• Journal of the Korean Wood Science and Technology
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• 제47권3호
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• pp.360-370
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• 2019

Woody crops cultivated in short-rotation coppices are attractive sources of lignocellulosic materials for bioethanol production, since they are some of the most abundant renewable resources. In this study, we evaluated the effects of the growth period on bioethanol production using short-rotation woody crops (Populus nigra ${\times}$ Populus maxiwiczii, Populus euramericana, Populus alba ${\times}$ Populus glandulosa, and Salix alba). The carbohydrate contents of 3-year-old and 12-year-old short-rotation woody crop branches were 62.1-68.5% and 64.0-67.1%, respectively. The chemical compositions of 3-year-old and 12-year-old short-rotation woody crop branches did not vary significantly depending upon the growth period. However, the 3-year-old short-rotation woody crop branches (glucose conversion: 26-40%) were hydrolyzed more easily than their 12-year-old counterparts (glucose conversion: 19-24%). Furthermore, following the fermentation of enzymatic hydrolysates from the crop branch samples (by Saccharomyces cerevisiae KCTC 7296) to ethanol, the ethanol concentration of short rotation coppice woody crops was found to be higher in the 3-year-old branch samples (~ 0.18 g/g dry matter) than in the 12-year-old branch samples (~ 0.14 g/g dry matter). These results suggest that immature wood (3-year-old branches) from short-rotation woody crops could be a promising feedstock for bioethanol production.

• Korean Journal of Acupuncture
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• 제30권2호
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• pp.88-96
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• 2013

Objectives : In the acupuncture treatment of Korean Medicine, the Tonifying or Purging depending on how many times the needle is rotated has been used widely. However, there is little evidence about the optimal number of rotation. This study, therefore, was aimed to investigate the optimal number of rotation. Methods : Heart rate variation was measured before and after exercise in 20 healthy adults. Acupuncture was performed at PC6 immediately after exercise according to the protocol of each group without remaining. Pre-exercise and post-exercise measurements were compared and the rotation number that produced statistically significant difference was investigated. Results : Significant differences were found in the heart rate variation and R-R interval Average, between non-rotation group (control) and both of 15 times rotation group of tonifying and 6 times rotation group of purging. Conclusions : Significantly effective number of rotation in the effect of PC6 on the HR and RRAv was 15 times in the tonifying and 6 in the purging respectively.

• Journal of Information Technology Applications and Management
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• 제14권1호
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• pp.137-144
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• 2007

In this paper, we propose a rotation resistant robust logo embedding watermarking technique. Geometric manipulations make the detection process very complex and difficult. Watermark embedding in the normalized image directly suffers from smoothing effect due to the interpolation during the image normalization. This can be avoided by estimating the transform parameters using image normalization angle and moments, instead of embedding in the normalized image. Conventional rotation resistant schemes that use full frame transform. In this paper we adopt DCT and calculate masking using a spatio-frequency localization of the $8{\times}8$ block DCT coefficients. Experimental results show that the proposed algorithm is robust against rotation process.

• 대한기계학회논문집B
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• 제28권4호
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• pp.467-474
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• 2004

A large-eddy simulation is performed for turbulent flow in a concentric annulus with the inner wall rotation at Re$\sub$Dh/=8900 for three rotation rates N=0.2145, 0.429 and 0.858. Main emphasis is placed on the inner wall rotation effect on near-wall turbulent structures. Near-wall turbulent structures close to the inner wall are scrutinized by computing the lower-order statistics. The anisotropy invariant map for the Reynolds stress tensor and the invariant function are illustrated to reveal the altered anisotropy in turbulent structure. Probability density functions of the splat/anti-splat process are explored to develop a sufficiently complete picture of the contributions of the flow events to turbulent production. The present numerical results show that the altered turbulent structures may be attributed to the centrifugal instability, which leads to the augmentation of sweep and ejection events.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.433-439
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• 2000

Reinforced concrete beams show increased ductile behavior when the compressive concrete is confined with transverse steel. In the inelastic range, the most variations of ductile behaviour are defined the equivalent length of the plastic hinge and the plastic hinge rotation. In an investigation to study the influence of such confinement, sixteen reinforced concrete beams were tested in flexure and the deflections noted at all stages of loading. For all the beams tested, the plastic hinge rotation have been computed and the effect of confinement on the same examined. The conclusions are summarized as follows: The equivalent lengths of the plastic hinge are ranged within the effective depth comparatively. The ability of the plastic hinge rotation of the reinforced concrete beams confined with transverse steel are enlarged when transverse reinforcement content are increased, but the spaces are more important as the shear force are largely increased.

• 한국운동역학회지
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• 제27권1호
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• pp.67-74
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• 2017

Objective: The purpose of this study was to apply a general linear model in statistics to marker position vectors used to study human joint rotational motion in biomechanics. Method: For this purpose, a linear model that represents the effect of the center of hip joint rotation and the rotation of the marker position on the response was formulated. Five male subjects performed hip joint functional motions, and the positions of nine markers attached on the thigh with respect to the pelvic coordinate system were acquired at the same time. With the nine marker positions, the center of hip joint rotation and marker positions on the thigh were estimated as parameters in the general linear model. Results: After examining the fitted model, this model did not fit the data appropriately. Conclusion: A refined model is required to take into account specific characteristics of longitudinal data and other covariates such as soft tissue artefacts.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 추계학술대회논문집
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• pp.103-106
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• 2004

The new rheology fabrication process has been developed to rheo die casting and rheo forming process. Thixoforming process has disadvantages in terms of induction reheating process, scrap recycling, loss of raw material and cycle time. Therefore, to reduce the number of process, new rheology fabrication process with specially designed the rotational barrel type equipment has been proposed to apply in various part productions. The barrel type equipment, which could continuously fabricate the rheology materil, was specially designed to have a function to control cooling rate, shear rate and temperature. During the continuous rotation of barrel with a constant temperature, the shear rate is controlled with the rotation speed. The barrel surface has both the induction heating system and the cooling system to control the temperature of molten metal. By using this system, the effect of the rotation speed and the rotation time on the microstructure was widely examined. The possibility for the rheoforming process was investigated with microstructural characteristic.

• Journal of Astronomy and Space Sciences
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• 제39권2호
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• pp.59-65
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• 2022

In this paper we propose a new perspective for explaining galaxy rotation curves. We conjecture that there is a gravitational moment of inertia which, together with gravitational mass, contributes to the gravitational potential. We substantiate a formula for the potential created by the moment of inertia. We validate our model by computing orbital rotation velocities for several galaxies and showing that computed rotation velocities correspond to the observed ones. Our proposed approach is capable of accounting for constant gas velocities outside of a galactic disc without relying on the dark matter hypothesis. Furthermore, it addresses several problems faced by the application of the dark matter hypothesis, e.g., the absence of inward collapse of dark matter into a galaxy, the spherical distribution of dark matter around galaxies, and absence of traces of the effect of dark matter in two ultra-diffuse galaxies, NGC 1052-DF2, and NGC 1052-DF4.

• 한국조리학회지
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• 제16권4호
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• pp.163-176
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• 2010

무한경쟁시대의 경쟁력 우위 확보라는 측면에서 기업의 최고 경영자와 관리자들은 조직 구성원의 가치와 그 중용성에 대한 인식이 매우 증대되고 있다. 호텔업계에서도 철저히 차별화, 특성화된 서비스를 제공하기 위해 조직 구성원의 가치와 그 중요성에 대해 역설하고 있지만, 여전히 많은 비용과 노력을 들여 우수 인재를 채용하더라도 처음의 업무 배치 이후로는 지속적인 개인 관리를 통한 능력 개발에는 소홀하고 있음을 인할 수 없는 것이 현 실정이다. 따라서 본 연구에서는 종사원들은 어떤 부분의 영향력 때문에 직무 순환을 원하고, 또한 반대로 원하지 않는지에 대해 파악해 보고, 직무 순환이 동기 부여에 영향을 미치는지, 동기 부여는 직무 만족에 직접적이고 큰 영향력을 발휘하는지에 대한 것을 파악하고자 하는 것이 이 연구의 궁극적인 목적이다. 본 연구 결과, 직무 순환의 효율성과 절차는 모두 동기 부여에 유의한 영향을 주는 것으로 나타났으며, 종사원들은 원활한 직무 순환으로 인해 적성에 맞는 적재적소의 배치 수단이 되기 위해 정기적인 직무 순환이 이루어지길 원하는 것으로 나타났다. 또한, 동기 부여는 직무 만족의 성취감, 복리후생, 상사와 동료와의 관계에 모두 유의한 영향을 주는 것으로 나타났으며, 특히 종사원들은 직무로 인한 성취감과 자부심을 느낄 때 직무 만족이 매우 높은 것으로 나타났다. 본 연구의 한계점은 직무 순환이라는 것 자체가 비용과 시간이 소요되는 인사상의 민감한 부분이었던 관계로 선행 연구의 절대적인 부족으로 좀 더 다양한 자료를 활용할 수 없었다는 점과 설문조사가 서울 시내 특급 호텔 F&B 종사원들을 위주로 이루어져서 전체적인 호텔산업을 대변하지 못했다는 점이다.

• 간호행정학회지
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• 제5권2호
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• pp.225-235
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• 1999

This study was conducted to offer a basic material for effective human resource management of nurses by studying correlations among inter-department rotation, job motivation and organizational commitment. For this study 159 nurses in a medical college hospital were surveyed. Organization Assessment Instrument(Van de Ven. 1980) and Organizational Commitment Questionnaire (Mowday, 1979) were used. SPSS was used to analyze the data. The results of this study are as follows : 1. Nurses who had been rotated to other departments showed higher motivation scores than those who had not. 2. Nurses who had been rotated also indicated higher organizational commitment scores than those who had not. 3. There was significant positive correlations among nurse's age, job motivation and organizational commitment of nurses. 4. There was significant positive correlations among nurse's experience, job motivation and organizational commitment of nurses. 5. Inter-department rotation times were significant positive correlation with job motivation. 6. "The sense of achievement perceived form performing one's duty" was the most important criteria that nurses consider in measuring their job motivation. As to the criteria for inter-department rotation, some respondents stated that it is needed when "current assignments are not suited for particular individuals" and such rotations would job motivation and elevate the morale of nurses involved." Many opposed using the rotations as a "means of reprimanding individuals." In conclusion, inter-department rotation has a positve effect on the nurse's job motivation and organizational commitment, so regular inter-department rotation have to be recommended to nurses who want rotation.