• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.4
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• pp.1993-1999
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• 2013

Steel composite structures have been studied in various areas such as bridges, high rise buildings, and wind towers. They show excellent structural performance through overcoming of the weaknesses of steel and concrete. Although various methods were already developed to achieve full composite behavior between steel and concrete in flexural members, the number of studies regarding composite columns is quite limited. If slip occurs between concrete and steel under external loads, the performance of the composite column would be reduced significantly. Connection methods ensuring full composite action between steel and concrete must be suggested. This paper investigated about structural behavior of shear studs through a series of experimental tests. Extensive parameters were also performed to understand the effects of the diameter of stud, space of stud and height of concrete. The present study provides fundamental bases for further development of design method of shear studs in composite columns.

• Journal of radiological science and technology
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• v.39 no.3
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• pp.361-368
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• 2016

As the tertiary industry is being developed, many problems are introduced in an industrial area in Korea. This study aims to investigate the residents' health conditions, such as the prevalence of metabolic syndrome and fatty liver diagnosed by ultrasonography, comparing the urban with the industrial areas. The subjects were 378 adults in the urban area and 376 adults in the industrial area. Subject variables accounted for were gender, age, drinking habits, smoking habits, physical activities, waist circumferences and BMI. In blood tests, fasting blood glucose, triglyceride, HDL, blood pressures, total cholesterol, AST, ALT and GGT were examined. Also, the presence and absence of fatty liver, diagnosed using ultrasonography, was investigated. As a result, the prevalence of metabolic syndrome were 43.7% in the urban area and 51.6% in the industrial area, hence it was significantly higher in the industrial area than in the urban area. Fasting blood glucose, triglyceride and waist circumference in the distribution of the individual components were 47.4, 53.7, and 16.1% in the urban area and 54.5, 61.5, and 22.9% in the industrial area respectively, so it was substantially higher in the industrial area than in the urban area. On the other hand, HDL, diastolic blood pressure, and fatty liver were 25.7, 43.4, and 44.7% in the urban area and 21.3, 19.9, and 36.7% in the industrial area respectively and thus it was much higher in the urban area than in the industrial area. In conclusion, this study shows that there were significant differences between the residents' health condition, comparing the urban area to the industrial area. Therefore, the precaution and aggressive management of metabolic syndrome may be necessary, in accordance with the characteristics of the industrial zone.

• Journal of The Korean Society of Grassland and Forage Science
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• v.34 no.2
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• pp.103-107
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• 2014

Tall fescue (Festuca arundinacea Schreb.) is one of cool-season adapted perennial grass species and has been cultivated worldwide as a important forage and lawn grass. In this study, we evaluated the seed production of new tall fescue cultivar, 'Purum', which was cultivated in Korea. Agronomic aspects of tall fescue were determined using seed production and forage nutritive value of straw at the National Institute of Animal Science, RDA from 2012 to 2013. The heading date according to the seeding time displayed 2~3 days differences. The harvested seed yields were the largest (1,711 kg/ha) when seeding date at September $17^{th}$, whereas it decreased when planted ten days earlier or later than at that time. The thousand-grain weight of gathering seeds was 2 g, and the germination rate was 80 to 83% showing no significant differences among the different seeding times. The yield of fresh weight and dry matter were the largest (63,556 kg/ha and 16,926 kg/ha, respectively) when planted at September $17^{th}$. The dry matter yield was gradually decreased with delaying seeding time as 10 days period. However, nutritive values of straw did not showed significant differences.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.5
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• pp.2368-2373
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• 2012

In this research, finite element method was carried out to evaluate the defomation of pipe and surface displacement for backfill of underground ficility. Various conditions for analysis were employer, including two different pipes(PE and concrete pipe), two different excavation depth(60cm and 150cm) and width(1.5D and 2D), a regular sand backfill, and four different flowable backfills. The vertical deformation of 60 cm diameter for PE was measured three times more than that of 30 cm diameter. The measured deformations for regular backfill and four flowable backfills were 0.320mm, and 0.135mm to 0.155mm, respectively. It ratio was around 40%. In case of 30cm diameter of concrete pipe, the measured vertical defomation was around 0.004mm for all the backfill materials. In case of installation depth, the effect of flowable backfill for flexible pipe is better than for rigid pipe. There is little effect on the deformation of concrete pipe with regular sand backfill and flowable backfill.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.5
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• pp.2285-2290
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• 2012

This study is about atherosclerosis which occupies the highest rate in many diseases people have and we have studied about atherosclerosis for abdominal aorta. Atherosclerosis is the phenomenon which blood vessel gets narrower, harder and thicker due to the stenosis of colesterol in blood vessel. If it becomes worse, arteries will be hard and blood can't flow smoothly, and even it can reach to death. In this study, the geometric models of the considered stenotic blood flow are two different types of constriction of cross-sectional area of blood vessel; 20 and 45% of constriction in each elastic wall and rigid wall. We have modeled by using finite element method to observe the changes of velocity and pressure. In case of the diameter of blood vessel decreased 45% in elastic wall model, the values of velocity and pressure were higher than the case of 20% and in case of the diameter of blood vessel decreased 45% in rigid wall model, the values of velocity and pressure were higher than the case of 20%. In cases of elastic wall models of the diameters of blood vessels decreased each of 20% and 45%, recirculation zones appeared. This results show understanding of hemodynamic properties depending on stenosed blood vessels.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.4
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• pp.305-317
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• 2003

Underwater shape and hook depth in tuna longline gear are important factors to decide fishing performance. It also should be considered that management and analysis of hooked rate data from hooked fish species and sizes, and each fishing would be used as a reference data in the future fishing. In this research, after analyzing underwater shape of tuna longline gear by current direction and speed using simulation, experiments were executed in flume tank to verify accuracy of the analysis. Also using the depth of each hook from the simulation, a database system was setup to process the data of bait and hooked fish species. The results were as follows；1. When the attack angle and the shortening rate are fixed, a decrease of the hook depth is proportion to an increase of current speed. 2. When the shortening rate and current speed are fixed, a decrease of hook depth is proportion to an increase of attack angle. 3. When the attack angle and velocity of flow are fixed, a decrease of hook depth is proportion to an increase of shortening rate 4. As a result of comparison between the underwater shape by simulation and that by model gear, the result of the simulation was very close to that of model gear within $$ {\pm}3%$$ 3% error range. 5. In this research, hooked rate database system using hook depth of simulation can analyze the species and size of fish by the parameter; bait. hook depth, so It could be helpful to manage and analyze the hooked data on the field.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.20 no.1
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• pp.37-42
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• 1984

This paper deals with the characterics of the stability of uncontinuous plate structures with cracks. The relation between the J-intergal of the cracks existing in the stress-concentrated regions and local strain are investigated experimentally and theoretically. The BEM(boundary element method)analysis and test results lead to the follow conclusions: 1. A non-dimensional J was computed in a plate stress and strain condition for several kind of loads and crack types. The J design curves are defined as follows: J sub(E)/$\sigma$ sub(y) super(2) a=3.345(e/e sub(y) ) super(2) at e/e sub(y)$\leq$1 J sub(E)/$\sigma$ sub(y) super(2) a=3.345(e/e sub(y) ) at e/e sub(y)$\geq$1 2. Use of this curve provides a good estimation for the uncontinuous plate structures with cracks existing in the stress and strain concentrated region. 3. The stability of the characteristics is mainly depenent upon not the length of cracks but the type of the cracks.

• Korean Journal of Construction Engineering and Management
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• v.14 no.4
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• pp.84-96
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• 2013

Recently, architectural design has been changing from formal design to freeform design due to the digitalization of construction industry. Especially, the formal design has been accepted as a design trend recently and applied many times as a design concept in the architectural design competitions such as turn-key. However, various deflects such as water leak and cracks have been occurred because the traditional construction methods had been applied without any revision or adaptation of the formal construction method for the freeform building construction. Design and construction of freeform building has been developed as an new method in order to solve the problems and minimize the construction duration and cost for the freeform building. Therefore this research deduced the positive implications for developing freefrom envelope by analyzing the domestic and abroad cases and proposed the considerations during design and construction of the freeform envelope as follows. First, the freeform design should consider the constructability for the freeform envelope. Second, manufacturing technology for the two-way curvature of the unit panel should be developed. Third, exposed concrete form method should be developed for the freeform envelope of concrete. Forth, material characteristics, construction method and facility management should be considered in order to manage precipitation and keep water-proof according to the classification of the freeform envelope area.

• Journal of Digital Convergence
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• v.11 no.3
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• pp.273-277
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• 2013

Phishing attacks have been implemented in smarter, more advanced ways with the passage of time. Hackers use intelligent phishing attacks to take over computers and to penetrate internal networks in major organizations. So, in this paper, a model for a prevention of phishing attack spread is conceptual designed in order to protect internal users and sensitive or important information from sophisticated phishing attacks. Internal users simultaneously utilize both external web and organizational mail services. And hackers can take the both side equally as a vector. Thus, packets in each service must be monitored and stored to recognize threatening elements from both sides. The model designed in this paper extends the mail server based security structure used in conventional studies for the protection of Internet mail services accessed by intranet users. This model can build a list of phishing sites as the system checks e-mails compared to that of the method that directly intercepts accesses to phishing sites using a proxy server, so it represents no standby time for request and response processes.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.8
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• pp.507-516
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• 2013

Mobile devices have limited computing power and resources. Since mobile devices are equipped with rich network connectivity, an approach to subscribe cloud services can effectively remedy the problem, which is called Mobile Cloud Computing (MCC). Most works on MCC depend on a method to offload functional components at runtime. However, these works only consider the limited verion of offloading to a pre-defined, designated node. Moveover, there is the limitation of managing services subscribed by applications. To provide a comprehensive and practical solution for MCC, in this paper, we propose a self-stabilizing process and its management-related methods. The proposed process is based on an autonomic computing paradigm and works with diverse quality remedy actions such as migration or replicating services. And, we devise a pratical offloading mechanism which is still in an initial stage of the study. The proposed offloading mechanism is based on our proposed MCC meta-model. By adopting the self-stabilization process for MCC, many of the technical issues are effectively resolved, and mobile cloud environments can maintain consistent levels of quality in autonomous manner.