• Korean Institute of Interior Design Journal
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• v.20 no.5
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• pp.217-225
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• 2011

The meaning and role of public space has existed based on the periodical situation like history. The more the time has passed, the faster the meaning of it has changed. We can see the differences of it from the one which used to be. This study is about Platoon Kunsthalle which is so-called the complex cultural space. The purpose of this study is to show how the user is related to the program for the planning of the public space. It is based on the procedure of the research with absorbing the place. The people who are using the space are absorbed for knowing the user's action. And then, the specific actions are written and the status of the using space is photographed. The research is based on asking and answering about that. The result of this study is as follows : The first is that young people between 20's and 30's are using a hall comparing with other age through daily using of space and features of users. Also, Using between 7p.m. and 9p.m., a dinnertime, takes the first place and using of meals and beverages is major at lunch due to restaurant and bar. User behavior of "sitting" is the biggest part and the hall is used for the public purpose connected with "talking". The second is that the daily hall space is classified with the spacial area indirectly based on the condition. Also, it depends on the time and the using. The third is that the unusual hall space is depended on the program which is the role of leading the extention of using the space. That is why the program is important because it is effected directly to the way of using the space and the place of the furniture. I am looking forward that this study is the basic data for the planning of the public space in the complicated culture.

• The Journal of Advanced Prosthodontics
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• v.10 no.5
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• pp.347-353
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• 2018

PURPOSE. The purpose of this study was to evaluate the marginal discrepancy of heat-pressed ceramic veneers manufactured using a CAD/CAM system. MATERIALS AND METHODS. The ceramic veneers for the abutment of a maxillary left central incisor were designed using a CAD/CAM software program. Ten veneers using a microstereolithography apparatus (AM group), ten veneers using a five-axis milling machine (SM group), and ten veneers using a traditional free-hand wax technique (TW group) were prepared according to the respective manufacturing method. The ceramic veneers were also fabricated using a heat-press technique, and a silicone replica was used to measure their marginal discrepancy. The marginal discrepancies were measured using a digital microscope (${\times}160$ magnification). The data were analyzed using a nonparametric Kruskal-Wallis H test. Finally, post-hoc comparisons were conducted using Bonferroni-corrected Mann-Whitney U tests (${\alpha}=.05$). RESULTS. The $mean{\pm}SD$ of the total marginal discrepancy was $99.68{\pm}28.01{\mu}m$ for the AM group, $76.60{\pm}28.76{\mu}m$ for the SM group, and $83.08{\pm}39.74{\mu}m$ for the TW group. There were significant differences in the total marginal discrepancies of the ceramic veneers (P<.05). CONCLUSION. The SM group showed a better fit than the AM and TW groups. However, all values were within the clinical tolerance. Therefore, CAD/CAM manufacturing methods can replace the traditional free-hand wax technique.

• Journal of Korean Society of Forest Science
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• v.90 no.3
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• pp.388-397
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• 2001

In forestry, where improvement of labor environment is quite impossible, improved posture would result in direct effects by preventing waste of physical strength, prevention of accidental injury caused by fatigue accumulated on certain body parts, and prevention of human error by inattentiveness due to weakened body. Therefore, this research carried on analysis of working posture in manual forest work(thinning using chain-saw, salvage cutting using chain-saw, clearing using hand saw, clearance of twiner using sickle, pruning using saw with a long handle, and tending of young growth using sickle) using OWAS analysis system. According to the OWAS method, percentage of OWAS action categories III and IV in the tasks using chain-saw and sickle was higher than another tasks. For the compared middle skillful worker group and low skillful worker group at felling work using chain-saw, percentage of OWAS action categories IV in middle skillful worker group was 5.1%, and low skillful worker group was 14.1%.

• Archives of design research
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• v.20 no.2 s.70
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• pp.5-16
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• 2007

The main objective of our research is analyzing user's emotional changes while using a product, to reveal the influence of usability on human emotions. In this study we have extracted some emotional words that can come up during user interaction with a product and reveal emotional changes through three methods. Finally, we extracted 88 emotional words for measuring user's emotions expressed while using products. And we categorized the 88 words to form 6 groups by using factor analysis. The 6 categories that were extracted as a result of this study were found to be user's representative emotions expressed while using products. It is expected that emotional words and user's representative emotions extracted in this study will be used as subjective evaluation data that is required to measure user's emotional changes while using a product. Also, we proposed the effective methods for measuring user's emotion expressed while using a product in the environment which is natural and accessible for the field of design, by using the emotion mouse and the Eyegaze. An examinee performs several tasks with the emotion mouse through the mobile phone simulator on the computer monitor connected to the Eyegaze. While testing, the emotion mouse senses user's EDA and PPG and transmits the data to the computer. In addition, the Eyegaze can observe the change of pupil size. And a video camera records user's facial expression while testing. After each testing, a subjective evaluation on the emotional changes expressed by the user is performed by the user him/herself using the emotional words extracted from the above study. We aim to evaluate the satisfaction level of usability of the product and compare it with the actual experiment results. Through continuous studies based on these researches, we hope to supply a basic framework for the development of interface with consideration to the user's emotions.

• The Korean Journal of Elementary Counseling
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• v.4 no.1
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• pp.151-166
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• 2005

The purpose of the study was to find the effect of play-using assertion training program on elementary school children's self-expression, interpersonal relationship and self-efficacy. For the purpose of the study, the researcher sets hypotheses as follows. Hypothesis I : The play-using assertion training program has significant effect in elementary school children's self-expression. Hypothesis II : The play-using assertion training program has significant effect on elementary school children's interpersonal relationship. Hypothesis III: The play-using assertion training program has significant effect on elementary school children's self-efficacy. To verify these hypotheses, the researcher selected 10 students of 4th grade in C elementary school as a experimental group, and 11 students of 4th grade in O elementary school as a controlled group. Both schools are located at Boryoung, Chungnam. In the experimental group, the researcher administered the play-using assertion training program once a week for ten weeks. The play-using assertion training program are made by the researcher based on Jeon(1985) and Byoun and Kim(1980). To measure self-expression, the scale of self-expression made by Byoun & Kim(1980) was used. To measure interpersonal relationship, the scale of relationship change made by Schlin and Guerney(1971) was used. The scale was translated by Lee and Moon(1980). To measure self-efficacy, the scale of self-efficacy made by Han(2002) was used. The scale is based on Kim and Cha(1996) and Kim(1997). The result of the study is that the play-using assertion training program gives positive effects on students' self-expression, especially in physical area. Second, the play-using assertion training program gives positive effects on students' interpersonal relationship, especially in satisfaction, communication and friendliness. Third, the play-using assertion training program generally does not give positive effects on students' self-efficacy, but give significant effects on confidence and self-control efficacy which are sub-areas of self-efficacy.

• Korean Journal of Applied Biomechanics
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• v.30 no.4
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• pp.311-319
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• 2020

Objective: The purpose of this study was to examine of this study is to study the effect of squat exercise on muscle activation in a sling device using various types of ropes and to propose an effective sling exercise method for strengthening the lower extremity strength. Method: 20 adult male subjects (age: 25.2±2.4 yrs, height: 176.5±3.2 cm, weight: 77.2±4.5 kg) participated in this study. In the experiment, a total of four squats were conducted: squat [SE], sling squat using inelastic rope [IR], sling squat using elastic rope [ER], and sling squat using two elastic ropes [TER]. Squats were performed 5 times for each condition, and a 60-second break was given for each condition to minimize muscle fatigue. The activation of biceps brachii, rectus femoris, gastrocnemius, and tibialis anterior muscles was measured. Results: It was found that the activation of all muscles was the lowest during the squat exercise [SE]. During the sling squat using inelastic rope [IR], the muscle activation of the biceps brachii was the highest. During the sling squat using elastic rope [ER], the activation of the rectus femoris, gastrocnemius, and tibialis anterior muscles was found to be the highest. In the sling squat using two elastic ropes [TER], most of the muscle activation was similar to that of the sling squat using inelastic rope [IR]. Conclusion: Our results of the experiment, it was found that sling squat exercise using elastic rope had a positive effect on the activation of all muscles. It is thought that performing a squat exercise under moderate weight load and unstable conditions, such as sling squat exercise using elastic rope, can increase the muscle activity of the lower limbs and perform more effective exercise effect than performing a conventional squat exercise under stable conditions. In the future, if research is conducted not only on adult men, but also on various ages and patients, it will be able to provide positive help in improving balance, stability and stamina through squat exercise.

• Design & Manufacturing
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• v.16 no.3
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• pp.9-15
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• 2022

In order to reduce the manufacturing costs of the glass lens, it is necessary to manufacture a lens using a UV curable resin or a thermosetting resin, which is a curable material, in order to replace a glass lens. In the case of forming a lens using a thermosetting material, it is necessary to form several lenses at once using the wafer-level lens manufacturing technologies due to the long curing time of the material. When a lens is manufactured using a curable material, an error in the shape of the lens due to the shrinkage of the material during the curing process is an important cause of defects. The major factors for these shape errors and deformations are the shrinkage and the change of mechanical properties in the process of changing from a liquid material during curing to a solid state after complete curing. Therefore, it is necessary to understand the curing process of the material and to examine the shrinkage rate and change of physical properties according to the degree cure. In addition, it is necessary to proceed with CAE for lens molding using these and to review problems in lens manufacturing in advance. In this study, the viscoelastic properties of the material were measured during the curing process using a rheometer. Using the results, Rheological investigation of cure kinetics was performed. At the same time, The shrinkage of the material was measured and simple mathematical models were created. And using the results, the molding process of a single lens was analyzed using Comsol, a commercial S/W. In addition, the experiment was conducted to compare and verify the CAE results. As a result, it was confirmed that the shrinkage rate of the material had a great influence on the shape precision of the final product.

• Journal of the Korean Institute of Gas
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• v.26 no.4
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• pp.18-26
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• 2022

The Korean government is conducting heat-using equipment(industrial boiler) inspection in accordance with the Energy Use Rationalization Act because of the heat-using equipment(industrial boiler)'s risks such as explosion and fire, and safe use and management. This paper aimed to setup the safe and performance vulnerabilities from database based on the inspection results for heat-using equipment(industrial boiler). This study surveyed the inspection results of 1,249 heat-using equipment(industrial boiler) which were failed inspection of heat-using equipment(industrial boiler) from january 2016 to december 2020. And the analysis method is to inform safety and performance vulnerability categories of heat-using equipment(industrial boiler) by statistically analyzing the failure reasons of boiler type and inspection type which are high variance in failure rate. The safety and performance vulnerability categories was abbreviated into 18 cases. And each catagory's main reason for failure was suggested by additional analyzing the opinions of inspectors. This paper would be the basic source and the comprehensive information dealing with the safety and performance vulnerability of heat-using equipment(industrial boiler).

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.2
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• pp.226-233
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• 2023

In this study, we compared the performance of several refrigeration cycles using different refrigerants and utilizing the cold heat of liquefied natural gas (LNG) for the liquefaction of carbon dioxide. The final conditions for the liquefied CO₂ were set to -20℃ and 20 bar. The refrigerants used included R404a, ammonia, propane, and propylene using a vapor recompression refrigeration cycle. For the refrigeration cycle, the CO₂ at room temperature and pressure was compressed in a two-stage compression process with an intermediate cooling stage using a refrigeration unit. To compare with the liquefaction process using refrigeration, we compressed the CO₂ to 8 bar in a single compression stage and cooled it to around -50℃ using the cold heat of the LNG before liquefying it. Results showed that using ammonia as the refrigerant required the least amount of compressor power for the liquefaction process, and the heat transfer area of the evaporator was the smallest when using propylene as the refrigerant. Using the cold heat of LNG instead of refrigeration using R404a resulted in approximately 69% less energy consumption.

• International Journal of Highway Engineering
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• v.18 no.5
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• pp.117-125
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• 2016

PURPOSES : The density in uninterrupted traffic flow facilities plays an important role in representing the current status of traffic flow. For example, the density is used for the primary measures of effectiveness in the capacity analysis for freeway facilities. Therefore, the estimation of density has been a long and tough task for traffic engineers for a long time. This study was initiated to evaluate the performance of density values that were estimated using VDS data and two traditional methods, including a method using traffic flow theory and another method using occupancy by comparing the density values estimated using vehicular trajectory data generated from a radar detector. METHODS : In this study, a radar detector which can generate very accurate vehicular trajectory within the range of 250 m on the Joongbu expressway near to Dongseoul tollgate, where two VDS were already installed. The first task was to estimate densities using different data and methods. Thus, the density values were estimated using two traditional methods and the VDS data on the Joongbu expressway. The density values were compared with those estimated using the vehicular trajectory data in order to evaluate the quality of density estimation. Then, the relationship between the space mean speed and density were drawn using two sets of densities and speeds based on the VDS data and one set of those using the radar detector data. CONCLUSIONS : As a result, the three sets of density showed minor differences when the density values were under 20 vehicles per km per lane. However, as the density values become greater than 20 vehicles per km per lane, the three methods showed a significant difference among on another. The density using the vehicular trajectory data showed the lowest values in general. Based on the in-depth study, it was found out that the space mean speed plays a critical role in the calculation of density. The speed estimated from the VDS data was higher than that from the radar detector. In order to validate the difference in the speed data, the traffic flow models using the relationships between the space mean speed and the density were carefully examined in this study. Conclusively, the traffic flow models generated using the radar data seems to be more realistic.