• Journal of Korea Water Resources Association
• /
• v.53 no.11
• /
• pp.1015-1024
• /
• 2020

Recently, water pollution accidents have continued to occur in pipelines such as red water Incheon and Seoul. In order to recognize this water quality problem, it is necessary to install a water quality sensor in an appropriate location and measure it in advance to detect or block the water supply to the water faucet of the shelter. However, there are limitations, such as maintenance costs, to installing multiple water meters in all pipelines. Therefore, this study proposed a methodology for determining and prioritizing the installation location of flow-based water quality sensor for the recognition of water quality problems in pipelines. We applied the proposed procedure to the pipe break scenario. The results of the determination of the location of the water quality sensor were presented by applying it to the pipe network that actually operates the emergency pipe in Korea. The result of the decision showed that in the event of abnormal situation caused by the destruction of individual pipes, the flow rate of the pipes around the aqueduct and the tank may change rapidly, resulting in water quality accidents caused by turbidity. In the future, it is expected that the water quality monitoring point selection method, such as establishing an external pipe operation plan for pipe cleaning, will utilize the procedure for determining the location of the water quality sensor according to the velocity.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.9 no.3
• /
• pp.47-57
• /
• 2007

This study focused on the properties natural dyeing and natural material and on the development of functional material for well-being in apparel industry. Comus officinalis Siebold et Zuccarini is used as natural dyeing material which had been reported that have curable effect for unbalanced immunity, geriatric diseases like urinary tract system, diabetes, hypertension, arthritis, tinnitus, hyperhidrosis and women's diseases like hypermenorrhea. And this material also has anti-cancer effect so that can restraint cancer cells. 3 kinds tester of cotton, wool and silk are dyed by boiled with each dye (flower, fruits, bark of tree) as first dyeing and dried in the shade. These testers are done by post-mordanting method. Aluminium Potassium(Alk(SO4)2), Cuprie Sulfate($CuSO4{\cdot}5H2O$), Stannous Chloride($SnCl2{\cdot}2H2O$), Ferrous Sulfate($FeCl2{\cdot}4H2O$), Titanium Sulfate 24% aqueous solution(Ti(SO4)2) are used as mordants. Dyeing results of Comus officinalis Siebold et Zuccarini flower and bark are shown as yellow color series. And dyeing result of fruits is pink color series. Silk shows the best dyeing property. As the point of view for dyeing property, Ti, Sn, Fe would be the properchoice for mordant. Following results are extracted in this study. Yellow color is resulted in dyeing with Cornus officinalis flower as non-mordanting condition. Yellowish red color is come from dyeing with Comus officinalis fruit as non-mordanting condition. Grayish yellow tone is resulted in dyeing with bark as non-mordanting condition. Orange tone color with Ti-mordanting, green tone color with Sn-mordanting and gray tone color with Fe-mordanting is resulted respectively. However light-fastness of Comus officinalis(flower, fruit, bark) is very low as 1 or 2 level in non-mordanting condition, Comus officinalis flower dyeing is turned out 3 or 4 level and fruit dyeing is 4 or 5 level, bark dyeing is 2 or 3 level with Ti-mordanting respectively. Eventually Comus officinalis fruit has the best light-colorfastness property among all of dyes. dry cleaning colorfastness of Cornus officinalis(flower, fruit, bark) is good as 4 or 5 level in Ti-mordanting condition, perspiration-colorfastness of Cornus officinalis(flower, fruit, bark) is good as 4 or 5 level in Ti-mordanting condition, With these results, this study could conclude that dye-ability, colorfastness problem is getting better after mordanting process and practical usage would be possible.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.36 no.3
• /
• pp.158-167
• /
• 2020

Purpose: The purpose of this study was to study the effects of the utilization of ethanol solution in infection control of dental implant hand drivers, a common practice in dental prosthodontic clinics. Materials and Methods: Infection control methods were divided into two groups. One swabbed with 83% ethanol gauze and the other immersed in 83% ethanol solution for 30, 60, 90, 120, 150, 180 and 300 second intervals after inoculation of the dental implant hand drivers with Staphylococcus aureus. After measuring the number of colony forming units and analyzing the optical density, the effects of infection control in the experimental group were compared with the positive control group without infection control after inoculation with bacteria and the negative control group without inoculation with bacteria after sterilization. Results: The number of colony forming units and optical density analysis showed a statistically significant difference compared to the positive control. On the other hand, there was no statistically significant difference between the negative control and the group immersed in the 83% ethanol solution for more than 150 seconds. Conclusion: It is recommended to use the ethanol solution as a pre-cleaning process before sterilization, since the intermediate-level disinfection method using ethanol solution alone for the infection control of the dental implant hand driver cannot clinically secure the sterility.

• Journal of the Korean Institute of Rural Architecture
• /
• v.17 no.3
• /
• pp.55-62
• /
• 2015

Recently as return farmers has been increased rapidly, the introduction of a system of rental housing is being considerated in order to induce regional fixation. It was examined organizational management, business scope of rural type rental housing, management role, through the analysis about the management realities of the business of similar form Rural-Fishing New Town project. Jangseonggun and Hwasungun have maneged rental housing 280ho in Rural-Fishing New Town project. It is large village among Rural Rental Housing. And these counties have organized the complex on a large scale among the rental housing. Local governments have managed and operated directly, also these governments have two different methods for the co-management, and the way of making payment. Rental housing management services are divided into rental management, housing management, tenant management. Rental management services such as residents of recruitment, tenants and retreat, rent collection and the storage, management and leasing promotion of the cantilever, surveys of residents. Housing management services such as check of various facilities, maintenance and maintenance work, security and cleaning and daily facility management. Tenant management is life management in connection with housing welfare. In the rural type of rental housing, there are few cases to operate a management office. It is often supplied by rental housing to buy a house or vacant land within the existing village. In this case, by utilizing community facilities within the existing village instead of establishment of extra facilities,It doesn't need to make payment for maintenance fee. In the smaller complex than No. 20, it is self-managed by the tenants in order to reduce the administrative costs and specify the necessary municipal manager. Organization form can be maneged directly from local governments and part of for the management of the building can be employed a mixed management system to delegate management to private organizations such as non-profit organizations or neighborhood association. Tenant management helps people who move in a rental house live on stable circumstance in there area by connection with the program of life support.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.4
• /
• pp.1824-1832
• /
• 2011

In this paper, a smart home service robot McBot II is newly developed in much more practical and intelligent system than McBot I which we had developed a few years ago. Thus far, vacuum-cleaners have lightened the burden of household chores but the operational labor that vacuum-cleaners entail has been very severe. Recently, a cleaning robot was commercialized to solve but it also was not successful because it still had the problem of mess-cleanup, which pertained to the clean-up of large trash and the arrangement of newspapers, clothes, etc. Hence, we develop a new home mess-cleanup robot McBot II to completely overcome this problem on real environments. The mechanical design and the basic control of McBot II, which performs mess-cleanup function etc. in house, is actually focused in this paper. McBot II is mechanically modeled in the same method that the human works in door by using the waist and the hands. The big-ranged vertical lift and the shoulder joints to be able to forward move are mechanically designed for the operating function as the human's waist when the robot works. The mobility of McBot II is designed in the holonomic mobile robot for the collision avoidance of obstacle and the high speed navigation on the small area in door. Finally, good performance of McBot II, which has been optimally desinged, is confirmed through the experimental results for the control of the robotic body, mobility, arms and hands in this paper.

• Journal of Distribution Science
• /
• v.13 no.1
• /
• pp.105-118
• /
• 2015

Purpose - The objective of this study is to verify whether there are differences between Korean and Chinese consumers in the importance of the attributes such as shopping value and loyalty in social commerce. With the purpose of finding out these differences, the following questions are set up as research questions. First, will there be a difference between Korea and China in the importance of attributes of social commerce? Second, will there be a difference between Korean and Chinese consumers in shopping value? Third, will there be a difference between Korean and Chinese consumers in their loyalty? Research design, data, and methodology - The researchers collected data through self-administered questionnaires from Korean and Chinese consumers who had used social commerce within the past six months before answering the questionnaire. First, for social commerce users in Korea, comprising male and female university students in Chungcheong, a questionnaire was circulated. For social commerce users in China, university students within Beijing were surveyed. Responses to 336 questionnaires were used, excluding those with no answers or unreliable answers. Data coding and data cleaning were used. SPSS 18.0 was used. First, exploratory factor analysis is done to verify the validity of testing tools, and Cronbach's α coefficient is used to verify credibility. For factor analysis, the Varimax method is used. To verify the internal consistency reliability of each factor, the Cronbach's α coefficient is used to verify the credibility. Second, a T-test is done to verify differences between Korean and Chinese consumers for the importance of attributes. Third, ANOVA (Analysis of variance) is done to verify differences between Korean and Chinese consumers in shopping value and loyalty. Results - When Korean and Chinese consumers use social commerce, first, the importance of the attributes of social commerce is affected by four factors; playfulness and economic factors are more important to Korean consumers than Chinese consumers. As for informativeness factors, including product information and quality, and buyer comments, there was no confirmed difference between Korean and Chinese consumers. The convenience factor is more important to Chinese consumers than Korean consumers. Second, the factors affecting shopping value for Korean and Chinese consumers were hedonic shopping value and rational shopping value. To see the difference between Korean and Chinese consumers in shopping value factors, a t-test is conducted. As a result, in the rational shopping value factors of social commerce, Korean consumers scored higher than did Chinese consumers. These results were verified to be meaningful through statistics. In the hedonic shopping value factor of social commerce, Korean consumers scored higher than Chinese consumers. These results showed a significant difference. Third, loyalty in social commerce is higher for Chinese consumers than for Korean consumers. However, there is no difference in loyalty depending on sex. Conclusions - These results will hopefully be valuable and used in the future by Korean companies that wish to enter the Chinese social commerce market.

• Journal of Distribution Science
• /
• v.13 no.1
• /
• pp.47-55
• /
• 2015

Purpose - The objective of this study is to verify whether there are differences between Korean and Chinese consumers in the importance of the attributes such as shopping value and loyalty in social commerce. With the purpose of finding out these differences, the following questions are set up as research questions. First, will there be a difference between Korea and China in the importance of attributes of social commerce? Second, will there be a difference between Korean and Chinese consumers in shopping value? Third, will there be a difference between Korean and Chinese consumers in their loyalty? Research design, data, and methodology - The researchers collected data through self-administered questionnaires from Korean and Chinese consumers who had used social commerce within the past six months before answering the questionnaire. First, for social commerce users in Korea, comprising male and female university students in Chungcheong, a questionnaire was circulated. For social commerce users in China, university students within Beijing were surveyed. Responses to 336 questionnaires were used, excluding those with no answers or unreliable answers. Data coding and data cleaning were used. SPSS 18.0 was used. First, exploratory factor analysis is done to verify the validity of testing tools, and Cronbach's α coefficient is used to verify credibility. For factor analysis, the Varimax method is used. To verify the internal consistency reliability of each factor, the Cronbach's α coefficient is used to verify the credibility. Second, a T-test is done to verify differences between Korean and Chinese consumers for the importance of attributes. Third, ANOVA (Analysis of variance) is done to verify differences between Korean and Chinese consumers in shopping value and loyalty. Results - When Korean and Chinese consumers use social commerce, first, the importance of the attributes of social commerce is affected by four factors; playfulness and economic factors are more important to Korean consumers than Chinese consumers. As for informativeness factors, including product information and quality, and buyer comments, there was no confirmed difference between Korean and Chinese consumers. The convenience factor is more important to Chinese consumers than Korean consumers. Second, the factors affecting shopping value for Korean and Chinese consumers were hedonic shopping value and rational shopping value. To see the difference between Korean and Chinese consumers in shopping value factors, a t-test is conducted. As a result, in the rational shopping value factors of social commerce, Korean consumers scored higher than did Chinese consumers. These results were verified to be meaningful through statistics. In the hedonic shopping value factor of social commerce, Korean consumers scored higher than Chinese consumers. These results showed a significant difference. Third, loyalty in social commerce is higher for Chinese consumers than for Korean consumers. However, there is no difference in loyalty depending on sex. Conclusion - These results will hopefully be valuable and used in the future by Korean companies that wish to enter the Chinese social commerce market.

• Resources Recycling
• /
• v.30 no.5
• /
• pp.38-48
• /
• 2021

In this study, we determine the optimal process conditions for selectively recovering Si from a solar cell surface by removal of impurities (Al, Zn, Ag, etc.). To selectively recover Si from solar cells, leaching is performed using HCl solution and an ultrasonic cleaner. After leaching, the solar cells are washed using distilled water and dried in an oven. Decompression filtration is performed on the HCl solution, and ICP-OES (Inductively Coupled Plasma Optical Emission spectroscopy) full scan analysis is performed on the filtered solution. Furthermore, XRD (X-ray powder diffraction), XRF (X-ray fluorescence), and ICP-OES are performed on the dried solar cells after crushing, and the purity and recovery rate of Si are obtained. In this experiment, the concentration of acid solution, reaction temperature, reaction time, and ultrasonic intensity are considered as variables. The results show that the optimal process conditions for the selective recovery of Si from the solar cells are as follows: the concentration of acid solution = 3 M HCl, reaction temperature = 60℃, reaction time = 120 min, and ultrasonic intensity = 150 W. Further, the Si purity and recovery rate are 99.85 and 99.24%, respectively.

• Journal of vocational education research
• /
• v.36 no.2
• /
• pp.23-50
• /
• 2017

The purpose of this study was to determine the hierarchical linear relationship among receptivity to organizational change, individual variables of professors and organizational variables in junior colleges. The population for this study was 12,920 professors in 139 junior colleges. Using random sampling method considering subject, 800 professors in 40 colleges were sampled for this study. The data were collected from May 26 to June 13. A total of 445 out of 800 questionnaires were returned of which 441 of 40 junior colleges were used for analysis after data cleaning. These data were analyzed by both descriptive statistics and One-way ANOVA with Random Effects, Ranmdom-Coefficients Regression Model, and Intercepts-and Slopes-as-Outcomes Model of hierarchical linear model(HLM). All data analysis was accomplished using the SPSS 20.0 for windows program and the HLM 6.0 for windows program. An alpha level of 0.05 was established priori for determining the significance. The findings of the study were as follows: First, the level of receptivity to organizational change of professions in junior college was 3.94. Second, 56.5% of total variance in receptivity to organizational change was individual level variance. 43.5% of total variance in receptivity to organizational change was organizational level variance. Third, personal valence about organizational change, psychological ownership, experience of assignment, years of service and job security had positive effects on receptivity to organizational change while years of service had negative effects on receptivity to organizational change. The effect of personal valence about organizational change was highest, and the effect of job security was lowest. Fourth, degree of organizational change, participative decision-making, group culture and accessibility of information related to organizational change had positive effects on receptivity to organizational change. The effect of degree of organizational change was highest, and the effect of accessibility of information related to organizational change was lowest.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.2
• /
• pp.378-385
• /
• 2021

The production of plum jangachi requires the cleaning of plums, immersion in saltwater, separation of seed and pulp, removal of impurities, and addition of sugar. In most farms, the separation of plum seed and pulp is carried out manually, requiring considerable labor, which is why plum jangachi is expensive. To solve this problem, this study designed and manufactured automatic, semi-automatic plum seed and pulp separators. During the design process, the characteristics were compared, and the machine power was determined through on-site test after manufacture. As a result, automatic machines used plums 180° arrayed and six reverse-edged blades, semi-automated plums 180° arrayed, and six blades, each with a 68% and 57% pulp recovery rate and a machine power of 80 kg/h and 62 kg/h respectively. Overall, the mechanization of plum processed food will reduce labor and increase the market value of plums compared to the previous method.