• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.2
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• pp.287-298
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• 1989

A numerical work was performed to study the flow behaviors of the open channel type flow with its geometric boundary conditions being similar to that of the Multi-Stage-Flash evaporator with and without a baffle. For the analysis, two-dimensional steady turbulent flow was assumed and the widely known k-.epsilon. turbulence model was usded. SIMPLE algorithm and the power difference scheme were used for the numerical approach. Numerical results generally agree with the previous experimental results though there are some uncertainties at far downstream and near the free surface due to the three dimensionality of the flow and surface waves. Without a baffle, the flow has basically the shape of the submerged plane wall jet with its upper boundary at downstream being sharply curved toward the free surface. For the flow with a baffle, recirculation flow patterns are observed at the upper inlet portion and at the backside of the baffle. For the case without a baffle, it was also confirmed that the ratio between the liquid level and the gate opening height is the most important parameter to determine the flow behavior.

• Journal of the Korean Society for Nondestructive Testing
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• v.13 no.3
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• pp.7-13
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• 1993

Fracture behavior of pre-cracked compact tension specimens made of AISI 4130 steel was investigated using acoustic emission (AE) and ultrasonic C-scan measurements. While each specimen was loaded up to a certain level, various acoustic emission parameters were recorded together with the crack opening displacement (COD). An elastic-plastic finite element analysis was performed to calculate COD and the damage (plastic) zone size ahead of crack tip. Ultrasonic C-scans, in a pulse-echo, immersion mode, were done for mapping the damage zone size. The agreement between the finite element results and the measured COD was satisfactory. Based on AE results, the test specimens were found to show ductile behavior. The slope of the total ringdown counts vs. COD curve was useful to determine the crack initiation. The preliminary C-scan images showed evidence of changes in the amplitude of ultrasonic signal in the damaged region, and the shape and size of the damage zone matched qualitatively with the finite element results. A further work on the damage zone sizing was also pointed out.

• Journal of the Korean Graphic Arts Communication Society
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• v.20 no.2
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• pp.31-43
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• 2002

Screen printing is a stencil process whereby ink is transferred to the substrate through a stencil supported by a fine fabric mesh. Therefore screen had a tendency to distort and swell, as ink was deposited between the fibers, and were difficult to clean. The tow importance of stencil parameters that affect print quality are stencil thread diameter and the fabric thickness because of their influence on both ink deposit and print definition. Since screen printing inks can be formulated to adhere to almost any surface, and the printing process itself can be handled almost any substrate in a wide variety of shape, screen printing is a very versatile process. The small size pronting is reproduced image used screen printing because the surface of substrates is not suited at screen printing method. In screen printing, the need of high definition printing is gradually increasing according to developing special inks. A conventional haftone, so called AM screening, is simple and easy to implement, but the haftone dot patterns by using this method are not free for the moire fringe. This paper is used densitometry and image analysis to investigate relation with printing according to screen mesh, opening size and resolution of copy in image reproduction used FM screen. We had the good result of dot gain and tone reproduction on the screen printing of high definition using FM screen.

• The Research Journal of the Costume Culture
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• v.18 no.5
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• pp.960-976
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• 2010

Even though Joseon Dynasty strictly identified between military and civil officials, the dress and its ornament have been studied only based on embroidery emblems that are correctly identified between military and civil officials. Thus, this study intends to research the features of the only military officials uniform, Cheollik, different from the civil officials's identifying them with other features shown from the records, unearthed relics, stone statue, Joseon-tongsinsa-haengnyeoldo(Illustration of Joseon Delegation to Japan), etc., and its results are as follows: First, for wearing examples of the military officials, from the facts that they had worn mainly ordinary clothes, etc. on announcement of military service examination. There was no difference between military and civil officials's clothes by Daejeonhusokrok and the other documents, and there was an assertion that the form of the military and civil officials's clothes should be different by the document, Hongjejeonseo, in the latter term of the Joseon Dynasty. It is presumed that length, width and shape of sleeves might have been different. Second, unearthed Cheollik of the military officials are mostly from the 16th~17th centuries and most of them have removable sleeves according to statistics. The skirt had an opening and one or two slits. Various textiles were used. Third, military official statues of high governor wear small caps and helmets. They wear Cheollik with the collars same as the collar of Bangryeong and Jikryeong, which is also called Dopji Cheollik. It would be considered as they wear the Bangryeong on top of the Cheollik. Fourth, militarly officials described on the Joseon-tongsinsa-haengnyeoldo(Illustration of Joseon Delegation to Japan) wear Cheollik, Rip, Donggae, Okro, Hongsadae, Hwando, Deungchae.

• Journal of Conservation Science
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• v.32 no.4
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• pp.449-457
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• 2016

A stoneware bottle was recovered from the Incheon Yeongheungdo Shipwreck in 2013. Primary observations showed that this object had a sealed opening and was covered with a foreign material. After it was cleaned via mechanical and chemical methods, wave patterns were observed on the outer surface of the bottle and a yellowish-brown transparent material was found within. In this paper, the process of conserving the stoneware bottle and the analysis conducted on the unknown material found within is explained. The conservation process included steps such as cleaning, desalination and restoration. After of the missing area located at the rim, the original shape of the bottle was made clear. In addition, the unknown inner material was analyzed using FT-IR and GC-MS. Results showed that the material is similar to golden lacquer. It is speculated that the Yeongheungdo Ship had wrecked during the Unified Silla period while carrying a bottle loaded with golden lacquer.

• The Korean Journal of Physiology
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• v.11 no.1
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• pp.45-50
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• 1977

This study was undertaken to investigate the effect of cingulate cortical ablation upon gastric ulceration, and the pathway through which cingulate cortex exerts the effect. 56 female rats were divided equally into cingulate (cingulate cortical ablation), cingulate-vagal (cingulate cortical ablation and vagotomy), normal control and vagal (vagotomy) groups. Cingulate cortex was ablated through a slit-shaped opening (1 mm in width, 13 mm in length) which was made symmetrically on both sides of, and parallel to, the sagittal suture by removing a bone flap from parietal and frontal bones on each side. Vagus nerves on both sides were transected around the distal end of the esophagus. In the normal control animals, surgical intervention ended with scalp incision. All rats were kept without restraint or food deprivation for 3 weeks after surgery. The stomach of each rat was inflated with 7 ml of physiological saline and then removed under deep anesthesia. The mucosal surface was examined under dissecting microscope for the location, shape and number of ulcers, and then enlarged photograph $(4{\times})$was taken. The incidence of ulcer in each group was counted and the number of ulceration as well as the total area of glandular mucosa were measured on the photograph. Results obtained were as follows: 1. The mean number of ulcer per stomach and the total area of ulcer exprssed as permillage of the total area of glandular mucosa were significantly higher in the cingulate group than the cingulate-vagal, the normal control and the vagal groups. There was no difference among the latter three groups. 2. The incidence of ulcer in the cingulate group was significantly higher than that in the .normal control group and was also higher, though not significantly, than those in the cingulate-vagal and the vagal groups. There was no difference among the normal control, the cingulate-vagal and the vagal groups. It is inferred from the above results that the cingulate cortex exerts an inhibitory influence upon gastric ulceration and that this influence is mediated by controlling the vagal activity.

• The KSFM Journal of Fluid Machinery
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• v.18 no.6
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• pp.45-56
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• 2015

This paper aims to develop a submerged propeller turbine for micro hydropower plant which allows to sustain high values of efficiency in a broad range of hydrological conditions (H=2~6 m, $Q=0.15{\sim}0.39m^3/s$). The two aspects to be considered in this development are mechanical simplicity and high-efficiency operation. Unlike conventional turbines that have spiral casing and gear box, this is directing driving and no spiral casing. A 10 kW class turbine which has the most high potential of the power generation has been developed. The most important element in the design of turbine is the runner blade. The initial blade is designed using inverse design method and then the runner geometry is modified by classical hydraulic method. The design process is carried out in two steps. First, the blade shape is fix and then other components of submerged propeller turbine are designed. Computational fluid dynamics analyses based on the Navier-Stokes equations have been used to obtain overall performance data for the blade and the full turbine, respectively. The results generated by performance parameters(head, guide vane opening angle and rotational speed) variations are theoretically analysed. The evaluation criteria for the blade and the turbine performances are the pressure distribution and flow's behavior on the runner blades and turbine. The results of simulation reveals an efficiency of 91.5% and power generation of 10.5kW at the best efficiency point at the head of 4m and a discharge of $0.3m^3/s$.

• Journal of the Korean housing association
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• v.25 no.4
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• pp.39-46
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• 2014

This research was for the investigation and analysis of the illustration of modular construction application which is different use by each school facility since modular construction related examples are rare in domestic situation, and it has a limitation because of its being basic research material for generating the basic form of modular construction. The research results are as followings. First, in case of school facility from illustration investigation results, module measurement of class modulation is as similar as $3m{\times}10m$, but in resident facility the planning of more flexible plane shape can be possible since modules of 6 cases are free and various, and facade form of various types can be appeared by combination of module unit. Second, as a result of the generated characteristics in compared analysis of representative examples, school facilities were highly indicated for movability and duration reduction areas, and the flexibility, economic efficiency, and environment-friendliness was indicated low relatively. Third, the basic planning types of modular construction can be largely divided into layered type, horizontal (straightway) type, and compound type. The layered type has a short traffic line and facility system and is appropriate for the low-rise form unless separate construction method is used since it is susceptible to load. The horizontal type is advantageous for securing an opening since it has wide extent in light but has a long traffic line and facility system. Finally, the compound type can be possible for planning of various forms but needs the combination of various unit modules and traffic line and facility plan for it can be difficult.

• Korean Journal of Environment and Ecology
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• v.22 no.2
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• pp.128-137
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• 2008

The purpose of this study is to analyze the effect of hiking trails on forest landscape's fragmentation, based on which also to assess the landscape-ecology-based integrity by small drainage area by selecting Bukhansan National Park as a survey target. The results of effect analysis are as follow; size of forest patch decreased; the density of patch and edge increased; patch shape became complicated; the dimensions of core area noticeably decreased and proximity degree between patch increased after trail-building. In addotion, the assessment results of overall landscape ecology-based integrity by small drainage basin showed that the Bukhansan catchment area was highest making 3.7 point, while Gugi catchment area was rated the lowest making 1.6 point. Putting the above results together, it is necessary to prohibit the opening up of unnecessary trails and to make room for ecological restoration of damaged and disturbance area to their original state as nature goes for landscape-ecology-based conservation and management of forests.

• Journal of the Korean GEO-environmental Society
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• v.6 no.2
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• pp.21-30
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• 2005

The purpose of this study was to evaluate the effect of vegetation on the cutting slope applied by vegetation system in the whole land. The engineering characteristics of slopes were investigated using the face mapping and physical tests. From the statistical methods, a relationship between a geologic stratum and degree of covering was independent. Therefore, the afforestation of slope was affected more by condition of vegetation as direction and opening of joints, and a topsoil state than by conventional classification of layer. It was concluded that the adjustable vegetation on the slope considering condition of geometric shape of slope, joint data and spontaneous type could make useful early afforestation.