• Journal of Computing Science and Engineering
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• 제4권3호
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• pp.207-224
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• 2010

This paper presents a compression scheme for mesh geometry, which is suitable for mobile graphics. The main focus is to enable real-time decoding of compressed vertex positions while providing reasonable compression ratios. Our scheme is based on local quantization of vertex positions with mesh partitioning. To prevent visual seams along the partitioning boundaries, we constrain the locally quantized cells of all mesh partitions to have the same size and aligned local axes. We propose a mesh partitioning algorithm to minimize the size of locally quantized cells, which relates to the distortion of a restored mesh. Vertex coordinates are stored in main memory and transmitted to graphics hardware for rendering in the quantized form, saving memory space and system bus bandwidth. Decoding operation is combined with model geometry transformation, and the only overhead to restore vertex positions is one matrix multiplication for each mesh partition. In our experiments, a 32-bit floating point vertex coordinate is quantized into an 8-bit integer, which is the smallest data size supported in a mobile graphics library. With this setting, the distortions of the restored meshes are comparable to 11-bit global quantization of vertex coordinates. We also apply the proposed approach to compression of vertex attributes, such as vertex normals and texture coordinates, and show that gains similar to vertex geometry can be obtained through local quantization with mesh partitioning.

• 수산해양기술연구
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• 제41권1호
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• pp.27-34
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• 2005

붕장어에 대한 스프링형 그물통발의 망목선택성 및 적정망목을 추정하기 위한 시험조업은 경남 거제시 능포 인근해역에서 2002년 9월25일${\sim}$9월27일에 실시되었다. 시험어구는 현용어구인 15mm, 20mm 및 시험을 위해 제작한 25mm, 30mm 그리고 수산자원보호령에서 규정하고 있는 35mm와 대조어구로써 통수공 6.7mm의 플라스틱 통발을 각각 50개씩 제작하여 사용하였다. 망목선택성은 Kitahara(1968)와 Fujimori(1996)의 방법을 사용하여 분석하였고, 적정망목은 어체 동주와 체장과의 관계 그리고 망목선택성 Master Curve를 사용하여 추정하였다. 그 결과를 요약하면 다음과 같다. 1. 시험조업 결과 총어획미수는 835미로, 붕장어 537미(64.4%), 게류 225미(26.9%), 기타 73미(8.7%)였다. 2. 망목선택성 곡선의 Master Curve에서 최대 전장/망목(max. 1/m)의 값은 23.9로 추정되었다. 3. 붕장어 스프링 통발의 적정망목은 34.0mm로 추정되었다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.202-207
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• 2004

An elastic-plastic finite element analysis of fatigue crack closure is performed for plane strain conditions. The stabilization behavior of crack opening level and the effect of mesh size on the crack opening stress are investigated. In order to obtain a stabilized crack opening level for plane strain conditions, the crack must be advanced through approximately four times the initial monotonic plastic zone. The crack opening load tends to increase with the decrease of mesh size. The mesh size nearly equal to the theoretical plane strain cyclic plastic zone size may provide reasonable numerical results comparable with experimental crack opening data. The crack opening behavior is influenced by the crack growth increment and discontinuous opening behavior is observed. A procedure to predict the most appropriate mesh size for different stress ratio is suggested. Crack opening loads predicted by the FE analysis based on the procedure suggested resulted in good agreement with experimental ones within the error of 5 %. Effect of the distance behind the crack tip on the crack opening load determined by the ASTM compliance offset method based on the load-displacement relation and by the rotational offset method based on the load-differential displacement relation is investigated. Optimal gage location and method to determine the crack opening load is suggested.

• 수산해양기술연구
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• 제30권3호
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• pp.172-181
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• 1994

The mesh selectivity of diamond and suare mesh cod-ends at the Southern Korean Sea and the East China Sea were compared for Pampus argenteus, Trachurus japonicus, Trichiurus lepturus. Selection trials were carried out using diamond and square mesh cod-end by trouser type cod-end with cover net. of which the mesh cod-end has four types : A(51.2mm), B(70.2mm), C(77.6mm), D(88.0mm). Selection curves and selection parameters were calculated using a logistic model. The results obained are summarized as follows : 1. Harvest fish : In B. C and D type selection range and fifty percent selection length of the square mesh were about 21mm, 11mm : 12mm, 18mm and 34mm, 5mm higher than those of the diamond mesh, respectively. Selection factor of master curve for the diamond mesh was 1.54 and for the square mesh was 1.68. The optimum mesh size for the diamond mesh was 97.4mm and for the square mesh was 89.3mm, the difference was 8.1mm. 2. Horse mackerel : In A type, selection range was nearly the same for the diamond and the square mesh, but fifty percent selection length of the square mesh was 43mm higher than the diamond mesh. In B. C and D type, selection range and fifty percent selection length of the square mesh were about 6mm, 3mm : 24mm, 21mm and 11mm, 42mm higher than those of the diamond mesh, respectively. Selection factor of master curve for the diamond mesh was 2.37, for the square mesh was 2.77. The optimum mesh size for the diamond mesh was 78.1mm and for the square mesh was 66.8mm, the difference was 11.3mm. 3. Hair tail : In A, B and C type, selection range of the square mesh was about 34mm, 8mm, 60mm higher than those of the diamond mesh. Fifty percent selection length for the diamond mesh was about 5mm, 7mm, 8mm higher than that of the square mesh. Selection factor of master curve for the diamond mesh was 3.11, for the square mesh was 3.48. The optimum mesh size for the diamond mesh was 64.3mm and for the square mesh was 57.5mm, the difference was 6.8mm.

• 수산해양기술연구
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• 제46권3호
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• pp.195-203
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• 2010

Recently, Fishermen have required to expand the circumference of trap entrance for conger eel because it was difficult to take the catch out as well as to put the baits into. A series of fishing experiments was carried out in coastal areas of Tongyoung, Korea in 2008 and 2009 using the traps to describe the effect of the entrance size on the catch. The experimental traps (five types) were used in filed experiments with four types circumference size traps (140, 180, 220 and 260mm) with mesh size 22mm and another type was used the same one usually using in filed with mesh size 35mm (750mm circumference). The experiment results were, the conger eels of total length 35mm more or so were caught 85, 93, 142 and 176 individual by the experiment traps with mesh size 22mm as increase circumference size from 140mm to 260mm, respectively. And the small conger eels of the total length below 35mm to be prohibited to catch by law were caught 145, 160, 288 and 304 individual according to increase the circumference size of trap, respectively. In addition, in case of the trap with mesh size 22mm, bycatches were 230 - 260 individuals and much more than bycatches of the trap with mesh size 35mm. In conclusion, when we expand the circumference size of trap according to fishermen's requirement, we should review not only economic of fishery but also increasement the bycatch of non-target fishes and small size fishes.

• 한국세라믹학회지
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• 제13권1호
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• pp.35-44
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• 1976

The effect of quartz which exists in clays, especially in kaolin used for the production of chamotte sagger, on the strength of refractory was examined. In this study, a mixture of chamotte 50%, kaolin 25%, plastic clay 25% in ternary component system was selected as a batch composition. To this mixture 1%, 3% and 5% of feldspar and sericite were added respectively. The plastic clay used here was separated under 170 mesh by dry process. Feldspar and sericite were separated under 325 mesh by dry process. Feldspar and sericite were separated under 325 mesh by dry process. In order to change the particle size and the content of quartz, the kaolin was separated under 60, 115, 170 and 325 mesh by wet process, substituted quartz for coarse parts of it. Chamotte was classified into three grades, coarse (5-10mesh): medium (10-20mesh): fine(20-115mesh) and the ratio was 1:1:1. Samples were formed in 0.8xIx10cm size with 12.5% water at 160kg/$\textrm{cm}^2$ pressure, and fired at 130$0^{\circ}C$ for 1 hr. The fired samples were ivnestigated by means of x-ray diffraction analysis and microscopic observation, and the physical properties of them were also examined, such as firing shrinkage, apparent specific gravity and bulk specific gravity, apparent porosity, water absorption and modulus of rupture. The obtained results are as follows: 1. When screened kaolin with low content of quartz was added to fixed chamotte-plastic clay system, the sample lowered modulus of rupture and increased apparent porosity as the size of kaolin became finer. 2. When kaolin under 325 mesh with 7.2-15.81% quartz between 60-325 mesh was added to fixed chamotte-plastic clay system, the sample had higher apparent porosity and lower modulus of ruputure as the size and the amount of quartz became larger. 3. The addition of feldspar and sericite to chamotte-plastic clay system improved apparent porosity and modulus of rupture. The effect of feldspar was better when quartz content was low, although that of sericite was better than quartz content was high.

• 수산해양기술연구
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• 제51권3호
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• pp.396-404
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• 2015

Morotoge shrimp Pandalopsis japonica is caught by pot and others in the eastern coastal waters of Korea. Comparative fishing experiments were carried out in the eastern coast of Korea, using the dome-shaped pots with different five mesh sizes (17.1, 24.8, 35.3, 39.8, and 48.3 mm) in order to estimate the mesh selectivity of the pot for the morotoge shrimp, Pandalopsis japonica. The SELECT (Share Each Length's Catch Total) analysis method was applied to the catch data. The master selection curve of the pot for the shrimp was estimated to be s(R) = exp(15.770R-10.573)/[1+exp(15.770R-10.753)], where R is the ratio of carapace length to mesh size. From the selection curves, the carapace lengths of 50% retention were 11.6, 17.0, 23.9, and 34.1 mm for 17, 25, 35, and 50 mm mesh-size pot, respectively. It means that the pots of larger mesh size allow more shrimp of small size to escape.

• 한국토양동물학회지
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• 제6권1_2호
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• pp.25-31
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• 2001

주변환경의 오염에 의한 스트레스를 받는 정도가 다른 남산과 광릉의 잣나무림에서 낙엽주머니 (mesh size :남산 1.7mm, 광릉 0.4mm, 1 7mm)방법을 이용하여 낙엽의 분해과정에 관련된 날개응애 군집에 대한 분석을 실시하였다. 각 조사구에서 2년에 걸쳐 총 11회 수거한 낙엽주머니에서 조사된 날개응애 종 수는 30종을 초과하지 않았고, 남산과 광릉의 mesh size 1.7mm에서 조사된 종 수는 광릉이 남산에 비해 유의성있게 높았다(paired t-test, p<0.05), mesh size가 다른 광릉 지역의 낙엽주머니간에는 종수의 차이가 없어 남산,광릉 두지역간의 종수 차이만이 인정되었다. 낙엽주머니내 날개응애 체장 분포 및 체장별 밀도 패턴은 세 조사구에서 중형종(0.3-0.7mm미만)이 다수 출현했고, 밀도가 높은 종은 광릉에서는 체장이 0.2-0.5 mm 사이의 종들이, 남산에서는 이들 조사구들보다 조금 더 큰 종들에서 높은 밀도를 보였다. S renson 지수 및 Cluster analysis를 이용한 조사구 날개응애 군집의 정성적, 정량적 분석은 두 지역의 날개응애 군집이 종 구성에 있어 다른 그룹이라는 것을 제시했다. 낙엽주머니내 날개응애 종들의 출현은 20종 미만의 종들이 5월에서 9월 사이에 출현하였는데, 1년차와 2년차간에 출현 패턴에는 다소 변화가 있었다. 낙엽주머니내 날개응애 유입은 1년차에는 5월부터 다수의 새로운 종들이 이입되었지만, 2년차에는 새로운 종의 유입은 미미한 반면 1년차에 이입했던 종들의 재차 유입이 일어났고, 유입시기도 빨라졌다. 낙엽주머니내 날개응애군집의 종 다양도 분석에는 종 풍부도지수, Shannon 지수, 균등도 지수가 사용되었고, 이들 세 가지 다양도 지수의 값이 모두 광릉이 높고 남산이 낮은(mesh size 1.7mm>광릉 mesh size 0.4 mm>남산 mesh size 1.7 mm) 일관된 경향을 나타냈다. 이는 날개응애 군집의 종 다양성은 광릉지역이 남산지역에 비해 더 높다는 결론을 도출할 수 있는 것이었다. 낙엽주머니내 출현종의 우점종과 출현빈도 분석결과, 각 조사구의 우점종들은 전체 밀도의 70%이상을 차지하고 있어 비중이 매우 높은 것들로 나타났고, 최고 우점종은 mesh size 1.7mm의 남산과 광릉 조사구에서 Tricho-galumna nipponica로 동일했고, 광릉 mesh size 0.4 mm에서는 이 종보다 크기가 작은 Ramusella sengbuschi가 최고 우점종이었다. 그리고 낙엽주머니내에 밀도와 출현빈도가 높아 낙엽분해에 직,간접적으로 크게 관여하는 날개응애 종들로는 Tricogalumna nipponica, Epidamaeus coreanus, Scheloribates latipes, Ceratozetes japonicus, Ramusella sengbuschi, Eohypochthonius crassisetiger, Cultroribula lata 등을 선발할 수 있었다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2007년도 추계 학술대회논문집
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• pp.120-125
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• 2007

In this paper a new cell sizing method is proposed. The new method calculates cell size at a point using given size control elements directly without the aid of background grid as other cell sizing algorithms do. The calculation method and related definitions are described in detail, and typical cell sizing results are given.

• 자원환경지질
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• 제19권spc호
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• pp.227-237
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• 1986

The Duk-Eum mine located in Kongsan-myeon, Naju-gun, Cheolanamdo is producing silver ore mainly, with rare gold association. The grade-up and recovery of the concentrates have been concerned to the main problem. And then, this study aimed at applying the basic data for ore processing. In the first half of the study, the attempts were made to identify the ore minerals, this followed by determination of the mineral texture, paragenesis, grain size, and size distribution by employing the microscopical method and the etching test. The results of the study are as follows: 1. The ore deposit is composed of the hydrothermal fissure linked veins, and filling cavities are mostly tensile fractures or joints, in rhyolitic rocks as a wall rock. 2. The principle ore minerals are native silver, acanthite, canfieldite, pyrargyrite, galena, tetrahedrite, sphalerite, pyrrhotite, chalcopyrite, chalcocite, covellite, zincite, and the gangue minerals are quartz and calcite. 3. The grain size of each ore minerals before grinding are; max. $2\frac{1}{2}$ mesh, medium 48-100 mesh(main size, contained over 80%), min. 3200mesh. And the grain size of each ore minerals after grinding is; max. 42mesh, medium 65-250mesh(main size, contained over 80%), min. 3200mesh. 4. The properties of the mineral texture effected on the ore dressing are follows; a) Inclusion texture; the fine grains of chalcopyrite is included in most acanthite, and rarely, that of galena included in acanthite. b) Exsolution texture; pyrargyrite is exsolved in acanthite. c) Replacement texture; native silver replaced pyrargyrite, and acanthite replaced galena. d) Interlocking paragenetic texture; the interlocking paragenetic minerals are pyrite, chalcopyrite, chalcocite, canfieldite. e) Fissure filling texture; chalcopyrite was filled along the cracks in acanthite. Among of the above texture, it is impossible to liberate the grains of a), and more difficult to liberate those of b) and c), while easy to liberate those of d) and e).