• Journal of Korean Society of Environmental Engineers
• /
• v.36 no.4
• /
• pp.286-294
• /
• 2014

The purpose of this study is to investigate the effects of applying density current generator (hereafter referred to as DCG to large lakes on the operating conditions of DCG, de-stratification, water quality improvement and inhibition of algae occurrence. As a result of a survey conducted to derive the optimum operating parameters of DCG in a condition to minimize eco-toxicity, the following conclusions were obtained. During the survey period, a marked stratification appeared in September to October 2011 and May 2012. At this time, the average depth of water to form thermocline was found to be $5{\pm}2$ m, so the location of discharge port for the operation of DCG was determined to be about 5 m below from the surface. To minimize the adverse effects of benthos and obtain the effect of water mixture at the time of water circulation, the mixing ratio of surface water and deep water was designed to be 3:1 by means of ecotoxicological assessment on the DCG operating characteristics. To select the appropriate operating hours for DCG, DCG was operated by 12 hr, 24 hr, 36 hr and 48 hr. As its result, the formation of thermocline did not occur during the operation of 36 hr. Also, It was effected that start reoperating from 3rd day after stop 2days under the condition of operated during 36 hr with calculated power consumption. Under the above conditions, the results of DO and water temperature analysis during the operation of DCG showed that the stratification, which was distinct previously, appeared to be weak, and relatively lower levels than those before operation were found as a result of water quality analysis on COD and chlorophyll-a, which leads to the conclusion that the water body is maintained at a stable condition due to the circulation of water by the occurrence of density current resulting from the operation of DCG.

• Science of Emotion and Sensibility
• /
• v.21 no.4
• /
• pp.63-76
• /
• 2018

The purpose of this study was to investigate the effect of contact type textile electrode structure on heart activity signal acquisition for smart healthcare. In this study, we devised six contact type textile electrodes whose electrode size and configuration were manipulated for measuring heart activity signals using computerized embroidery. We detected heart activity signals using a modified lead II and by attaching each textile electrode to the chest band in four healthy male subjects in a standing static posture. We measured the signals four times repeatedly for all types of electrodes. The heart activity signals were sampled at 1 kHz using a BIOPAC ECG100, and the detected original signals were filtered through a band-pass filter. To compare the performance of heart activity signal acquisition among the different structures of the textile electrodes, we conducted a qualitative analysis using signal waveform and size as parameters. In addition, we performed a quantitative analysis by calculating signal power ratio (SPR) of the heart activity signals obtained through each electrode. We analyzed differences in the performance of heart activity signal acquisition of the six electrodes by performing difference and post-hoc tests using nonparametric statistic methods on the calculated SPR. The results showed a significant difference both in terms of qualitative and quantitative aspects of heart activity signals among the tested contact type textile electrodes. Regarding the configurations of the contact type textile electrodes, the three-dimensionally inflated electrode (3DIE) was found to obtain better quality signals than the flat electrode. However, regarding the electrode size, no significant difference was found in performance of heart signal acquisition for the three electrode sizes. These results suggest that the configuration method (flat/3DIE), which is one of the two requirements of a contact type textile electrode structure for heart activity signal acquisition, has a critical effect on the performance of heart activity signal acquisition for wearable healthcare. Based on the results of this study, we plan to develop a smart clothing technology that can monitor high-quality heart activity without time and space constraints by implementing a clothing platform integrated with the textile electrode and developing a performance improvement plan.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.23 no.6
• /
• pp.449-469
• /
• 2011

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering during 2010. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) Research trends of thermal and fluid engineering have been surveyed as groups of general thermal and fluid flow, fluid machinery, and new and renewable energy. Various topics were presented in the field of general thermal and fluid flow. Research issues mainly focused on the thermal reliability of axial fan and compressor in the field of fluid machinery. Studies on the design of ground source heat pump systems and solar chemical reactors were executed in the field of new and renewable energy. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics and industrial heat exchangers. Researches on heat transfer characteristics included heat transfer in thermoelectric cooling/power generation systems, combined heat and power systems, carbon nano fluid with PVP, channel filled with metal foam and smoke ventilation in a rescue station of a railroad tunnel. Also the studies on flow boiling of R123/oil mixture in a plain tube bundle and R410A charge amount in an air cooled mini-channel condenser were reported. In the area of industrial heat exchangers, researches on plate heat exchanger, shell and tube heat exchanger, enthalpy exchanger, micro channel PCHE were performed. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics and industrial heat exchangers. Researches on heat transfer characteristics included heat transfer in thermoelectric cooling/power generation systems, combined heat and power systems, carbon nano fluid with PVP, channel filled with metal foam and smoke ventilation in a rescue station of a railroad tunnel. Also the studies on flow boiling of R123/oil mixture in a plain tube bundle and R410A charge amount in an air cooled mini-channel condenser were reported. In the area of industrial heat exchangers, researches on plate heat exchanger, shell and tube heat exchanger, enthalpy exchanger, micro channel PCHE were performed. (3) Refrigeration systems with alternative refrigerants such as hydrocarbons, mixed refrigerants, and CO2 were studied. Performance improvement of refrigeration systems are tried applying various ideas of refrigerant subcooling, dual evaporator with hot gas bypass control and feedforward control. The hybrid solar systems combining the solar collection devices with absorption chillers or compression heat pumps are simulated and studied experimentally as well to improve the understanding and the feasibility for actual applications. (4) Research trend in the field of mechanical building facilities has been found to be mainly focused on field applications rather than performance improvements. Various studies on heating and cooling systems, HVAC facilities, indoor air environments and energy resources were carried to improve the maintenance and management of building service equipments. In the field of heating and cooling systems, papers on a transformer cooling system, a combined heat and power, a slab thermal storage and a heat pump were reported. In the field of HVAC facilities, papers on a cooling load, an ondol and a drying were presented. Also, studies on HVAC systems using unutilized indoor air environments and energy resources such as air curtains, bioviolence, cleanrooms, ventilation, district heating, landfill gas were studied. (5) In the field of architectural environment and energy, studies of various purposes were conducted such as indoor environment, building energy, renewable energy and green building. In particular, renewable energy and building energy-related researches have mainly been studied reflecting the global interest. In addition, many researches which related the domestic green building certification of school building were performed to improve the indoor environment of school.

• Journal of the Korean Applied Science and Technology
• /
• v.37 no.5
• /
• pp.1285-1297
• /
• 2020

In this study, we report the results of a study on the clinical evaluation of wrinkle improvement by developing a method for liposome of high-purity Centella asiatica extract used in pharmaceuticals and cosmetics, and a cream using the same. In order to make Centellasome-10EX stabilizing centella asiatica extract in liposome lamella vesicle, it could be completed using 5% hydrogenated lecithin and 2% sucrose distearate. The appearance of Centellasome-10EX was a creamy form of low viscosity, the color was pale yellow, and the odor had the inherent odor of the raw material. The pH was about 6.12, the specific gravity was 1.09, and the acid value was about 0.35. The content of the main constituents of centella asiatica extract contained in the liposome vesicle contains 10,800 ppm of asiatic acid, 10,900 ppm of asiaticoside, 6,000 ppm of madecasic acid, and 1,600 ppm of madecassoside, and long-term storage. There was no discoloration even at the time, and it was found that the main component remained stable thermodynamically. To mechanistically analyze the structure of the liposome vesicle of Centellasome-10EX, as a result of observation with a transmission electron microscope (Cryo-TEM), the multilayer vesicles are formed and filled with moisture, and there are 10 to 60 multilayers around it. It was confirmed that the liposome lamella vesicle was formed. As a clinical trial (in-vivo) test, the moisturizing effect of centellasome cream after application for 5 weeks was 28.3%, which was significantly increased compared to placebo. The skin elasticity effect was 13.6%, which significantly increased the moisturizing power than the placebo. The effect of improving fine wrinkles around the eyes was improved by 23.52% compared to placebo cream. Through the results of this study, it was possible to study the formulation and manufacturing method for encapsulation and stabilization of the developed Centellasome-10EX in the liposome vesicle. It is expected that the results obtained through clinical research on the wrinkle improvement effect of the cream using this can be widely used to study skin science in the cosmetic industry and to develop high-quality cosmetics with high efficacy.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.47 no.5
• /
• pp.50-60
• /
• 2010

For the last half a century, the personal computer and software industries have been prosperous due to the incessant evolution of computer systems. In the 21st century, the embedded system market has greatly increased as the market shifted to the mobile gadget field. While a lot of multimedia gadgets such as mobile phone, navigation system, PMP, etc. are pouring into the market, most industrial control systems still rely on 8-bit micro-controllers and simple application software techniques. Unfortunately, the technological barrier which requires additional investment and higher quality manpower to overcome, and the business risks which come from the uncertainty of the market growth and the competitiveness of the resulting products have prevented the companies in the industry from taking advantage of such fancy technologies. However, high performance, low-power and low-cost hardware and software platforms will enable their high-technology products to be developed and recognized by potential clients in the future. This paper presents such a platform for industrial embedded systems. The platform was designed based on Telechips TCC8300 multimedia processor which embedded a variety of parallel hardware for the implementation of multimedia functions. And open-source Embedded Linux, TinyX and GTK+ are used for implementation of GUI to minimize technology costs. In order to estimate the expected performance and power consumption, the performance improvement and the power consumption due to each of enabled hardware sub-systems including YUV2RGB frame converter are measured. An analytic model was devised to check the feasibility of a new application and trade off its performance and power consumption. The validity of the model has been confirmed by implementing a real target system. The cost can be further mitigated by using the hardware parts which are being used for mass production products mostly in the cell-phone market.

• Journal of Environmental Policy
• /
• v.6 no.2
• /
• pp.97-122
• /
• 2007

In 2006, the Ministry of Environment of the Republic of Korea, completed the construction on national environmental geographic informations including National Environmental Assessment Map, Ecological Map, Land Cover Map and so on. At this point of time, it is necessary to establish the advance strategy on national environmental geographic information, considering the complicated characteristics. Therefore, this study suggests the advance strategy on national environmental geographic information, reflecting results of analyzing the given condition and the trend of informatization. National environmental geographic information has spacial quality to be managed dispersedly in a department unit or an operations unit. According to this quality, requirements for users who need the policy based on national environmental geographic information and complex information are not satisfactory. And, the information system centering the process of administrative affairs should be converted to one putting decision supporting first in importance. Therefore, this study sets up "the realization of the sustainable land management system by advancing national environmental geographic information" as the vision of the advancing strategy. In order to accomplish the vision, this study established the purpose as follow; constructing strategic and geographic information based on knowledge, arranging the foundation to open information to the public transparently, building expanded and integrated national environmental geographic information, embodying the environmental administration based on national environmental geographic information, enhancing the efficiency of national environmental geographic information, and supporting efficiently the process of administrative affairs. And this study suggests executive plans to achieve the vision and the purpose as next; developing the quality control program to verify the information confidence, building the system to integrate and to provide environmental information, collecting information, readjusting laws and regimes in parts of the construction, the application and the management of the system, and operating the task process, human power, organization and information technology. This study puts the emphasis on providing the turning opportunity politically which is possible to make sure of the information confidence in quality, advancing from the expansion of one in quantity. However, this improvement strategy doesn't reflect all national environmental geographic information and current status of environmental administrations. Therefore, for applying the result of this study to the actual environmental administration, it is necessary to discuss regularly the systematic categorization of national environmental geographic information, to interview with the contracting parties and so on hereafter.

• Asia pacific journal of information systems
• /
• v.20 no.3
• /
• pp.139-166
• /
• 2010

The supply chain management (SCM) systems have emerged as strong managerial tools for manufacturing firms in enhancing competitive strength. Despite of large investments in the SCM systems, many companies are not fully realizing the promised benefits from the systems. A review of literature on adoption, implementation and success factor of IOS (inter-organization systems), EDI (electronic data interchange) systems, shows that this issue has been examined from multiple theoretic perspectives. And many researchers have attempted to identify the factors which influence the success of system implementation. However, the existing studies have two drawbacks in revealing the determinants of systems implementation success. First, previous researches raise questions as to the appropriateness of research subjects selected. Most SCM systems are operating in the form of private industrial networks, where the participants of the systems consist of two distinct groups: focus companies and vendors. The focus companies are the primary actors in developing and operating the systems, while vendors are passive participants which are connected to the system in order to supply raw materials and parts to the focus companies. Under the circumstance, there are three ways in selecting the research subjects; focus companies only, vendors only, or two parties grouped together. It is hard to find researches that use the focus companies exclusively as the subjects probably due to the insufficient sample size for statistic analysis. Most researches have been conducted using the data collected from both groups. We argue that the SCM success factors cannot be correctly indentified in this case. The focus companies and the vendors are in different positions in many areas regarding the system implementation: firm size, managerial resources, bargaining power, organizational maturity, and etc. There are no obvious reasons to believe that the success factors of the two groups are identical. Grouping the two groups also raises questions on measuring the system success. The benefits from utilizing the systems may not be commonly distributed to the two groups. One group's benefits might be realized at the expenses of the other group considering the situation where vendors participating in SCM systems are under continuous pressures from the focus companies with respect to prices, quality, and delivery time. Therefore, by combining the system outcomes of both groups we cannot measure the system benefits obtained by each group correctly. Second, the measures of system success adopted in the previous researches have shortcoming in measuring the SCM success. User satisfaction, system utilization, and user attitudes toward the systems are most commonly used success measures in the existing studies. These measures have been developed as proxy variables in the studies of decision support systems (DSS) where the contribution of the systems to the organization performance is very difficult to measure. Unlike the DSS, the SCM systems have more specific goals, such as cost saving, inventory reduction, quality improvement, rapid time, and higher customer service. We maintain that more specific measures can be developed instead of proxy variables in order to measure the system benefits correctly. The purpose of this study is to find the determinants of SCM systems success in the perspective of vendor companies. In developing the research model, we have focused on selecting the success factors appropriate for the vendors through reviewing past researches and on developing more accurate success measures. The variables can be classified into following: technological, organizational, and environmental factors on the basis of TOE (Technology-Organization-Environment) framework. The model consists of three independent variables (competition intensity, top management support, and information system maturity), one mediating variable (collaboration), one moderating variable (government support), and a dependent variable (system success). The systems success measures have been developed to reflect the operational benefits of the SCM systems; improvement in planning and analysis capabilities, faster throughput, cost reduction, task integration, and improved product and customer service. The model has been validated using the survey data collected from 122 vendors participating in the SCM systems in Korea. To test for mediation, one should estimate the hierarchical regression analysis on the collaboration. And moderating effect analysis should estimate the moderated multiple regression, examines the effect of the government support. The result shows that information system maturity and top management support are the most important determinants of SCM system success. Supply chain technologies that standardize data formats and enhance information sharing may be adopted by supply chain leader organization because of the influence of focal company in the private industrial networks in order to streamline transactions and improve inter-organization communication. Specially, the need to develop and sustain an information system maturity will provide the focus and purpose to successfully overcome information system obstacles and resistance to innovation diffusion within the supply chain network organization. The support of top management will help focus efforts toward the realization of inter-organizational benefits and lend credibility to functional managers responsible for its implementation. The active involvement, vision, and direction of high level executives provide the impetus needed to sustain the implementation of SCM. The quality of collaboration relationships also is positively related to outcome variable. Collaboration variable is found to have a mediation effect between on influencing factors and implementation success. Higher levels of inter-organizational collaboration behaviors such as shared planning and flexibility in coordinating activities were found to be strongly linked to the vendors trust in the supply chain network. Government support moderates the effect of the IS maturity, competitive intensity, top management support on collaboration and implementation success of SCM. In general, the vendor companies face substantially greater risks in SCM implementation than the larger companies do because of severe constraints on financial and human resources and limited education on SCM systems. Besides resources, Vendors generally lack computer experience and do not have sufficient internal SCM expertise. For these reasons, government supports may establish requirements for firms doing business with the government or provide incentives to adopt, implementation SCM or practices. Government support provides significant improvements in implementation success of SCM when IS maturity, competitive intensity, top management support and collaboration are low. The environmental characteristic of competition intensity has no direct effect on vendor perspective of SCM system success. But, vendors facing above average competition intensity will have a greater need for changing technology. This suggests that companies trying to implement SCM systems should set up compatible supply chain networks and a high-quality collaboration relationship for implementation and performance.

• Journal of the Korean Society of Earth Science Education
• /
• v.4 no.3
• /
• pp.278-296
• /
• 2011

The purpose of this study is to examine the pedagogical content knowledge (PCK) elements and the changes in the science lesson planning and implementation difficulties experienced by high-career elementary school teachers with over 20 years of educational experience through the instructional consulting case of the Seoul City Office of Education Scholarship Support Group in order to find implications on effective instructional consulting support plan for improving the science teaching professionalism of high-career elementary school teachers. The result of this study is as follows : First, the pedagogical content knowledge (PCK) elements on the science lesson planning and implementation difficulties experienced by high-career elementary school teachers with over 20 years of educational experience were related to teaching strategy and they experienced difficulties in lesson content organization using lesson model and experiment facilitation and questioning, as well as in the area of interest and motive management that are definitional characteristic of learner in the learner element. Second, as for the changes in the PCK through science instructional consulting, they recognized the importance of the designing and experimenting process as students become the subject in the experiment facilitation in lesson, and they ended up attempting the postscript for promoting the thinking power of students. In addition, it was found that not only the cognitive characteristic but also the definitional characteristic of learner is important in science lesson and that students' motive is also an element that needs to be continuously managed. Third, as for effective instructional consulting plan for enhancing the science teaching professionalism of high-career elementary school teachers, it was revealed that it is necessary to first develop lesson expertise improvement consulting program that takes into account of teaching profession advancement phase of high-career teachers, and establish instructional consulting system and human resource pool of high-quality consultants based on the administrative and financial support from the Office of Education. The academic significance of this study is in the fact that it examined and searched for support plan on science teaching professionalism of high-career elementary school teacher, but a more extensive and in-depth study is needed since there is a limitation in this study on the object of study and the period.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.26 no.4
• /
• pp.985-994
• /
• 2016

Since the inauguration of Defense Acquisition Program Administration(DAPA) in 2006, the national defense core technology research & development business has not only pertained to the weapons systems development but also to the improvement of the national science & technology capability via the acquisition of cutting-edge technologies. Furthermore, it has been closely related to the promotion of the defense industry and the mutual improvements of defense and civil technologies. The cyber warfare weapon system, a newly added national defense weapon system field since 2015, has become a promising weapon system branch for improving the national defense power as well as the national defense industry as shown in the case of Israel. By utilizing the existing result of the national defense core technology level, in order to establish the direction of technology planning of the cyber warfare weapon system, this paper analyzes the technology level and features of the cyber warfare weapon system in various aspects via comparisons with other weapons systems. The result of these analyses shows that the cyber warfare weapon system possesses a relatively high technology level due to the technology accumulation in the civilian sector while the relatively slow inclusion to the national weapons systems and the lack of the correspondence case regarding aggressive cyber responses in the defense sector yields a relatively low national rank. However, the technological gap between South Korea and the most advanced country in the field of cyber warfare technology is analyzed to be among the lowest, which indicates that with efficient and effective pursuits in terms of pthe weapons systems acquisitions as well as the core technologies research & development business, an outstanding cyber warfare capacity can be obtained in a short time.

• Journal of Korean Neurosurgical Society
• /
• v.47 no.5
• /
• pp.345-351
• /
• 2010

Objective : In this study, the Mindfulness Based Stress Reduction (MBSR) program was applied to patients presenting with depression and anxiety after surgery from spontaneous subarachnoid hemorrhage (SAH) and the effects were assessed. Methods : The subjects were patients admitted for cerebral aneurysm rupture and treated by means of surgery from March to December, 2007. More than 6 months had passed after surgery, without any special lesions showing up on computed tomography (CT), and the Glasgow outcome scale (GOS) was 5 points. Among patients with anxiety and depression symptoms, 11 patients completed the program. The MBSR program was conducted once a week, 2.5 hours each, for 8 weeks. The evaluation criteria were : 1) the Beck Depression Inventory (BDI): it measures the type and level of depression, 2) the State-Trait Anxiety Inventory : the anxiety state of normal adults without mental disorder, and 3) Heart Rate Variability (HRV) : the influence of the autonomous nervous system on the sinoarterial node varies continuously in response to the change of the internal/external environment. Results : The BDI value was decreased from 18.5 ${\pm}$ 10.9 to 9.5 ${\pm}$ 7.1 (p = 0.013) : it was statistically significant, and the depression level of patients was lowered. The state anxiety was decreased from 51.3 ${\pm}$ 13.9 to 42.3 ${\pm}$ 15.2; the trait anxiety was reduced from 50.9 ${\pm}$ 12.3 to 41.3 ${\pm}$ 12.8, and a borderline significant difference was shown (p = 0.091, p = 0.056). In other words, after the treatment, although it was not statistically significant, a decreased tendency in anxiety was shown. In the HRV measurement, standard deviation normal to normal (SDNN), square root of the square root of the mean sum of squared differences between adjacent normal to normal intervals (RMSSD), and total power (TP) showed significant increase, Physical Stress Index (PSI) showed a significant reduction, and thus an improvement in the homeostatic control mechanism of the autonomic nervous system was ween. Conclusion : The MBSR program was applied to the patients showing anxiety and depression reaction after SAH treatment, and a reduction in depression symptoms and physiological reactions were observed. The application of the MBSR program may be considered as a new tool in improving the quality of life for patients after surgery.