• Journal of Forest and Environmental Science
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• 제14권1호
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• pp.1-13
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• 1998

주요 침 활엽수재에 대하여 methyl methacrylate를 이용하여 만든 목재-polymer복합체에 대하여 polymer의 분포와 존재상태등을 목재의 조직학적인 면에서 조사하였으며 그것을 요약하면 다음과 같다. 1. polymer의 침투성은 수종에 따라 다르며 수종고유의 특성에 따라 다르다. 낙엽송은 침투성이 대단히 나쁘며 활엽수재에 있어서는 환공재가 산공재보다 침투성이 양호 하였다. 2. 횡단면에서 침투성이 가장 양호하며 방사단면과 접선단면에서의 주입은 저하되고 양자의 차이는 거의 없었다. 3. 동일 수종에서는 변재가 섬재보다 침투성이 양호 하였다. 수종에 따라 변심재간에 침투성이 다른 것은 심재화에 의한 tyloses의 형성 또는 도관중의 침착물에 의한 것으로 생각되고 있다. 4. 환공성 수종에서는 조재부가 만재부보다 polymer의 침투성이 양호 하였으며 산공재에서는 반대로 만재부가 조재부보다 침투성이 양호하였다. 5. 도관의 크기와 침투성과의 사이에는 명확한 상관이 없는 것으로 생각된다. 도관의 직경이외에도 도관의 비율, tyloses의 발달, 내용물의 충진 혹은 천공판등이 관계하는 것으로 생각되고 있다. 6. 침엽수재 방사조직에 있어서는 방사유세포보다 방사가도관의 침투성이 양호하였으며 활엽수재의 방사조직은 구성비율이 높음에도 불구하고 단량체의 방사방향에 미치는 영향은 침엽수재보다 적었다. 7. 비중과 연륜폭은 모두 polymer의 침투성과 거의 관계가 없었다.

• 한국패류학회지
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• 제19권2호
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• pp.125-132
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• 2003

1999년 1월부터 12월까지 매월 충남 보령연안에 서식하는 살조개 총 2,591 개체를 채집하여 연령과 성장에 관하여 조사하였다. 살조개의 패각에 나타나는 윤문은 연 1회 형성되었으며, 윤문형성 시기는 2-3월 중인 것으로 조사되었다. 각고(SH)에 대한 각장 (SL), 각폭 (SW) 및 총중량 (TW) 사이의 상대성장 관계는 각각 SL = 1.1067 SH + 1.778, SW = 0.6758 SH - 0.9824, TW = 0.0007 SH$^{2.8919}$이었고, 연령 (t) 에 대한 각고와 총중량으로부터 구한 von Bertalanffy 성장식은 SH$_t$ = 81.546(1-e$^{-0.176(t+0.381)}$), $_t$ = 81.546(1-e$^{-0.176(t+0.381)}$)이었다.

• Journal of the Korean Wood Science and Technology
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• 제15권3호
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• pp.1-13
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• 1987

This study was carried out to investigate the variations of dimension and exterior shape of vessel elements, morphology of spiral thickening and ray-vessel pit in korean diffuse-porous woods (56 species, 18 families), The tangential pore diameter and vessel element length was increased, whereas the pore number per unit area($1mm^2$) was decreased from pith outwards. The tangential pore diameter was decreased but the length of vessel element was not changed from earlywood to latewood within an annual ring. However, the dimensional variations of vessel element was not able to be recognized among relative positions in peripheral variation. The exterior shape of vessel element could be classified into four types; Type 1 is without tail, Type 2 with ligulate tail, Type 3 with broad taper tail and Type 4 with the very short length between perforations. The distribution frequency of Type 2 and 3 was relatively high in comparision with the others. According to the prominence, distribution position and branched shape, the spiral thickenings could be divided into five types. The spiral thickenings occurred 52% in the species observed. Thus it was doubtful to consider the simple presence of spiral thickening as diagnostic index in diffuse-porous woods. The morphology of ray-vessel pit could be grouped as reticulate, scalariform, oval, linear and coalescent type. Most of species examined showed oval and linear type.

• 한국수산과학회지
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• 제48권5호
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• pp.760-767
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• 2015

First annulus formation and age determination of otoliths were examined for chub mackerel Scomber japonicus collected in Korean waters over the one year from January to December in 2009. Translucent zone was regarded as an annual mark. Age interpretation criteria was based on the data of the number of translucent zone, capture date, and edge type of the otolith, assuming the nominal birthday to be 1 January. Monthly changes in mean marginal index indicated that translucent zone was formed once a year, mainly in June. The otolith of 0-ring group was detected comparing the progression by month of the smaller fish length, appearing to be a single first opaque zone. The average distance from the core to the first translucent zone was ~1.77 mm, provided as supplementary information to increase ageing accuracy. The ageing criteria for chub mackerel was made to determine correct year-class with the purpose of effective stock assessment. This method using nominal birthdate and edge type analysis could estimate age of fish closer to the true age than purely counting the number of translucent zone on a whole otolith.

• 한국패류학회지
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• 제24권3호
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• pp.189-197
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• 2008

In order to develop the sustainable ecological management, short-necked clams, Ruditapes philippinarum, were collected from Yoengi coast in Tongyoeng, Korea. The growth of the clam was estimated as: $L_f=68.08{\cdot}(1-e^{-0.145(t+0.324)})$ from ring radius composition of shell. Instantaneous co-efficiency of total mortality and natural mortality were calculated as: 0.991/year and 0.494/year, respectively. The age of the clams from the first capture was estimated to be 3.28. The total biomass was estimated to be 212 MT in the fisheries area (6.4 ha). Applied by these parameters, the annual recruit biomass and the current yield per recruit were calculated to be 649.5 individual/$m^2$ and $0.7\;g/m^2$, respectively. The current fishing intensity was much lower for maximum sustainable yield and acceptable biological catch. Although higher yield per recruit could be achieved by increasing fishing intensity, it is favorable to retain the current fishing intensity because of the unique fishing attitude on Yeongi coast in Tongyoeng, Korea.

• 수산해양기술연구
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• 제49권3호
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• pp.261-269
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• 2013

The age and growth of the Pacific cod, Gadus macrocephalus were investigated using left sagittal otoliths of 682 individuals collected in the West Sea of Korea from January to December 2007. The seasonal changes in the ratio of an opaque zone to interval between annular rings revealed that the narrow translucent parts of the otolith were annual growth rings formed between February and March once a year. The spawning period was December to January and therefore the duration from fertilization to the complete formation of the opaque zone became thirteen months. From the parameters calculated using the average length when the year ring was formed, the estimated von Bertalanffy growth equations were $L_t=100.0(1-e^{-0.1640(t+0.5247)})$ for females and $L_t=64.6(1-e^{-0.3335 (t+0.3342)})$ for males when is total length in age t.

• The Korean Journal of Ecology
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• 제6권3호
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• pp.198-207
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• 1983

The dry-matter production, the litter decomposition and the nutrient cycle were studied on Quercus serrata and Carpinus laxiflora forests at Piagol in Mt. Jiri. With the growth curves of the annual ring, the time schedules for the maximum productivities and maximum yields were measured. In Q.serrata forest, the maximum productivity was 11.36 tons $ha^-1 yr^-1$ at the 49th year and the maximum yield was 115.78 tons $ ha^-1$ at the 73th year, and in C. laxiflora 7.24 tons $ha^-1 yr^-1$at the 35th year and 82.5 tons $$ha^-1 $$at the 53th year, respectively. The maximum productivities and the maximum yields of the leaves, stems and roots of the trees were calculated. The contents of nitrogen, phosphorus, potassium and organic carbon were measured.. While inorganic materials were the most abundant in the leaves, organic materials in stems. The maximumproductivities and the maximum yields of the constituents of the trees were calculated, assuming that the constituents of the trees increase allometrically. The decomposition rates were as follows: k = 0.301 for Q.serrata forest, and k = 0.364 for C. laxiflora forest. The litter of the former was decayed more slowly than that of the latter. The halftimes for decomposition were 3.2 and 1.9 years, respectively.

• Journal of the Korean Wood Science and Technology
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• 제38권6호
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• pp.463-469
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• 2010

속성수의 이용가능성을 파악하기 위하여 일본산 속성수 중의 하나인 찬친모도키(Choerospondias)의 물리적 성질, 역학적 성질 그리고 흡음특성을 조사하여 주거재료로서의 적용가능성을 검토하였다. 찬친모도키재는 평균 연륜폭이 약 8 mm 정도로 생장이 빨랐으며 기건비중은 약 0.55이었다. 찬친모도키재는 다른 건축자재에 비하여 흡음성능이 열등하지 않았고 비교적 우수한 강도적 성질을 나타내어 구조재나 마감재 등에의 이용이 가능할 것으로 사료되었다.

• 한국가구학회지
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• 제12권1호
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• pp.47-55
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• 2001

Violin bridge blank cut from maple wood with good quality has typical pattern of the radial direction in the side edge with minimal dispersion. This experimental study was designed and carried out to examine the effect of the physical and macroscopical characteristics on the compressive creep of violin bridge blank which had been imported from European manufacturer. This research arose from the idea that the maple solid wood with heterogeneous wood density and ray direction in the side edge would have uneven rheological property of violin bridge blank which is supposed to be pressed by the tension of strings. Experimentally, the compressive creep of bridge blank became smaller with the higher density of imported maple wood and showed clear density-dependence for the duration of load under the string tension of 5 kgf. Every bridge blank showed the behavior of primary creep stage(stress stabilization) having logarithmic regression creep curve with high correlation coefficient under the designed stress level. Even though the relationship between compressive creep and ray direction on the side edge of bridge was not so clear contrary to expectation, we could conclude that wood density and ray direction should be the quality decisive factors affecting the acoustical characteristics and performance of the bridge, the core member of violin-family bow instruments.

• Journal of the Korean Wood Science and Technology
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• 제11권1호
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• pp.5-11
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• 1983

This paper aims at gaining the informations atout the fibril angle at secondary walls of tracheids. The test specimens were taken from disks on stem wood of "Pinus koraiensis Sieb. et zucc". The method of measuring the fibirl angle was selected so-called "iodine method" that crystalline aggregates of iodine may be induced to form within the elongated interstices of the cellulose matrix of the secondary wall and that these elongated crystals are oriented parallel to the long axies of the fibrills of cellulose. The following conclusions may be drawn from the results of this investigation. 1) Gross average fibril angle was about $17.6^{\circ}$ on stem wood. 2) Its values seem to be greater for earlywood (avg.$19.8^{\circ}$) than for latewood tracheids (avg.$15.3^{\circ}$) in normal wood. 3) According to the increase of annual ring from pith to barks the orientation of fibril angle seems to be decrease gradually in normal wood. 4) In the case of height variation in trees the sample trees have a tendency to increase the orientation fibril angle to the increase of tree height in stem.