for both the infant's behavior and for their caregiving, then a lot of hings about taking care of a newborn become much easier and more rewarding. Most parents have the skills and desire to do what is best for their infant. The skills 7373parents bring to the interaction are: the ability to read their infant's cues: to stimulate the baby through touch, movement, talking, and looking at: and to respond in a contingent manner to the infant's signals. Among the crucial skills infants bring to the interaction are perceptual abilities: hearing and seeing, the capacity to look at another for a period of time, the ability to smile, be consoled, adapt their body to holding or movement, and be regular and predictable in responding. Research demonstrates that the absence of these skills by either partner adversely affects parent-infant interaction and later development. Observing early parent-infant interactions during the hospital stay is important in order to identify parent-infant pairs in need of continued monitoring(Barnard, et al., 1989).

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.198-201
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• 2001

Porous structures of aluminum foam have been studied by using return aluminum scrap. The apparent foam shape, foam height, density, pore size and their distributions in various section areas of the experimental samples have been investigated. The sample have been cast into metallic mold, using aluminum foam prepared from a precursor based on pure Al ingot and return aluminum scrap mixed with various amounts of 1-2wt% increasing viscosity and foam agent materials. The process provides for flexibility in design of foam structures via relatively easy control over the amount of hydrogen evolution and the drainage processes which occur during foam formation. This is facilitated by manipulating parameters such as the foaming agent, thermal histories during solidification and mix melt viscosities. A metal for producing the foamed are decomposing a foaming agent in a molten metal such that there is an initial and a subsequent expansion due to foaming agent. It has been found that the Al porous foaming with variation amount of 1∼2wt% foam agent and at 2min holding time, which melting temperature has appeared homogeneous pore size at 650∼700$^{\circ}C$. The compression strength were 10-13 kg/min at 125ppi, and increased by higher pore density. The acoustical performance of the panel made with the foamed aluminum is considerably improved; its absorption coefficient shows NRC 0.6-0.8. It has been found that the Al foam is very preferable for the compactness of the thermal system.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.39 no.5
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• pp.43-50
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• 2002

To improve the current waveform of diode rectifiers, we propose a new operating principle for the voltage -doubler diode rectifiers. In the conventional voltage-doubler rectifier circuit, relatively large capacitors are used to boost the output voltage, while the proposed circuit uses smaller ones and a small reactor not to boost the output voltage but improve the input current waveform. A high input power factor of 97[%] and an efficiency of 98[%] are also obtained. The harmonic guide lines of proposed rectifier is no interfered with inverter switching, resulting in a simple, reliable and low-cost ac-to dc converters in comparison with the boost-type current-improving circuits.It compared conventional pulse-widthmodulated(PWM)inverter with half pulse-widthmodulated (HPWM) inverter. Proposed HPWM inverter eliminated dead-time by lowering switchingloss and holding over-shooting.

• Journal of the Korea Society of Computer and Information
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• v.16 no.10
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• pp.229-239
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• 2011

This study aims to suggest profitability models of local cultural festival to be a focal point of local culture to overcome the abuses as an annual event led by the local government agencies have been in force in every local areas currently, to elicit the local residents' voluntary participation and to engage the outside tourists in connection of a more effective promotion and marketing. The festival is attractive to people with that provoke mirth and inspire curiosity, but the festival is not a one-time event ongoing maintenance enlarge: It is absolutely necessary in order to effort to reach at consumer-oriented quality of service. Also this research intends to present a activation scheme by developing profitability models to make profits while holding a number of risks taking into account the characteristics of the local festival service carried out. To this end, based on established research, leading indicator and expert opinion were analyzed through multiple regression analysis.

• Korean Journal of Clinical Pharmacy
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• v.26 no.2
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• pp.137-149
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• 2016

Objective: Online pharmacies were introduced in some countries such as United States of America or Canada. They can provide benefits to consumer because they can buy and take conveniently drugs without limitation of location or time. In Korea, online pharmacies are illegal and only pharmacists can sell drugs to consumers or patients. Therefore, we investigated the knowledge of online pharmacy and the possible problem in Korea to survey pharmacists. Methods: We developed questionnaire based on previous articles about online pharmacy and surveyed nation-wide pharmacists by mail or e-mail. The data was analyzed by SPSS and Microsoft Excel. P-values less than 0.05 were statistically significant. Results: 175 pharmacists involved in this study. About introduction of online pharmacies, 53.1% were opposition while 10.3% were approval and 36.6% were conditional. Although online pharmacies were introduced, 46.3% pharmacists do not have a plan to start online pharmacy. However, the approval and tends about starting online pharmacies were higher in younger pharmacists (20s, 30s) (p < 0.05). The criteria of permission about opening online pharmacies were 100% pharmacist license regardless of holding off-line pharmacy. 53.7% pharmacists responded education about taking medication is impossible. When online pharmacies are introduced, 65.1% pharmacists responded traditional pharmacies are affected negatively. Pharmacists concerned that the competition with large-sized distribution corporations, reduced reliance between pharmacists and patients, illegal transaction of counterfeit drugs, increased misuse of drugs. Conclusion: These results showed that Korea pharmacists have negative standard on online pharmacies. Therefore it is required to be more cautious before introducing online pharmacy and it need strict watching system and continuous education and study for safety after introducing online pharmacy.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.9 s.180
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• pp.2183-2190
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• 2000

A thermal aging is observed in a primary reactor cooling system(RCS) made of a casting stainless steel when the RCS is exposed for long period at the reactor operating temperature, 290~3300C An investigation of effects of thermal aging on a low cycle fatigue characteristics included a stress variations caused by a reactor operation and trip, is required. The purpose of the present investigation is to find an effect of a thermal aging of the CF8M on a low cycle fatigue life. The specimen of CF8M are prepared by an artificially accelerated aging technique holding 300 and 1800hr at 4300C respectively. The low cycle fatigue tests for the virgin and two aged specimens are performed at the room temperature for various strain amplitudes($\varepsilon$ta), 0.3, 0.5, 0.8, 1.0, 1.2 and 1.5% strain. Through the experiment, it is found that the fatigue life is rapidly reduced with an creasing of the aging time. The experimental fatigue life estimation formulas between the virgin and two aged specimen are obtained and are proposed to a analysis purpose.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.1
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• pp.36-41
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• 2017

In this paper, $Si_3N_4/hBN$ ceramics with various hexagonal boron nitride (hBN) contents (0, 10, 20, or 30 wt%) were fabricated via spark plasma sintering (SPS) at $1500^{\circ}C$, 50MPa, and 10m holding time. The material properties such as the relative density, hardness, and fracture toughness were systematically evaluated according to the hBN content in the $Si_3N_4/hBN$ ceramics. The results show that relative density, hardness, and fracture toughness continuously decreased as the hBN content increased. In addition, peak-step drilling (with tool diameter $500{\mu}m$) was performed to observe the effects of hBN content in micro-hole shape and cutting force. A machined hole diameter of $510{\mu}m$ (entrance) and stable cutting force were obtained at 30 wt% hBN content. Consequently, $Si_3N_4/30wt%$ hBN ceramic is a feasible material upon which to apply semi-conductor components, and this study is very meaningful for determining correlations between material properties and machining performance.

• Journal of the Korean Applied Science and Technology
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• v.28 no.3
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• pp.273-283
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• 2011

The objective of this study was to determine the feeding effect of a diet containing Cordyceps with fly pupa on the changes in blood lipid profile from broiler chickens, fatty acids and thiobarbituric acid reactive substances (TBARS) in chicken meat. A total of 360 chicks (Ross strain 308) were divided on hatch day into four treated groups with respect to a 35-day feeding regimen: T1 (control group), T2 (2.0% Cordyceps with fly pupa), T3 (3.5% Corceps with fly pupa) and T3 (5.0% Cordyceps with fly pupa). Blood triacylglyceride and total cholesterol level was significantly decreased by 5.32-10.63% and 9.23-12.62%, respectively, in groups T2, T3 and T4 when compared to T1 (p<0.05). Water holding capacity was significantly highest in T2 (p<0.05), while there were no significant differences among groups T2, T3 and T. In chicken meat, the ratio of saturated fatty acid to unsaturated fatty acid was high in the T3 and T4 groups, the ratio of n-6 to n-3 fatty acid was low in the T2, T3 and T4 groups and oleic acid (18:1n-9) was high in the T2, T3 and T4 groups, when compared to T1 (p<0.05). TBARS tended to increase according to the storage time (in days), and was significantly lower in the chicken thigh muscles with skin in groups T2, T3 and T4 as compared to T1 (p<0.05). These results suggest that a diet containing 2.0-3.5% of Cordyceps with fly pupa may decrease blood lipid and improve both the shelf-life and quality of broiler chicken meat.