• Journal of Advanced Marine Engineering and Technology
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• v.39 no.7
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• pp.754-759
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• 2015

Nowadays, short distance communication systems with low power energy (LPE) are developed for identification and monitoring of site identification of vessel crews and passengers (SIVCP). LPE communication modules, such as Bluetooth low energy (BLE) and Zigbee, are used for short distance communications with LPE. These modules enable 1:N communications and their popularity is growing since the modules can be mounted on movable objects, such as mobile devices and human body. When these modules are used, the important factor that affects their operation time and design are the capacity and size of battery. Therefore, they must be made as small as possible, and the battery should be selected to be slightly smaller than the module. In this study, we calculate the theoretical life of batteries used in SIVCP BLE modules using data sheet and discharge characteristic graph under the condition of a 1/250 transmission-ratio (TR). We thus calculate experimental life by measuring transmission current for the same TR, and low speed mode current for a 1/5000 TR and measure long-term experimental life using 1/25 TR for days. Through these experiments, we verify experimental methods for the prediction and extension of battery life that would enable us to select appropriate sizes of batteries based on vessel usage and passenger types. The selections of the module TR and battery size are important factors affecting the cost reduction of module design, the battery maintenance, and passenger convenience.

• Korean Journal of Ecology and Environment
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• v.44 no.2
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• pp.103-112
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• 2011

Aquatic contamination by organic pollutants has been a suspected reason for rapid decrease of amphibian populations whose embryonic and larval stages are in an aquatic environment. Amphibian embryos can be a useful model to study the ecoctoxicologial impacts of aquatic pollutants. The obtained toxicological data are useful references for the management of aquatic pollutants in public health because amphibia share many developmental events with terrestrial vertebrates including humans. Safety guidelines for the toxicological effects of aquatic contaminants of chemicals identified as hazardous should be addressed at multiple endpoints. Alkylphenols have been widely-used in agricultural, industrial, and household activities; they contaminate and can persist in aquatic environments. Exposure to alkylphenols results in endocrine disruption in aquatic animals. In this review, we summarize the developmental toxicities of alkylphenols in amphibian embryos and larva according to the exposure route, chemical concentration, duration of exposure, and affected developmental stage together with mechanisms of toxicity and typical patterns of developmental abnormality. The merits of amphibian embryos as a toxicity test model for mid- to long-term exposure to aquatic pollutants are discussed proposed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.3
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• pp.341-348
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• 2016

Harbor facilities require long-term durability and safety, and also maintain the performance requirement until the durability life. However, existing harbor facilities are becoming superannuated with durable years and durability is declined by erosion of the sea and damage from sea. In addition, harbor facilities will be in demand for the expansion of harbor and offshore structures with rising economic power by enhancement of domestic industry and increase of import and export. Therefore, in this study, two kinds of nondestructive test (NDT) techniques (schmidt rebound hammer and ultrasonic sensor) are verified for the effective maintenance of underwater concrete structures including harbor facilities. Sea field applicability of Schmidt hammer and ultrasonic sensor was verified by comparing field test result with sea field test result and also deduced the compressive strength estimation equation by depth of the water. On the basis of the sea field test result, compressive strength estimation equation which was deduced by multiple regression analysis indicated highest accuracy compared to other equations, especially it will be more likely to be used in underwater because of the depth of water correction. In the future, if schmidt hammer and ultrasonic sensor which were invented as waterproofing are used with ROV (Remotely Operated Vehicle), it will be possible to make a diagnosis of high reliability for underwater concrete structures and set up a ubiquitous concept of NDT system.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.2
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• pp.481-491
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• 2015

Since the crack in the surface of the concrete acts as the main reason influencing the life span of the structure, regular inspections and maintenance are required. The sealing required for maintenance of the concrete surface is a method of repairing the crack in the surface in the beginning, and is effective in preventing additional cracks and expansion that occurs with time. However, sealing on large sized structures such as tall buildings or bottom parts of bridges are difficult to ensure safety of the workers due to inadequate working environments. Due to this reason, the importance of the need for sealing automation for the maintenance of large sized concrete structures is emerging. This study proposes two control methods to apply robot systems to the sealing of cracks on the bottom parts of concrete bridges. First is the method of automatically tracking the trajectory of cracks. The robot gets the trajectory of the cracks using video information obtained from cameras. Comparing the previous several points and new point, the next point can be estimated. Thus, the trajectory of the crack can be tracked automatically. The other method is sealing by maintaining steady force to the contacting surface. The concrete surface exposed to an external environment for a long time gets an irregular roughness. If robots are able to carry out sealing while maintaining a steady contact force on these rough surfaces, complete equal sealing can be maintained. In order to maintain this equal force, a force control method using impedance is proposed. This paper introduces two developed control methods to apply to sealing robots, and conducts a Lab Test and Field Test after applying to a robot. Based on the test results, opinions on the possibilities of field application of the robot applied with the control methods are presented.

• Convergence Security Journal
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• v.21 no.1
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• pp.177-189
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• 2021

Defense R&D is a key process for securing weapons systems determined by mid- and long-term needs to cope with changing future battlefield environments. In particular, the test and evaluation provides information necessary to determine whether or not to switch to mass production as the last gateway to research and development of weapons systems and plays an important role in ensuring performance linked to the life cycle of weapons systems. Meanwhile, if you look at the recent changes in the operational environment of the Korean Peninsula and the defense acquisition environment, you can see three main characteristics. First of all, continuous safety accidents occurred during the operation of the weapon system, which increased social interest in the safety of combatants, and the efficient execution of the limited defense budget is required as acquisition costs increase. In addition, strategic approaches are needed to respond to future battlefield environments such as robots, autonomous weapons systems (RAS), and cyber security test and evaluation. Therefore, in this study, we would like to present strategies for improving the testing and evaluation of weapons systems by considering the characteristics of the security environment that has changed recently. To this end, the improvement strategy was derived by analyzing the complementary elements of the current weapon system operational test and evaluation system in a multi-dimensional model and prioritized through the hierarchical analysis method (AHP).

• Journal of dental hygiene science
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• v.15 no.5
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• pp.569-576
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• 2015

The aim of this study was to assess the oral health knowledge, attitude and behavior among geriatric care workers in long-term care facilities. A self-administered questionnaire was obtained from 212 geriatric care workers attending a professional education program of 2014 dementia pilot project. The questionnaire consisted of 4 parts of the training experience (2 items), knowledge (16 items), attitude (13 items), and behavior (4 items) on oral health care. Collected data were analyzed by frequency analysis, independent t-test, and one-way ANOVA using SPSS Statistics ver. 20.0. The percentage of educational experience on oral care was 27.9% and most respondents answered that they have received the education about denture cleaning (98.3%) and brushing method (91.4%). The average knowledge score was $10.88{\pm}1.70$, and respondents showed high-level agreement in 8 of the 10 items in attitude questions. They revealed difficulties in providing oral care to the elderly people because of their lack of knowledge. The deficiencies of knowledge about oral care would have a decisive effect on not only oral and general health, but also quality of life of the elderly people. Therefore, it is required to develop professional oral care training programs for geriatric care workers and support systems should be legalized.

• Journal of Distribution Science
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• v.14 no.6
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• pp.65-73
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• 2016

Purpose - Recently, the management conditions of small independent retailers are getting worse everyday as large-scale marts and franchised convenience stores are increasing. The objective of this research is to find out the antecedents and consequences of cooperation in voluntary chain in order to enhance small independent retailer's competitiveness. Voluntary chains, also called affiliation or symbol groups, or allied group represent a high market shared in some European countries like Italy, France, and Germany. Nevertheless, there are still limitations in this research from academic fields. Drawing from network theory, the author investigates the relationship between antecedent factors in voluntary chain cooperation, such as participation benefits, justice of compensation, and autonomy in voluntary chain, and relationship specific asset. The author also attempts to examine the relationship between the relationship specific asset and cooperation of voluntary chain member shop and cooperation and consequence factors of voluntary chain cooperation, such as efficiency, group cohesiveness, and long-term relationship. Research design, data, and methodology - The author presented conceptual framework integrating the major antecedents and consequences of voluntary chain cooperation. The data were collected from 174 independent small retailers who joined K-voluntary chain. K-voluntary chain consists of small independent retailers. In accordance with their status, each entrepreneur associated with the voluntary group can own one or more outlets and can be a part of the life and the decision-making process of the group. This participation is not based on company turnover or on the number of outlets, but based on a one member, one vote system. To verify the research model and test hypotheses, the author carefully investigated the reliability, content validity, convergent validity, and discriminant validity of the proposed model. The data were analyzed by using SPSS 18.0 and AMOS structural equation modeling program. Results - The results of this study are as follows. First, as antecedent variables, participation benefits and justice of compensation have positive effect on the relationship specific assets of voluntary chain members. Second, voluntary chain members' relationship specific asset also directly related to the level of its cooperation to chain headquarter. Third, cooperation of voluntary chain member shop facilitates efficiency, group cohesiveness, and long-term relationship. Unexpectedly, there are no effect autonomy in voluntary chain to relationship specific asset. Conclusions - This research shows several theoretical and practical implications to both marketing scholars and marketers. In terms of theoretical implications, this study applies to network theory and network theory variables to explain the antecedent and consequence factors of cooperation in voluntary chain. From the point of view from business management, most of all, this study shows the way how to reinforce competitiveness of voluntary chain. Specifically, it is necessary for voluntary chain headquarter to give higher level of participation benefit and justice of compensation to its members. Second, the results also indicate what the consequence factors of cooperation in voluntary chain. In other words, to increase the level of marketing efficiency, group cohesiveness, long-term orientation in retail voluntary chain, and chain headquarter need to facilitate participants' cooperation.

• Journal of Hospice and Palliative Care
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• v.18 no.1
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• pp.35-41
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• 2015

Purpose: This study was conducted to examine how patients' coping style and social support affect post-traumatic stress disorder (PTSD) in breast cancer patients who are treated with chemotherapy. Methods: The sample consisted of 134 outpatients who received breast cancer treatments at the cancer clinic of a university hospital. The collected data were analyzed by frequency, percentage, t-test, ANOVA, ${\chi}^2$-test, Pearson correlation coefficients using SPSS for Windows, version 18.0. Results: Among total, 26.9% of patients were classified into a high-risk PTSD group. In the high-risk group, a positive correlation was found between active and passive coping styles and between social support and active coping styles. Conclusion: In this study, the stronger the social support was, the more active the coping style was for high-risk PTSD patients with breast cancer. Considering the fact that cancer requires life-long self-management, strong social support could improve patients' healthcare capability. Furthermore, solid social support could effectively reduce the stress level and improve the quality of life for breast cancer patients in the high-risk PTSD group.

• Journal of Life Science
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• v.19 no.11
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• pp.1605-1610
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• 2009

The purpose of this study was to investigate the effects of combined exercise program and garlic pill intake on Body Composition, CRP and Adiponectin in obese high school male students. Twenty-one male students in city B volunteered to participate, and the signed consents were received before the study. Experimental groups were garlic pill intake with combined exercise group (n=7), combined exercise group (n=7), control group (n=7). The total experimental period was 16 weeks. The combined exercise group exercised 3 times a week for 16 weeks with intensity of RPE 7~15. Each exercise was 70 minutes long. A 5 g garlic pill was consumed after lunch and dinner every day. For statistics, two-way repeated test within the group was conducted through SPSS 12.0; for post-examination, Scheffe was utilized; and for inter-group examination, a paired t-test was used. The conclusions of this study are as follows. Between groups, combined exercise with garlic pill group had a significant decrease in %body fat. Within each group, combined exercise with garlic pill group had a significantly greater decrease in %body fat than the control group. Between groups, combined exercise with garlic pill group had a significant decrease in LBM. Between groups, combined exercise with garlic pill group had a significant decrease in CRP. Between groups, combined exercise with garlic pill group, combined exercise and control group showed a decrease in adiponectin. In conclusion, regular exercise and garlic pill intake improved % body fat in obese high school male students.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.3
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• pp.47-56
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• 2020

In this study, three levels of W/B(Water to Binder) ratio (0.37, 0.42, 0.47) and substitution ratio of GGBFS (Ground Granulated Blast Furnace Slag) rate (0 %, 30 %, 50 %) were considered to perform RCPT (Rapid Chloride Diffusion Test) at the 1,095 aged day. Accelerated chloride diffusion coefficient and passed charge of each concrete mixture were assessed according to Tang's method and ASTM C 1202, and improving behaviors of durability performance with increasing aged days are analyzed based on the test results of previous aged days from the preceding study. As the age of concrete increases, the passed charge and diffusion coefficient have been significantly reduced, and especially the concrete specimens containing GGBFS showed a significantly more reduction than OPC(Ordinary Portland Cement) concrete specimen by latent hydraulic activity. In the case of OPC concrete's results of passed charge, at the 1,095 days, two of them were still in the "Moderate" class. So, if only OPC is used as the binder of concrete, the resistance performance for chloride attack is weak. In this study, the time-parameters (m) were derived based on the results of the accelerated chloride diffusion coefficient, and the deterministic and probabilistic analysis for service life were performed by assuming the design variable as a probability function. For probabilistic service life analysis, durability failure probabilities were calculated using Monte Carlo Simulation (MCS) to evaluate service life. The service life of probabilistic method were lower than that of deterministic method, since the target value of PDF (Probability of Durability Failure) was set very low at 10 %. If the target value of PDF suitable for the purpose of using structure can be set and proper variability can be considered for each design variable, it is believed that more economical durability design can be made.