• Journal of Bio-Environment Control
• /
• v.26 no.4
• /
• pp.353-360
• /
• 2017

In this study, the design and performance test of the air to water heat pump capable of producing hot water for greenhouse heating by using the surplus solar heat inside the greenhouse and the air heat outside greenhouse as the selective heat source were conducted. The heat storage operations using the surplus solar heat and the outside air heat were designed to be switched according to the setting temperature of the greenhouse in consideration of the optimum temperature range of the crop. In the developed system, it was possible to automatically control the switching of heat storage operation, heating and ventilation by setting 12 reference temperatures on the control panel. In the selective heat storage operation with the surplus solar heat and outside air heat, the temperature of thermal storage tank was controlled variably from $35^{\circ}C$ to $52^{\circ}C$ according to the heat storage rate and heating load. The heat storage operation times using the surplus solar heat and outside air heat were 23.1% and 30.7% of the experimental time respectively and the heat pump pause time was 46.2%. COP(coefficient of performance) of the heat pump of the heat storage operation using the surplus solar heat and outside air heat were 3.83 and 2.77 respectively and was 3.24 for whole selective heat storage operation. For the comparative experiment, the heat storage operation using the outside air heat only was performed under the condition that the temperature of the thermal storage tank was controlled constantly from 50 to $52^{\circ}C$, and COP was analyzed to be 2.33. As a result, it was confirmed that the COP of the heat storage operation using the surplus solar heat and outside air heat as selective heat source and the variable temperature control of the thermal storage tank was 39% higher than that of the general heat storage operation using the outside air heat only and the constant temperature control of the thermal storage tank.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.6 no.1
• /
• pp.1-11
• /
• 1986

Welded connectors of the cover plates, the transverse stiffeners of the plate girders, and the gusset plates of the plates girders or box girders, were selected as studying objects. A simplified method of drawing the S-N curves in these welded joints by a computer program without the direct fatigue tests was established. The plots on the S-N curve using the values from the practical fatigue tests were compared with the results from the method of the computer programming. The results of these studies are as follows. It appeared that the fatigue life by calculation method was a little less than the practical fatigue life from the actual tests. The latter values included both life $N_c$ of occurrence of initial crack $a_i$ and the life $N_p$ of propagation of critical crack. On the other hand, the former values included only the life $N_p$. Therefore, these results should be considered as justifiable ones. Since the difference between the two results was not significant, the results by calculation method should be in the conservation side when the safety of the structures was considered. Consequently, the results by calculation method should be applicable to the fracture fatigue design of structure. For reference, the same fatigue tests were performed with the specimens of 3 pieces in each case made of the low-strength steel, SS 41. The results went unexpected showing that the fatigue strength was lower in the case of low-strength steel. That is, in the case of the cover plate, the fatigue strength became slowly higher than the case of high-strength steel, SWS 50. That was observed when the maximum testing stress was higher than $14kg/mm^2$. In addition, in the case of the transverse stiffener, the fatique strength became rapidly higher than the case of SWS 50. That was observed when the maximum testing stress was lower than $31kg/mm^2$. It was thought that more such fatigue tests should be performed for more reliable results.

• Journal of Korean Society of Forest Science
• /
• v.97 no.1
• /
• pp.61-70
• /
• 2008

This study was conducted to develop a mobile tower-yarder with tractor for agriculture and forestry that is the efficient yarder in steep terrains, thinning operation and small scale logging operation. It was designed and manufactured that the power source of tower-yarder is equiped three hydraulic pump connected to PTO of tractor, and three hydraulic pump is used to operate the four motor for drum, the cylinder for clutch of interlocker, the cylinder for tower expanding and the out-rigger cylinder. It was to adopt the running skyline system and the inter-lock function, and to equip the double capstan drum, the storage drum and the clutch for interlock in the development of tower-yarder. It was to develop the tower-yarder which the winch torque of double-capstan drum, the traction force of double-capstan drum, the number of rotation of double-capstan drum and the line speed is $191kg{\cdot}m$, 1,910 kgf, 220.5 rpm and 138.5 m/min, respectively. And it was known that the optimum flange diameter of the main and haulback storage drum is about 360 mm and about 460 mm in order to storage the main line length of 250m and the haulback line length of 450 m. The carriage was made to adopt the running skyline system and to equip the lock function in order to the convenience of chocking and the fall down preventing of tree. It was provided to develop the wire remote controller for the inter-lock function, the convenience of control and the efficiency of yarding. In development process, this tower-yarder was attached the 3-point linkage hitch equipment and the tire wheel for the traction and moving of tower-yarder. Also, it was equipped that the out-rigger and the guy line in order to raise the safety and efficiency of yarding of tower-yarder.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.41 no.6
• /
• pp.96-106
• /
• 2013

The aim of this study was to reveal the advantages and disadvantages of Terelj Mongolian National Park based on the impressions of foreign and domestic travelers, and subsequently suggest supporting ideas to make this tourist attraction more enjoyable for travelers. A statistical program(SPSS 20.0) and an IPA matrix method were used to reveal the impressions of travelers and the results showed the following ideas. First, we made the technical analyses to demonstrate the characteristics of the current natural scenery which travelers want to see and the results indicated that both Korean and Mongolian travelers overall were not satisfied and the Park was not as they had imagined. The second part of the research highlighted the differences between the impressions held by Mongolian and Korean travelers, which showed dissimilarities in cultural resources, food, variety of events, cultural functions and parking, all of which were shown as important criteria in sightseeing. The variations were found in scenes of nature, variety of programs, and food, areas which revealed and were very important in the overall satisfaction of travelers. Third, the IPA method was used for analyze the advantages and disadvantages of Terelj National Park. The Mongolian travelers nominated the width of the road, cleanliness, variety of events and parking are the most essential things to feel satisfied, but Koreans selected safety of travel, accommodation, the width of the road and cleanliness. Finally, we analyzed the feelings of the travelers at the end of their trip. The Mongolian travelers preferred the area resource and environment convenience to feel satisfaction. For Korean travelers, the area resource is the most important when choosing travelling sights. Based on these results, if we take responsibility to protect the beauty of nature, and create a sightseeing place using natural sources, while also making more comfortable accommodations and improving the services, it can be a more unique place than others and lead to greater overall satisfaction for travelers.

• Herbal Formula Science
• /
• v.13 no.2
• /
• pp.1-16
• /
• 2005

Objectives: To find out the effects GGTl, an antiobestic drug widely used in clinics, has on the blood-antiobestic index and the toxicity index using the data from the hGHTg obese male rats. We looked closely into both of the two indices because GGTl antiobestic effect can happen not only by pharmacological action, but also by its toxicity. Also, we verified the difference in effect between GGTl and reductil (sibutramine), which has been approved by the FDA of the United States. Methods: After performing the experiments for 8 weeks on the hGHTg obese male rats divided into three groups: the control group, the GGTl group, and the reductil (RD) group, we anesthetized the rats with Diethyl ether and took a 3ml blood sample from the heart. Then, after coagulating the blood in room temperature by using the plasma separator, we centrifuged it for 25 minutes in 3,000rpm using the high-speed refrigerated centrifuge. We kept the separated plasma in a deep freezer at $-80^{\circ}C$, and repeatedly measured the antiobestic index and the toxicity index twice using the hematology biochemistry analyzer. Also, in order to judge the indirect toxicity index, we separated liver from kidney and observed them. Results: When we looked at the results of the analysis of covariance on the measuring elements related to the antiobestic index (TC, HDL, LDL, TG, and GLU), there was no significant difference among the groups in all measuring elements. Also, the results of the analysis of covariance on the two roups (RD group and GGTl group) showed that the p-values had no significant difference under the level of significance 0.05. When we looked at the result of the analysis of covariance on the measuring elements related to the toxicity index (GOT, GPT, GGT, CREA, UA, ALB, and TP), we could see that the p-values in GPT, ALB, and TP have a significant difference among the groups. Also, the results of the analysis of covariance about the measuring elements related to the toxicity index on both groups, RD group and GGTl group, showed no significant difference in the p-values of all of the measuring elements in the two groups, RD and GGTl group. Conclusions: In conclusion, through this experiment, the safety of GGTl has been approved, and although the verification on its medical effect has not been clearly approved, when we consider the fact that it belongs to the same group as reductil, an antiobestic drug approved by the FDA of the United States, we could indirectly verify that GGTl has an antiobestic effect. We believe that when doing a sample design for a future experiment, it needs to be performed on a greater sample size based on the power analysis that needs to be performed primarily in experiments, and a more accurate verification is needed through more systematic experiment plans.

• Journal of the Society of Disaster Information
• /
• v.16 no.1
• /
• pp.163-177
• /
• 2020

Purpose: While it is very important to maintain facilities recently, the introduction and its application of high technology in the facility maintenance industry has increased. It is necessary for high technology to secure reliability through the verification and certification system of diagnostic equipment to have an effective impact in the field, but there is difference between the industry's perspective and realistic level of technology apart from social demand for the system of the system. This paper dealt with the introduction of a verification and certification system for rational facility diagnostic equipment with the opinion survey on managers about the current situation. Method: Survey is carried out targeting managers in the maintenance and construction regarding the necessity and urgency of introducing a verification and certification system to promote the introduction and its application of high technology of diagnostic equipment and facility inspection. Also, the introduction to a verification and certification system was reviewed for advanced facility diagnostic equipment through foreign research about similar systems and comparative analysis of similar systems related to the certification of 21 domestic equipment. Result: It showed that, regarding the application of high technology, it is necessary for most managers to introduce high technology such as drones, robots, etc., in the maintenance industry, and when high technology is introduced, it will have a considerable effect in the field. On the other hand, the current technology level in Korea is relatively low, so it turned out to take a certain amount of time for the application of technology. Also, it was found that the management of reliable facility diagnostic equipment will be possible through the introduction of the verification and certification system for facility diagnosis equipment. Meanwhile, the survey is conducted on similar systems about foreign and domestic diagnosis and measuring equipment, etc., but there is no system to verify and certify equipment applied with high technology directly to facility diagnosis maintenance. However, because Japan has a system of verifying the performance of diagnostic equipment and South Korea has 21 similar inspection and diagnostic equipment certification systems among 186 certification systems, it is considered to be possible to design systems which utilize them. Conclusion: According to the managers' opinion, it seems that the introduction of the system supporting the application of 4th industrial technology for the equipment and the use of the equipment with high reliability has sufficient validity. However, because our high technology level is undervalued compared to the urgency, the system for checking high technology facilities and certifying diagnostic equipment should be to be implemented in form of escalation considering technical use and verification level. Apart from the introduction of the verification and certification system, it is necessary for special investment, support and efforts to promote advanced facility diagnostic equipment.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.24 no.3
• /
• pp.23-33
• /
• 2016

The characteristics of ammonia generated from alkaline stabilization facilities was investigated which are for organic sewage sludge from wastewater treatment plants. The highest concentration of ammonia was found in mixing and curing process in alkaline stabilization facility and ammonia mainly showed a range of 87.78 ppm($66.62mg/m^3$) to 1,933 ppm($1,467.01mg/m^3$) by detection tube. This is presumed to occur because nitrogen oxides are converted into ammonia as the sewage sludge is mixed with lime. In some facilities, hydrogen sulfide and methyl mercaptan were detected in relatively high concentrations, but odor materials except ammonia were not detected in most of the facilities. The concentration of ammonia caused by process was generally high in the order of "mixing > curing > output > storage > drying > input." It was found that odor compounds are removed by wet absorption using sulfuric acid and sodium hypochlorite in the 5 alkaline stabilization facilities currently in operation. Each facility was designed to meet the concentration of after-treatment emission in 1 ppm($0.76mg/m^3$), 50 ppm($37.95mg/m^3$) or 100 ppm($75.89mg/m^3$), but no facility satisfied the design standard for their emssion limit. In case of ammonia, some workplaces in alkaline stabilization facilities exceeded the exposure limits established by the Ministry of Labor. It appears that proper ventilation should be provided for the safety of workers in future. No odor compound including ammonia was found by detection tubes in the border of the facilities, but trace amounts of odor compounds are expected to exist, given the current operational status of facilities.

• Science of Emotion and Sensibility
• /
• v.10 no.3
• /
• pp.331-342
• /
• 2007

This study focused on developing MP3 smart clothing products and usability evaluation. MP3 smart clothing which was developed in this study contains e-textile keypad and a kit. The kit consists of MP3 Player, remote controller module and ear phone, and are easy to assemble and dismantle. And usability evaluation about MP3 smart Clothing which was developed in this study contains e-textile keypad and a kit. For making the MP3 Smart clothing, e-textile signal line and keypad was developed and a metal connection ring also was manufactured to adhere closely e-textile signal line to keypad. The last products are two kinds of MP3 smart clothing, jacket style of MP3-YSJ(Yonsei Smart Jacket) and safari style of MP3-YSS(Yonsei Smart Safari). Then usability evaluation conducted two times about MP3 smart clothing developed. Usability evaluation is classified by a module evaluation and an item evaluation. The module evaluation measured external appearance, material, a music controller, an ear phone(or a mini speaker) and connector. The item evaluation measured social acceptance, feeling of wearing, utility, easiness of maintenance and safety. The module evaluation described totally positive results in the first usability evaluation about MP3-YSJ 1.0 and MP3-YSS 1.0. The item evaluation shows a lower score in the social acceptance, especially the easiness of connector maintenance and the social acceptance of music-controller in MP3-YSJ 1.0 and MP3-YSS 1.0. The second usability evaluation conducted with improved products by the first usability test results. Results from second item evaluation indicated needs to improve the easiness of connector & music-controller maintenance and the social acceptance of music-controller in MP3-YSJ 2.0. In MP3-YSS 2.0, the easiness of material management and the social acceptance of music controller & connector needed to improvement. In particular, users felt inconvenience in the social acceptance because of e-textile keypad arrangement. To outweigh this disadvantage, further study is needed about keypad interface of the music controller.

• Journal of Korea Water Resources Association
• /
• v.48 no.12
• /
• pp.1065-1075
• /
• 2015

In the estuary where the structure such as river-mouth weir has been installed, the flow is developed very complicatedly due to river water from upstream, tide of the sea and floodgate operation. Especially, if basin outlets more than one exists in one estuary, the boundary conditions will be significantly more complex form. Saemangeum(SMG) project area in Korea is the most typical example. There are Mankyung river and Dongjin river in upstream. The water of them inflows into SMG project area. In the downstream, river flow was drained from inland to sea over the SMG sea dike through the sluice. The connecting channel was located between Mankyung and Dongjin basins. It functions not only as transportation by ship in ordinary period but also as flood sharing by sending flood flow to each other in flood period. Therefore, in order to secure the safety against flood, it is very important to understand the flood sharing capacity for connecting channel. In this study, the flood control effect was analyzed using numerical simulation. Delft3D was used to numerical simulation and simulated period was set up with neap tide, in which the maximum flood stage occurred due to poor drainage. Actually, three connecting channels were designed in land use plan of the SMG Master Plan, but they were simplified to a single channel for conciseness of analysis in this study. According to the results of numerical analysis, the water level difference between two basins was increased and the maximum flood stage at dike sluice was also upraised depending on decrease of conveyance. And the velocity induced by same water level difference was decreased when the conveyance became smaller. In certain conveyance above, there was almost no flood control effect. Therefore, if the results of this study are considered for design of connecting channel, it will be expected to draw the optimal conveyance for minimizing dredging construction cost while maximizing the flood control effect.

• Applied Biological Chemistry
• /
• v.51 no.1
• /
• pp.70-78
• /
• 2008

Prunus sargentii R. of Rosaceae familiy, has been reported to have radical scavenging activity and anti-inflammatory effect. On these facts, biological activity and safety test were conducted to evaluate biological activities of the extracts of P. sargentii R. as a potential pharmaceutical ingredient. The electron donating ability of its ethanol extracts at a 500 ppm level showed 92%, which was higher than that of hot water extract (59%), the superoxide dismutase (SOD)-like activity of the water extract of P. sargentii R. was about 50%, the ethanol extract of P. sargentii R. was about 40% at 1,000 ppm concentration. Xanthine oxidase inhibition by the water extract of P. sargentii R. was about 40% and that by the ethanol extract was 60% respectively at 500 ppm concentration. From the measurement on lipid oxidation, the $Cu^{2+}$ chelating effect of the ethanol extract was higher than that of hot water extract. The $Fe^{2+}$ chelating effect was also shown to be about 80% at a 500 ppm concentration in both hot water extract and ethanol extract. The tyrosinase inhibition effect related to skin-whitening was 26% by hot water extract and 20% by ethanol extract respectively at a 1,000 ppm. Hyaluronidase inhibition activity related to the anti-inflammation effect was 96% in ethanolic extract at a 500 ppm. Clear zones formed by P. sargentii R. against the human skin-resident micro-flora such as Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli and Propionibacterium acnes indicated that antimicrobial activity of the ethanol extract was higher than that of the hot water extract.