• The Journal of Korean Academy of Prosthodontics
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• v.48 no.4
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• pp.259-265
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• 2010

Purpose: This study was aimed to evaluate the effect of different sizes of $\beta$-TCP/ HA particles on vertical bone augmentation using titanium mesh in the cranium of rabbits. Materials and methods: Six white rabbits weighing 5kg were used. Four circular grooves of 6mm diameter were made by trephine, and five small holes were drilled in the inner surface of each circular gooves. Different sizes of grafts (small 0.3 - 0.5 mm, medium 0.5 - 1.0, large 1.0 - 2.0 mm) were placed respectively in the experimental groups. Titanium mesh (height 3 mm, width 6 mm) was placed. After 8weeks healing period, the rabbits were euthanized, and the specimens were prepared for histological findings. New bone formation and remaining graft area were measured to calculate the ratio of areas occupying the inner space of titanium mesh. Mann-Whitney U-test and Wilcoxon signed rank-test were used for statistical analysis ($\alpha$ = .05). Results: The experimental groups with $\beta$-TCP/HA graft showed a significantly higher new bone formation (P = .003). Comparing different sizes of $\beta$-TCP/HA, there was no statistical difference in terms of new bone formation. The vertical bone formation (i.e. new bone and graft area) was significantly greater in $\beta$-TCP/HA groups (P = .001). In comparison between different sizes of $\beta$-TCP/HA, medium size group had significantly greater area than large particle size group (P = .039). Conclusion: The use of $\beta$-TCP/HA with titanium mesh showed a higher vertical bone formation, particularly the medium sized $\beta$-TCP/HA particles (0.5 - 1.0 mm) produced better results in vertical bone augmentation.

• Journal of Energy Engineering
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• v.12 no.3
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• pp.223-230
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• 2003

A study was performed to measure and analyze the gas-side fouling of heat exchanger to cool the exhaust gas from sludge incinerator at ironworks. The incinerator gas passes through inside of the vertical tubes of heat exchanger to preheat the combustion air. This kind of fouling occurs at the entrance region of the heat exchanger and thus the perforated fouling plate was designed to measure the gas-side fouling and to analyze the particulate deposit. As a result of analysis, the particulate deposition rate was influenced by temperature, particulate composition and size and also the deposition patterns were different according to the location of perforated fouling plate. The computational analysis was performed to obtain the deposition rates at the perforated fouling plate and the calculation showed that the deposition rate was varied with the hole size and particulate size. It was proved that the fouling at the entrance region of heat exchanger could be measured by the perforated fouling plate designed in this study.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.1664-1670
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• 2015

As journal bearing has a sliding motion between the shaft and bearing with lubricating oil, it produces a hydrodynamic lubrication condition. Journal bearing can receive a large force because it takes a distributed load at the large friction face. As the oil groove or oil hole is made in the journal bearing surface for the journal bearing smoothly working under a hydrodynamic lubrication condition, sufficient lubricating oil is supplied through the clearance of journal bearing. The performance of the journal bearing is changed according to the shapes, sizes and positions of an oil groove. In this paper, the flow rate according to the oil groove shapes (triangle, semicircle and rectangle) among the various oil supply conditions was measured. The shape that discharges the highest flow rate was observed and the groove shape of optimal performance for the journal bearing was determined. The results showed that the flow rate increases with decreasing operating temperature, the influence of temperature on the flow rate decreased with increasing rotational speed, and flow rate in the triangular groove shape was greater than in other shapes.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.12
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• pp.36-44
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• 2012

We had introduced the backgrounds, history and physical meanings of Jong Nang in "Jeju Jong Nang Channel Code I". In this paper, we introduce practical the root of digital human binary coded Jong Nang communications as the wooden gate in Korea Jeju Island custom. We investigate Jong Nang gatemodels as an approximation of the AWGN model. The objective is to find a deterministic model, which is accessible to capacity analysis. Furthermore, this analysis should provide insights on the capacity of the AWGN model. Motivated by backhaul cooperation in cellular networks where cooperation is among base stations, we term the interference channel with conferencing transmitters. Jong Nang communicationsis normal 3 rafters placed on two vertical stones with three holes to convey the family's whereabouts that is deterministic signal, nowadays it is applied to backhaul in mobile base station and traffic signal.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.1
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• pp.163-172
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• 1990

The filter criteria of geotextiles to prevent excessive loss of fine particles in cohesion-less soils are largely depend on the flow conditions of water in soil/geotextile systems. In the soil/geotextile system under uni-directional flow conditions, it is adequate to retain only the coarse soil fraction because a 'self-induced' soil filter layer may form in cohesionless soil adjacent to the geotextile. In alternating flow conditions, however, a complete soil filter layer within the soil will not form and thus the geotextile pores must be small enough to retain finer particles of the soil to be protected. Based on these concepts, theoretical filtration criteria of geotextiles are developed considering the flow conditions of water. To test the validity of these criteria, laboratory testing was carried out. This indicated that large losses of fine particles would result, especially at high hydraulic gradients, short periods and low vertical loads. The revised filtration criteria are proposed evaluating effect of various design factors.

• Korean Journal of Plant Tissue Culture
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• v.22 no.3
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• pp.127-130
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• 1995

Japanese pepper (Zanthoxylum piperitum Dc.) tree of selected genotype was propagated by a two-step method. Among the media tested, BTM promoted shoot height growth and DKW revealed as superior to micro-canopy increment Multiple shoot formation was greatest when the single shoot were subcultured on medium containing 0.89 $\mu$M BA alone. The numbers of survival shoots could be markedly increased by acclimatization of the multiplied shoots itself in plastic Petridish (punctured with pin on the top) for two weeks and subsequently transplanting each shoot onto peat plug system. After transplanting the micropropagules onto pots, prickliness characteristics seem to be transmitted to all plane produced from selected genotype.

• Korean Journal of Ichthyology
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• v.10 no.2
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• pp.231-240
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• 1998

The characteristics of cranium, vertebral column and fin supports of Acanthorhodeus gracilis were examined. The fish did not have a fontanell in cranium nor process of supraethmoid. It had double orbitosphenoids and a basioccipital process developed from anterior portion of basioccipital. It had a high and triangular dorsal process on supraoccipital. In the urohyal, hypohyal attachment was bifurcated and horizontal and vertical plate were in an elongated rhombus shape with posterior edge pointed. It had teeth of 1-rowed, 5/5 and 4 free teeth. The fish did not have a coracoid foramen on shoulder girdle. It does not have a uroneural on ural centrum. It had a long and slender posterior process of pelvic bone. It had a large and flat supraneural. The fish had 14 or 15 interneural spines, of which the 1st, 2nd, 3rd and 4th had single basiosts and the rest had double basiosts. It had 11 or 12 interhemal spines, of which the 1st, 2nd, 3rd and 4th had single basiosts and the rest had double basiosts.

• Journal of the Korean association of regional geographers
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• v.11 no.6
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• pp.517-529
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• 2005

Mt. Apsan is well known to be one of the most popular tourist sites around Daegu. Annually, more than 16 million persons visit Mt. Apsan. Although, in the mountain there are varieties of geomorphic and geological resources, there has been less concern to utilize the resources for geo-tourism. For example, there are about 10 valleys within Mt. Apsan and various landforms are scattered around the valleys. In this context, this study, based on field surveys centering around Gosangol valley, Anjiranggol valley and Dalbigol valley, focuses on exploring ways towards developing Mt. Apsan as an example geo-tourist site. The main findings are as follows: 1) The main landforms of Mt. Apsan include river cliff, cavern, free face, mud crack, ripple mark, fold, sheeting joint, talus, alluvial fan, pot hole, fault line, gnamma, columnar joint and metamorphic rock. 2) The guide notes on the landforms are developed. 3) In order to raise a learning effect of visitors on geomorphic resources, 9 nature trails are designed according to valleys and the length of visitor's stay.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.2
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• pp.119-129
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• 2015

Benthic marine algal flora and community structure at Chuksan on the mid-east coast of Korea were investigated seasonally from July 2007 to May 2009. Ninety-eight seaweed species were identified, including 13 green, 23 brown and 62 red algal species. The number of species found ranged between 33 and 63 among seasons. Two green (Ulva australis and Codium arabicum), three brown (Dictyota dichotoma, Sargassum fusiforme and Sargassum yezoense), and eleven red algae (Corallina pilulifera, Lithophyllum okamurae, Pachymeniopsis elliptica, Grateloupia filicina, G. cornea, Hildenbrandia rubra, Chondrus ocellatus, Acrosorium polyneurum, Chondria crassicaulis, Polysiphonia morrowii and Symphyocladia latiuscula) were observed throughout the survey period. Average marine algal biomass was $629.68g\;dry\;wt\;m^{-2}$ and it ranged seasonally from 119.30 to $1,660.96g\;dry\;wt\;m^{-2}$. The vertical distribution of marine algae was characterized by Corallina pilulifera and Sargassum spp. in the intertidal zone; Sargassum spp. at 1 m depth; Sargassum spp. and melobesioidean algae at 5 m depth; and melobesioidean algae at 10 m depth.

• Progress in Medical Physics
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• v.9 no.2
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• pp.89-94
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• 1998

To make practical application of the MR image for stereotactic radiosurgery, the target point-achieved by acquisition of MR image in stereotactic radiosurgery planning system must agree with the actual isocenter of irradiation in real treatment. And the amount of distortion of the MR image must be known to make a correction for the agreement. A radish containing abundant water content was chosen as a homogeneous phantom for the purpose of verification of the agreement in this experiment. A dosimetric film was firmly attached to the small specially fabricated acryl plate and needle puncture was made through the film just into the acryl plate and a drop of oil was dropped into the hole of the film. The acryl plate with film was inserted into the radish and the dorp of oil represented the target point in MR image. After the image acquisition by stereotatic radiosurgery planning system, we achieved stereotactic coordinate of the target point represented by the oil drop. And we proceeded to actual irradiation to the target point according to the procedure of stereotactic radiosurgery. After the irradiation, the film in the radish was developed and processed and the degree of coincidence between the center of the radiation distribution and the target point represented by the hole in the film was measured. The discrepancy between two points was under 0.5 mm. so we could confirm good coincidence in homogeneous phantom such as radish. On the other hand, authors tried to use our home-made device for estimation of distortion of MR image.