• KIEAE Journal
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• v.11 no.2
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• pp.9-15
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• 2011

Many Korean palaces such as Deoksu Palace and Kyungbok Palace are located in downtown Seoul. Modern high-rise buildings around the palace have been the background scenery of traditional architecture in it. In this case, such landscapes mixed with traditional images and contemporary images can give a negative impression to visitors watching from inside the palace. In this study, we analysed the correlation between landscape image of Deoksu Palace and trees' view blockage of buildings around it with three independent variables. The first variable is completely blocked view of buildings around the palace by the trees. The second variable is half-blocked view of buildings around the palace by the trees. The third variable is the view of buildings around the palace that is not blocked by the trees. The analysis showed that there were some significant correlations between landscape image of Deoksu Palace and trees' view blockage of buildings around it. It also showed that the view blockage ratio by the trees has positive correlation with improvement of landscape image of the palace.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.2 s.121
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• pp.55-63
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• 2007

The purpose of this study is to create a planting design for progressive realization. For this, visual preferences as measured via questionnaire were evaluated by the Scenic Beauty Estimation(SBE) and paired comparison methods. The results can be summarized as follows. Through photo observation, the average visual blockage ratio was 38% and the range of degree of the visual blockage ratio was $30{\sim}50%$. The sketch simulation and filtered pattern received the highest preference score and fumed out to be the most practical pattern out of all the patterns evaluated. Also, in the sketch simulation, the high preference values were observed for a distance of 9 to 12m from the view point to the blockage tree with a D/H ratio of 2. The preference score significantly decreased with the increase of the visual blockage ratio having a turning point at $30{\sim}35%$ of the visual blockage ratio, even though the distance parameters were more important than the visual blockage ratio in the scores. An outstanding view must be handled properly to be preserved or accentuated. Framed, open, enclosed, screened or filtered pattern views should be completely revealed only from their best vantage point, not given away at first glimpse. It this sense, parallax spatial beauty with trees could be improved through the visual aspects of plan arrangements and seems to be an effective design technique for landscape planning and planting design.

• Nuclear Engineering and Technology
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• v.53 no.9
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• pp.2847-2858
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• 2021

When a nuclear reactor with rectangular fuel assemblies runs for a long time, impurities and debris may be taken into coolant channels, which may cause flow blockage, and the blocked fuel assemblies might be destroyed. Therefore, the purpose of this study is to perform a thermal-hydraulic analysis of a rectangular fuel assembly by STAR-CCM+, under the condition of one subchannel with 80% blockage ratio. A rectangular fuel assembly of the International Atomic Energy Agency (IAEA) 10 MW material test reactor (MTR) is chosen. In view of the gasket material taken into the coolant channel is close to the single side of the coolant channel, in the flow blockage accident of the Oak Ridge Research Reactor (ORRR), a new blockage category called single side blockage is attempted. The blockage positions include inlet, middle and outlet, and the blockage is set as a cuboid. It is found by simulations that the blockage redistributes the mass flow rate, and large vortices appear locally. The peak temperature of the cladding is maximum, when the blockage is located at the single side of the coolant channel inlet, and no boiling occurs in all blockage cases. Moreover, as the height of the blockage increases, the damage caused by the blockage increases slightly.

• Journal of the Korean Institute of Rural Architecture
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• v.6 no.2
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• pp.31-42
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• 2004

Although the coastal area of Jeju has already been developed, it has high pressure and demands for development continually increasing due to the increase of tourism and leisure activities. Therefore, the purpose of this study is to present objective guidance for the planning of the buildings on the seaside road with a view which have the largest impact on coastal landscape in order to enhance its visual quality. The results of this study are as follows : 1) It is chief element to make guidance for the use and planning of buildings in the conservation of the coastal landscape. 2) The D/H ratios which immediately influence an angle of elevation are different one another for the whole street. To ensure a sense of openness for the landscape, it is needed to maintain under $27^{\circ}$ angle of elevation, which demands 1~3 D/H ratio. 3) It is important to make 2.4 visual blockage ratio for whole street, but the actual condition is 4.48 ratio on average. To bring down the visual blockage ratio, the W/D ratio needs to be regulated. 4) Various techniques are also needed for lively building styles going with coastal landscape.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.3
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• pp.553-562
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• 2020

S-band, C-band and X-band radars are used for weather observation purposes. Since the Meteorological Administration, the Ministry of Environment, and Republic of Korea Air Force operate radars according to the purpose of observation by departments, the installation site and observation characteristics are different. From a meteorological point of view, blind observational areas in the low level with an elevation of less than 1 km around the mountainous terrain near Jirisan and Taebaeksan. Assuming a small radar installation, we simulated low-level observations. In order to monitor dangerous weather in North Korea, we analyzed the precipitation of North Korea and simulated a large radar network. Finally, a radar network for Korean Peninsula was proposed.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.1
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• pp.76-81
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• 2014

Purpose: Diversity and the lachrymal duct deformities and the passage inside the nasal cavity except for anterior image such as epiphora happens during the test were able to express more precisely during the dacryoscintigraphy. Also, we thought about the necessity of a method to classify the passage into the naso-lachrymal duct from epiphora. Therefore, we are to find the validity of the method to obtain both oblique views except for anterior views. Materials and Methods: The targets of this research are 78 patients with epiphora due to the blockage at the lachrymal duct from January 2013 to August 2013. Average age was $56.96{\pm}13.36$. By using a micropipette, we dropped 1-2 drops of $^{99m}TcO4^-$ of 3.7 MBq (0.1 mCi) with $10{\mu}L$ of each drop into the inferior conjunctival fold, then we performed dynamic check for 20 minutes with 20 frames of each minute. In case of we checked the passage from both eyes to nasal cavity immediately after the dynamic check, we obtained oblique view immediately. If we didn't see the passage in either side of the orbit, we obtained oblique views of the orbit after checking the frontal film in 40 minutes. The instrument we used was Pin-hole Collimator with Gamma Camera(Siemens Orbiter, Hoffman Estates, IL, USA). Results: Among the 78 patients with dacryoscintigraphy, 35 patients were confirmed with passage into the nasal cavity from the anterior view. Among those 35 patients, 15 patients were confirmed with passage into the nasal cavity on both eyes, and it was able to observe better passage patterns through oblique view with a result of 8 on both eyes, 2 on left eye, and 1 on right eye. 20 patients had passage in left eye or right eye, among those patients 10 patients showed clear passage compared to the anterior view. 13 patients had possible passage, and 30 patients had no proof of motion of the tracer. To sum up, 21 patients (60%) among 35 patients showed clear pattern of passage with additional oblique views compared to anterior view. People responded obtaining oblique views though 5 points scale about the utility of passage identification helps make diagnoses the passage, passage delayed, and blockage of naso-lachrymal duct by showing the well-seen portions from anterior view. Also, when classifying passage to naso-lachrymal duct and flow to the skin, oblique views has higher chance of classification in case of epiphora (anterior:$4.14{\pm}0.3$, oblique:$4.55{\pm}0.4$). Conclusion: It is considered that if you obtain oblique views of the bilateral orbits in addition to anterior view during the dacryoscintigraphy, the ability of diagnose for reading will become higher because you will be able to see the areas that you could not observe from the anterior view so that you can see if it emitted after the naso-lachrymal duct and the flow of epiphora on the skin.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2252-2254
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• 2002

The Reactor internal structures which consist of many complex components are subjected to flow-induced vibration due to high temperature and pressure in Reactor coolant system. The above flow-induced vibration causes degradation of structural integrity of the Reactor and may result in loosing mechanical binding component which might impact other equipment and component or cause flow blockage. It is important to analyze reactor noise signal for the early detection of potential problem or failure in order to diagnosis reactor integrity in the point of view of safety and plant economics. Detailed composition of diagnostic system reactor internal structures using neutron noise(RIDS).

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2166-2168
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• 2001

Reactor Noise is defined as the fluctuations of measured instrumentation signals during full-power operation of reactor which have informations on reactor system dynamics such as neutron kinetics. The Reactor internal structures which consist of many complex components are subjected to flow-induced vibration due to high temperature and pressure in reactor coolant system. The above flow-induced vibration causes degradation of structural integrity of the reactor and may result in loosing mechanical binding component which might impact other equipment and component or cause flow blockage. It is important to analyze reactor noise signal for the early detection of potential problem or failure in order to diagnosis reactor integrity in the point of view of safety and plant economics. Detailed design of hardware diagnostic system reactor internal structures using neutron noise(RIDS).

• Journal of computational fluids engineering
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• v.19 no.4
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• pp.61-67
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• 2014

Since the most of the existing non-Newtonian models are not adequate to apply to the lattmce Boltzmann method, it is a challenging task from both the theoretical and the numerical points of view. In this research the hydro-kinetic model was modified and applied to the 3-D moving sphere in the circular channel flow and the characteristics of the shear thinning effect by the HK-model was evaluated and the condition of ${\Gamma}$ in the model was suggested for the stable simulation to generate non-trivial prediction in three dimension strong shear flows. On the wall boundaries of circular channel the curved wall surface treatment with constant velocity condition was applied and the bounceback condition was applied on the sphere wall to simulate the relative motion of the sphere. The condition is adequate at the less blockage than 0.7 but It may need to apply a multi-scale concept of grid refinement at the narrow flow region. to obtain the stable numerical results.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.11
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• pp.1503-1512
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• 2002

From the view of the environmental protection against the use of fossil fuels, a great of efforts have been exerted to find an alternative energy source. Hydrogen may become an alternative However the product species of the hydrogen flame is only $H_2O$, which emits only non-luminous radiation so the radiation from it is much smaller than that for a hydrocarbon flame. In this study, the authors designed and fabricated a laboratory scale test furnace to study thermal characteristics of hydrogen-air diffusion flame. In addition. the effects of addition of reacting as welt as non-reacting solid particles were experimentally investigated. Among the total heat flux to the wall, about 75 % was occupied by radiation while 25% by convection. When the aluminum oxide (Al$_2$O$_3$) particles were added, the radiative heat flux was reduced due to heat blockage effects. On the other hand, the total as well as the radiative heat flux was increased when the carbon particles were seeded, since the overall temperature increased. The effects of swirl and excess air ratio were also examined.