• Animal Bioscience
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• 제34권6호
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• pp.949-956
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• 2021

Objective: This study was focused on the estimation of parameters of Wood's model and description of the lactation curve using the cows which were lactated over 24 months on the first lactation. Methods: The database included 1,333 pure-bred dairy Simmental primiparous cows which lactated for 24 months (732 days). The initial dataset entering the procedure of assessment of parameters of Wood's function included 35,826 milk yield records. Milk yield was recorded throughout lactation, with the earliest record taken on day 6 and the latest on day 1,348 of lactation. This dataset was used for the assessment of parameters a, b, c of Wood's model using the non-linear statistical procedure. These parameters were estimated for different length of lactation. The assessed parameters were used for calculation of some characteristics of lactation curves. Results: The lowest value of a parameter (15.2317) of Wood's model of lactation curve was found out in lactations up to 305 days long, contrary to b and c parameters which were highest in those lactations (0.1029 and 0.0015, respectively). The maximum value of a parameter (17.4329) was found out in lactations up to 640 days long, unlike b and c parameters which were minimal in those lactations (0.0603 and 0.0010, respectively). Conclusion: It can be concluded that the parameters of Wood's model and the shape of lactation curve are changing with the growing number of milk yield records. Also, the assessed parameters revealed a significant milk production potential after 305 days of lactation.

• 한국가구학회지
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• 제24권3호
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• pp.273-285
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• 2013

The bent wood technique has been used for making the bow, the musical instruments and the wagon wheel, The Winsor chair of England in 1730's was the first Lfurniture product by using this method. This method was spread out by Michael Thonet in Austria after the Industrial Evolution. Early making technique of Winsor chair was relatively easy, but Michael Thonet's bent chair was mass produced by the machine and launched the revolution in the industrial furniture. 20th-Century European furniture designers applied the method of layering and forming plywood to bent chairs, enhanced the function and conformability. The bent chair had a big impact on modern chair design. The bent chair has the formative beauty and convenience from the character of softness and colors of wooden materials and has been developed variously by furniture designers. This study is a new approach to use Dyed-Gathered Wood with various colors and patterns as a material of the bend wood. First, bent wood with the Dyed-Gathered Wood enhances a close texture of wooden material textures instead of coating the surface. Second, flexibility of the bent wood with the Dyed-Gathered Wood enables wood bending techniques. Lastly, the Dyed-Gathered Wood is made with relatively cheap woods, replaces expensive imported woods which cause product price rise. This method enables a material cost saving and a stable supply of material.

• 한국산학기술학회논문지
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• 제16권10호
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• pp.6959-6968
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• 2015

이 연구는 기존의 목제품 수급모형(FOSMO2013)을 갱신하고, 제품별로 중장기적인 수요와 공급을 전망하는데 목적이 있다. 목제품 시장 수급모형은 주요 제품인 제재목, 합판, 파티클보드, 섬유판, 펄프 등으로 한정하였다. 각각의 제품에 대해 공급함수, 수입수요함수, 수요함수 등을 최신 자료를 이용하여 갱신하였다. 외생변수 가운데 하나인 세계 목재 및 목제품에 대한 가격 전망치는 Buongiorno 등(2012)의 연구결과를 적용하였다. Buongiorno의 연구는 기후변화에 관한 정부간 협의체(IPCC) 시나리오 3개(A1B, A2, B2)와 연료목재 수요에 대한 가정을 변경한 시나리오(A1B_LF)를 추가하여 전망결과를 발표하였는데, 본 연구의 전망치도 이와 같은 시나리오를 반영하여 2050년까지 총 4개의 시나리오에 따른 결과를 전망하였다. 전망 결과 국내 목재 및 목제품에 대한 장기 전망치는 시나리오와 제품별 차이는 있지만 대체적으로 생산은 감소하고 수입은 증가할 것으로 예상되었다.

• Journal of the Korean Wood Science and Technology
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• 제31권3호
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• pp.24-29
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• 2003

This research was performed to investigate the diffusivity of borate rods in radiata pine (Pinus radiata D. Don) conditioned to 40 percent moisture content (MC). The deepest penetration of boron were observed in the longitudinal direction, followed by the radial and the tangential directions. The boron loading on the wood face adjacent to the borate rod tended to increase with diffusion time in all directions. To mathematically quantify boron diffusion, the diffusion coefficient of boron was determined using Boltzmann's transformation by assuming that it was a function of concentration only. The values of the longitudinal diffusion coefficients were between 1.3×10^-8 cm²/sec and 9.2×10^-8 cm²/sec. The radial diffusion coefficients were between 1.4×10^-8 cm²/sec and 9.5×10^-8 cm²/sec, and the tangential diffusion coefficients were between 5.2×10^-9 cm²/sec and 1.3×10^-8 cm²/sec. The differences of diffusion coefficients between the longitudinal direction and the radial direction were slight, although their concentration profiles were markedly different. This indicates that the amount of boron loading on the wood face adjacent the borate rod is one of the most important factor for boron penetration in wood with low MC.

• Journal of the Korean Wood Science and Technology
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• 제20권1호
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• pp.72-78
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• 1992

지진과 관련있는 하중 속도에서 damping을 측정하기 위하여 합판과 목재 사이에 한개의 못을 사용한 접합에 대하여 조사 했다. 조사된 하중은 sine function 의 15Hz와 ASTM하중 속도 사이에서 행했다. Damping 율은 4Hz까지의 하중 속도에서는 증가를 보였으며 그후 15Hz 까지는 점진적으로 감소하였다. 강성은 높은 하중 범위에서 slip moduli가 지속적으로 증가 하였다. 낮은 하중 범위에서 2.5Hz까지 증가 하였으며 그후는 감소 하였다. Damping 율과 slip modulus는 하중 속도와 상관 관계가 낮은 반면 work capacity와 dissipated energy는 높은 상관 관계를 보았다.

• Journal of the Korean Wood Science and Technology
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• 제50권5호
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• pp.365-374
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• 2022

Today, commercialized Hinoki cypress cubes are used for fragrance, humidification, and pillows in Korea. In this study, the sound absorption ability of Hinoki cypress (Chamaecyparis obtusa) cubes was examined. The three groups of Hinoki cypress cubes were prepared depending on their dimension (L: 9 × 9 × 9, M: 7 × 7 × 7, S: 4 × 4 × 4 mm). Their sound absorption coefficient was examined after filling 6, 8, 10, and 12 cm height in impedance tubes, respectively. Overall, the sound absorption ability depending on dimension was superior in the M group compared to the L and S groups. Also, as the filling height increased, the sound absorption capacity increased. In sum, noise reduction coefficients (NRC) of all Hinoki cypress cubes were 0.41-0.59. Thus, this research found that Hinoki cypress cubes have a sound-absorbing function.

• Journal of the Korean Wood Science and Technology
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• 제45권6호
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• pp.836-845
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• 2017

Gravimetric method is usually used to evaluate air-dry density, which is governing physical or mechanical properties of wood. Although it had high evaluation accuracy, the method is time consuming process. Thus, this study was conducted to estimate air-dry density of wood with high accuracy by using polychromatic X-ray and digital detector as alternative of gravimetric method. To quantify polychromatic X-ray projection for evaluating air-dry density, Lambert-Beer's law with the integral value of probability function was used. The integral value was used as weighting factor in the law, and it was determined by conducting simple test at various penetration depths and tube voltage. Mass attenuation coefficient (MAC) of wood also calculated by investigating polychromatic X-ray projection according to species, penetration depth and tube voltage. The species had not an effect on change of MAC. Finally, an air-dry density of wood was estimated by applying the integral value, MAC and Lambert-Beer's law to polychromatic X-ray projection. As an example, the relation of the integral value (${\alpha}$) according to penetration depth (t, cm) at tube voltage of 35 kV was ${\alpha}=-0.00091t{\times}0.0184$ while the regression of the MAC (${\mu}$, $cm^2/g$) was ${\mu}=0.5414{\exp}(-0.0734t)$. When calculation of root mean squared error (RMSE) was performed to check the estimation accuracy, RMSE at 35, 45 and 55 kV was 0.010, 0.013 and $0.009g/cm^3$, respectively. However, partial RMSE in relation to air-dry density was varied according to tube voltage. The partial RMSE below air-dry density of $0.41g/cm^3$ was $0.008g/cm^3$ when tube voltage of 35 kV was used. Meanwhile, the partial RMSE above air-dry density of $0.41g/cm^3$ decreased as tube voltage increased. It was conclude that the accuracy of estimation with polychromatic X-ray and digital detector was quite high if the integral value and MAC of wood were determined precisely or a condition of examination was chosen properly. It was seemed that the estimation of air-dry density by using polychromatic X-ray system can supplant the gravimetric method.

• Journal of the Korean Wood Science and Technology
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• 제50권2호
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• pp.81-92
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• 2022

To analyze the relationship between climatic factors (mean monthly temperature and total precipitation) and tree-ring growths of Pinus densiflora S. et Z. from National Parks (according to region) of the Korea, 20 trees were sampled from 13 National Parks. Only trees that were successfully cross-dated were used for dendrochronological analysis, and at least 11 trees were included. The tree-ring chronology of Mt. Bukhan (covering the shortest period of 1917 - 2016 [100 years]) was assessed, as well as that of Mt. Seorak (covering the longest period of 1687 - 2017 [331 years]). After cross-dating, each ring width series was double-standardized by first fitting a logarithmic curve and then a 50-year cubic spline. The relationships between climate and tree-ring growth were calculated with response function analysis. The results show a significant positive correlation between a given year's February-March temperature, May precipitation levels, and tree-ring growth. It indicates that a higher temperature in early spring and precipitation before cambium activity are important for radial growths of Pinus densiflora in the Korea.

• Journal of the Korean Wood Science and Technology
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• 제33권1호통권129호
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• pp.63-76
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• 2005

목재문화는 시멘트문화를 대체하는 새로운 패러다임으로서, 목재문화가 학문적 체계를 갖추기 위하여는 공학적 연구만이 아니라 사회학적 연구도 병행되어야 한다. 본 연구는 아직 국내외적으로 전혀 시도된 바가 없는 목재문화의 사회학적 측면을 구조 기능적, 체계 기능적, 갈등적, 사회 변동적 측면에서 사회학적으로 연구하고 우리나라의 사례를 분석함으로써 목재문화의 사회학적 접근방법을 제시하는데 목적이 있다. 구조 기능적 측면에서 보면 사회체계는 최상위의 인식체계, 그 다음의 제도체계, 생활체계, 기술체계의 4가지 부분체계로 이루어진다. 이들 부분체계는 목재문화 전체의 기능을 유지하기 위하여 당위성 타당성 현실성 발전성의 기능을 발휘한다. 체계기능적 측면에서 볼 때 목재문화체계는 목재 효용성의 인지와 전파과정에 따라 개인적 체계와 조직적 체계, 이 두 가지를 망라하는 사회적 체계의 3가지로 구성되며, 갈등측면에서 볼 때 사회는 목재문화와 시멘트문화의 갈등양상에 따라 고유의 목재문화는 쇠퇴하고 시멘트문화가 확산되는 사회, 시멘트문화가 쇠퇴하고 목재문화가 확산되는 사회, 고유의 목재문화와 시멘트문화가 균형을 이루는 사회로 구분된다. 이와 같은 목재문화의 유형을 문화변동의 측면에서 분류하면, 목재문화에서 시멘트문화로의 변동, 시멘트문화에서 목재문화로의 변동, 목재문화 자체의 변동으로 분류할 수 있다. 또한 변동수준에 따라 분류하면 미시적 변동, 중간적 변동, 거시적 변동으로 분류된다. 이상과 같이 목재문화를 사회학적으로 조명하는 새로운 접근방법과 공학적 연구가 함께 진행되어 빠른 시일내에 학계에서 "목재문화론" 또는 "목재문화학"이 체계적으로 정립되기를 바란다.

• Journal of the Korean Wood Science and Technology
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• 제40권6호
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• pp.370-377
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• 2012

잣나무(Pinus koraiensis S. et Z.)와 로지폴소나무(Pinus contorta Dougl)를 이용하여 열처리 목재를 제조한 후 처리조건에 따른 재색변화를 조사하였다. 반응표면분석법에 따라 설정된 9가지 처리조건(처리온도 : 170, 180, 200, 220, $230^{\circ}C$, 처리시간: 90, 120, 180, 240, 270 min.)에서 열처리 시편들을 제조하였으며, 색차계를 이용하여 재색을 측정한 후 흰개미 저항성을 평가하기 위하여 진주에 설치된 흰개미 시험장에서 6개월 동안 야외노출시험을 실시하였다. 처리온도와 처리시간이 증가함에 따라 명도가 감소하였으며 감소폭은 시간보다 온도에 의한 영향이 더 큰 것으로 나타났다. 미국국립표준국(National Bureau of Standards : NBS)에서 제시된 방식에 의해 평가된 색차를 처리온도와 처리시간의 함수로 표현한 반응표면분석모델은 잣나무의 경우 $R^2$의 값이 0.92, 로지폴파인의 경우 0.88로 열처리조건에 따른 색채의 예측가능성을 보여주었다. 6개월의 야외시험결과 열처리 조건에 상관없이 흰개미 가해가 심하게 발생된 것으로 나타났는데, 이는 제조된 열처리 목재의 흰개미 저항성이 야외에 사용하기에 적합하지 않다는 것을 보여준다.