• Korean Journal of Materials Research
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• v.10 no.10
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• pp.665-670
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• 2000

Linear annealing method was developed to increase the bond strength of Si wafer pair mated at room tem­perature instead of conventional furnace annealing method. It has been known that the interval of the two mating wafer surfaces decreases and the density of gaseous phases generated at the interface increases with increase in an-nealing temperature. The new annealing method consisting of one heat source and light reflecting mirror used these two phenomena and was applied to Si$\mid$$\mid$Si and Si$\mid$$\mid$$SiO_2/Si$ bonding. The bonding interface observed directly by using IR camera and HRTEM showed clear bonding interface without any unbonded areas except the area generated by the dusts inserted into the mating interface at the room temperature. Crack opening method and direct tensile test was ap­pplied to measure the bond strength. The two methods showed similar results. The bond strength increased continuous­tly with the increase of annealing temperature.

• Journal of Food Hygiene and Safety
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• v.17 no.3
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• pp.157-165
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• 2002

A two-year survey of consumers'awareness and perception of genetically-modified (GM) foods was conducted during May through September of 2000 and 2001 with a random sample of Korean consumers. More than 68% of the respondents were exposed to some information related to GM foods. The greatest benefit of the development of GM foods was thought to be the remedy for the food shortage in the future. More than 90% of Korean consumers wanted GM foods to be labeled. About 18% of the respondents would buy GM foods voluntarily, whereas over 49% would not until they found out more. Only 40% of Korean consumers were found to realize that food items originated ken plants contain genes. More consumers responded that they would not buy herbicide-tolerant GM soybean but buy vitamin-enriched GM soybean. It seemed to be that many Korean consumers do not make decisions of acceptance or rejection of GM foods not on the basis of biotechnology but on the basis of the word(5) used to describe the products, such as herbicide and vitamin. Only 4% of Korean consumers responded that GM foods were the greatest safety-threatening factor of Korean foods.

• The Journal of the Korea Contents Association
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• v.15 no.1
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• pp.171-184
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• 2015

This study aims to explore the realities of life and the utilizing experience of housing improvement service among the vulnerable living in the indecent house. For this purpose of this study, we conducted in-depth interview with nine interviewees. As the result of this study, we figured out that the vulnerable living in the poor house had experienced psychological withdrawals, restricted of social activities, health problems, and feelings of insecurity. However, they could not afford to improve their houses because they were living below or near the poverty line. Local government provided the housing improvement service to cope with this problem. The people received this service gave positive reviews. Since their residential environment was improved, they felt easiness, strengthened social relationships, and expected a warm winter. Despite of 'thankful service', the housing improvement service had some limitations. Because of the limited budgets, full-scale construction services were unfeasible. Also we figured out it is necessary to make a change in housing policies for the people living in the poor houses. In the conclusion, we discussed and proposed the policies and practical suggestions.

• Anxiety and mood
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• v.7 no.1
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• pp.22-28
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• 2011

Objective : Social anxiety disorder (SAD) has been characterized by a marked sense of anxiety provoked by exposure to one or more social situations. It has been well-known that the cultural characteristics of a society strongly affect the expression of SAD symptoms. The current study attempted to explore clinical and cultural characteristics of social anxiety symptoms in the Korean nonclinical population. Methods : 801 volunteers who participated in the national social anxiety screening day, which was held by Korean academy of anxiety disorders, were invited to complete the self-report version of Liebowitz social anxiety scale (LSAS-SR). A total of 691 participants completed the LSAS-SR and other information related to this study. Results : Social anxiety symptoms were reported by a great percentage of subjects, as displayed by the relatively high mean LSAS scores (44.58 ; SD=25.60). There were no significant differences in total LSAS score according to sex, education, or marital status. The three most fearful or avoided situations for participants, as measured by the percentage of subjects who had a score of more than 3 on each LSAS item were as follows: item 6 (acting, performing, or giving a talk in front of an audience ; 29.67% for fear and 22.72% for avoidance), item 16 (speaking up in a meeting ; 25.62% for fear and 21.56% for avoidance), and item 15 (being the center of attention; 13.89% for fear and 9.70% for avoidance). Conclusion : The Korean participants in this study demonstrated a high level of SAD symptoms. Our subjects reported that they were more likely to be fearful or avoid passive situations such as being the center of attention as compared with results from a study of western society which indicated that western people were more likely to be fearful or avoid active situations. These findings emphasize the importance of considering a patient's cultural background when evaluating SAD symptoms.

• Applied Chemistry for Engineering
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• v.30 no.5
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• pp.620-626
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• 2019

In this study, the effects of the structural properties of the catalyst on CO oxidation reaction by controlling the $Cu/CeO_2$ catalyst amount and calcination temperature were studied, and also the CO conversion rate of the catalyst at the temperature range of $100{\sim}300^{\circ}C$ was evaluated. XRD, Raman, BET, $H_2-TPR$, and XPS analyses were performed to confirm the effect of changes in the structural properties on the chemical properties of the catalyst. The result confirmed that a substitution bond between Cu and Ce was formed and a lot of Cu and Ce bonds were formed when the catalyst carrying 5 wt.%. Of Cu was calcined at $400^{\circ}C$. The Cu-Ce binding was confirmed by peak shifts in Raman analysis and also peaks appeared in $H_2-TPR$. In addition, the balance state analysis demonstrated that a lot of surface labile oxygen molecules are formed, which can be more easily contributed to the reaction with $Ce^{3+}$ species known to form a substitution bond easily. It was found that CO conversion rate of the catalyst used in this study was close to 100% at $150^{\circ}C$.

• Journal of Energy Engineering
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• v.28 no.3
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• pp.18-25
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• 2019

In this study, in order to solve the problem of the program of calculating code input by experienced users in the power generation, the wide area energy network research group developed the local heating operation analysis program EntPLAN, which can be easily used by anyone, including scalability, with domestic technology. Therefore, the Commission intended to compare the heat sources, heat demand, and the results of operation of the combined heat plant (CHP) on the energy network through simulation with the EnetPLAN and the program A on the market. The results showed that the heat and power output on the energy network of the EnetPLAN and A programs were mostly similar in pattern in the simulation results of the heat supply and the operation method of the accumulator. This enabled the application of the simulation for the various operation modes of the cogeneration facilities existing on the energy network. It is expected that EntPLAN, which was developed with domestic technology, will be easily applied in the field in the future and will present efficient operation simulation results.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.5
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• pp.683-690
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• 2021

The ventilation system of the engine room of a ship is generally installed to supply the combustion air necessary for the internal combustion engine and to remove the heat source generated in the engine room, and it must satisfy the international standard (ISO 8861) for the design conditions and calculation standards for the ventilation of the ship engine room. The response delay of the ventilation system including the fire detector is affected by the airflow formed inside the area and the location of the fire detector. In this study, to improve the initial fire detection response speed of a fire detector installed on a fishing vessel and to maintain the sensitivity of the installed detector, the smoke behavior was simulated using the air flow field inside the engine room, the amount of combustion air in the internal combustion engine, and the internal pressure of the engine room as variables. Analysis of the simulation results showed that reducing the flow rate in the air flow field and increasing the vortex by reducing the internal pressure of the engine room and installing a smoke curtain would accelerate the rise of the ceiling of the smoke component and improve the smoke detector response speed and ventilation system.

• The Journal of the Convergence on Culture Technology
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• v.7 no.2
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• pp.443-451
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• 2021

This study compared and analyzed the thermal characteristics based on the ratio of moisture content of infected and non-infected Bursaphelenchus Xylophilus by heat of combustion experiment. The experiment results are as follows. The analysisresult of the ratio of water content shows that 19.92% on average for infected Bursaphelenchus Xylophilus and 26.27% for non-infected which decreases water content as the size of conduction, convection, and radiant heat increases in case of fire. As the vaporization of the moisture content accelerates, the average moisture content is reached, and the result is contrary to the thermal characteristics of the wood that the moisture content is not ignited by a heat source when the moisture content is under 15%. The combustion heat analysis result showed that infected and non-infected Bursaphelenchus Xylophilus had no significant difference in combustion heat at about 3%. However, it shows that combustion heat is higher than other species. In conclusion, decreasing in moisture content based on the increasing conduction, convection, and radiant heat is one of the direct causes of ignition, and the lower the moisture content, the faster the fire spreads.

• Korean Journal of Optics and Photonics
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• v.32 no.2
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• pp.49-54
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• 2021

In this paper, we design and construct the equipment to manufacture large-diameter optical fiber end caps, which are the core parts of high-power fiber lasers, and we fabricate large-diameter optical fiber end caps using the home-made equipment. This equipment consists of a CO2 laser as a fusion-splice heat source, a precision stage assembly for transferring the position of a large-diameter optical fiber and an end cap, and a vision system used for alignment when the fusion splice is interlocked with the stage assembly. The output of the laser source is interlocked with the stage assembly to control the output, and the equipment is manufactured to align the polarization axis of the large-diameter polarization-maintaining optical fiber with the vision system. Optical fiber end caps were manufactured by laser fusion splicing of a large-diameter polarization-maintaining optical fiber with a clad diameter of 400 ㎛ and an end cap of 10×5×2 ㎣ (W×D×H) using home-made equipment. Signal-light insertion loss, polarization extinction ratio, and beam quality M2 of the fabricated large-diameter optical fiber end caps were measured to be 0.6%, 16.7 dB, and 1.21, respectively.

• Applied Chemistry for Engineering
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• v.32 no.2
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• pp.143-148
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• 2021

A thermally conductive 200 ㎛ thick polyimide-based film was made from a polyamic acid (PAA) precursor containing graphene prepared from graphite rod using an electrostatic discharge method in order to improve the thermal conductivity and expand the applicability of polyimide (PI) film. Properties of graphene produced by electrostatic discharge were measured by Raman spectroscopy, transmission electron microscopy and X-ray photoelectron spectroscopy (XPS). As a result of Raman spectrum and XPS analyses of as-prepared graphene, the ID/IG ratio was 0.138 and C/O value was 24.91 which are excellent structural and surface chemical properties. Moreover, thermal conductivities of polyimide films increased exponentially according to graphene contents but when the graphene content exceeded 40%, the polyimide film could not maintain its shape. The thermal conductivity of carbonized PI film made from PAA containing 40 wt% of graphene was 51 W/mK which is greatly enhanced from the pristine carbonized PI film (1.9 W/mK). This result could be originated from superior properties of graphene prepared from the electrostatic discharge method.