• 한국기계가공학회지
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• 제14권2호
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• pp.14-18
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• 2015

In recent years, world is faced with a transportation energy dilemma, and the transportation is almost dependent on a single fuel - petroleum. However, Hybrid Electric Vehicle (HEV) technology holds more advantages to reduce the demand for petroleum in the transportation by efficiency improvements of petroleum consumption. Therefore, there is a trend that lower gear noise levels are demanded in HEV for drivers to avoid annoyance and fatigue during operation. And meshing transmission error (T.E.) is the excitation that leads to the tonal noise known as gear whine, and radiated gear whine is also the dominant source of noise in the whole gearbox. In this paper, the analysis of gear tooth profile and lead modification is firstly presented, and then, the different transmission error of no mesh misalignment and mesh misalignment under one loaded torque for the 1st gear pair of HEV gearbox was investigated and compared. At last, the appropriate tooth modification was used to minimize and compare the transmission error of the gear pair with mesh misalignment under the loaded torque.

• Structural Engineering and Mechanics
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• 제63권6호
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• pp.735-742
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• 2017

Steel cables as the most important components are widely used in the certain types of structures such as cable-supported bridges, but the long-span structures may result in an increase in fatigue under high stress and corrosion of steel cables. The traditional steel cable is becoming a more evident hindrance. Fiber Reinforced Polymer (FRP) cables with lightweight, high-strength are widely used in civil engineering, but there is little research in vibrational characteristics of FRP cables, especially on the damping characteristic. This article studied the two methods to evaluate dynamical damping characteristic of basalt FRP(BFRP) and glass FRP(GFRP) cables. First, the vibration tests of the B/G FRP cables with different diameter and different cable force were executed. Second, the cables forces were calculated using dynamic strain, static strain and dynamic acceleration respectively, which were further compared with the measured force. Third, experimental modal damping of each cables was calculated by the half power point method, and was compared with the calculation by Rayleigh damping theory and energy dissipation damping theory. The results indicate that (1) The experimental damping of FRP cables decreases with the increase of cable force, and the trend of experimental damping changes is roughly similar with the theoretical damping. (2) The distribution of modal damping calculated by Rayleigh damping theory is closer to the experimental results, and the damping performance of GFRP cables is better than BFRP cables.

• Smart Structures and Systems
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• 제21권4호
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• pp.479-491
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• 2018

Shape memory alloys (SMA) exhibit superelasticity which refers to the capability of entirely recovering large deformation upon removal of applied forces and dissipating input energy during the cyclic loading reversals when the environment is above the austenite finish temperature. This property is increasingly favored by the earthquake engineering community, which is currently developing resilient structures with prompt recovery and affordable repair cost after earthquakes. Compared with the other SMAs, NiTi SMAs are widely deemed as the most promising candidate in earthquake engineering. This paper contributes to evaluate the seismic performance of properly designed concentrically braced frames (CBFs) equipped with NiTi SMA braces under earthquake ground motions corresponding to frequently-occurred, design-basis and maximum-considered earthquakes. An ad hoc seismic design approach that was previously developed for structures with idealized SMAs was introduced to size the building members, by explicitly considering the strain hardening characteristics of NiTi SMA particularly. The design procedure was conducted to compliant with a suite of ground motions associated with the hazard level of design-basis earthquake. A total of four six-story CBFs were designed by setting different ductility demands for SMA braces while designating with a same interstory drift target for the structural systems. The analytical results show that all the designed frames successfully met the prescribed seismic performance objectives, including targeted maximum interstory drift, uniform deformation demand over building height, eliminated residual deformation, controlled floor acceleration, and slight damage in the main frame. In addition, this study indicates that the strain hardening behavior does not necessarily impose undesirable impact on the global seismic performance of CBFs with SMA braces.

• 한국융합학회논문지
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• 제7권1호
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• pp.137-143
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• 2016

본 연구는 쥐눈이콩을 주재료로 하는 당뇨의 식이요법에 활용할 수 있는 간편 편이식을 개발하고자 계획하였고 그 첫 단계로 고처방을 기초로 하여 미숫가루를 고안하였다. 동양의 기미론을 기본으로 그 효능을 분석하고 동시에 영양성분을 분석한 후 동 서 식품영양학적으로 그 효능을 비교, 고찰하여 당뇨의 식 의약 치료에 있어 활용가치를 판단해 보았다. 본 연구는 식품을 기미론(氣味論)적으로 분석하여 약선식료학 연구를 위한 기초자료를 확보하고 동시에 식품영양분야에서 식품효능 접근 방법과 원활한 접목을 위한 자료를 제시할 수 있을 것이라 사료된다. 또한 향후 식품의 효능이나 섭취방안에 대한 올바른 개념을 정립하여 식품 효능에 대한 인식 전환의 계기가 되어 동양에서 바라보는 식품의 섭취효능을 이해하는데 기초자료가 될 수 있으리라 판단된다. 한편, 본 연구자들은 본 연구에서 고안한 미숫가루의 보간익신(補肝益腎) 효능을 객관적으로 판단해 보고자 임상실험을 진행하여 당뇨의 식 의약치료에 활용할 수 있는 가치를 계속적으로 연구 보고하고자 한다.

• Korean Journal of Acupuncture
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• 제26권1호
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• pp.27-40
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• 2009

Background : Qigong is an energy-healing intervention used to prevent and cure ailments and to improve health through regular practice. Although qigong-neither itself nor its postulated mechanism of action-are within the paradigm of modern Western medical science, its effects on the human body could be possible. Objectives : This study aims to review the bibliography, biological responses and therapeutic effects of Qigong. In the process, this review will grasp trends in this field of studies and will direct further researches into the right direction. Method : The computerized Korean databases were searched from their respective inceptions up to January 2008. The search terms used were 'qi', 'qigong', 'doin', 'training', 'bioenergy', 'life nurturing' and random or Korean language terms related to qigong. Several specialized journals were also manually searched for relevant articles. Result : Since the 1990s, Qigong papers in the Korean Literature are increased. The articles on Korean traditional medicine had been published more than those on physical education or nursing etc. However, since the majority of the trials determine questionnaire, it was difficult to determine the efficacy of a specific intervention. The methodological quality of the trials was generally low (Jadad score: mean, 1.3; range, 1 to 4), questioning their reliability. Conclusions : More profound studies for Qigong are needed. Further rigorous clinical trials with more objective outcome measures that include sham procedures should be performed. Specifically, we think it should be clinical studies and qualitative research methods for evaluation are needed.

• 동의생리병리학회지
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• 제22권4호
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• pp.954-959
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• 2008

Qigong is one energy-healing intervention used to prevent and cure ailments and to improve health through regular practice. Although qigong-neither itself nor its postulated mechanism of action - are within the paradigm of modern Western medical science, effects on the human body could be possible. This study aims to review the bibliography, biological responses and therapeutic effects of Qigong. In the process, this review will grasp trends in this field of studies and will direct further researches into the right direction. The computerized Korean databases were searched from their respective inceptions up to January 2008. The search terms used were 'qi', 'qigong', 'doin', 'training', 'bioenergy', 'life nurturing' and random or Korean language terms related to qigong. Several specialized journals were also manually searched for relevant articles. Since the 1990s, Qigong papers in the Korean Literature is increased. Published 152 papers on Korean medicine were more than Physical education and Nursing. 78 papers published in The Journal of Korean Academy of medical Gi-gong are the best in many areas related to Korean medicine. Most people have submitted papers related to Qigong was Lee Gi-nam. The depth study for the each Qigong is needed. Specifically, I think it should be a clinical studies and qualitative research methods for evaluation are needed.

• Journal of the Korean Wood Science and Technology
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• 제48권6호
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• pp.869-877
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• 2020

The power consumption in the low consistency (LC) refining is an important indicator for the optimal control of the process and it is composed of the net power and the no-load power. The refining efficiency and process characterization of LC refining are directly affected by power consumption. In this paper, the effect of pulp consistency and average fiber length on the power consumption and refining efficiency were studied through the LC refining trials conducted by an experimental disc refiner. It is found that the curve of power-gap clearance can be divided into constant power section, power reduction section, and power increase section. And the no-load power and the adjustable domain of loading applied by the refining plates will increase as the increase of pulp consistency, while the increase of net power is larger than that of no-load power which makes the increasing of refining efficiency. Meanwhile, the adjustable domain of loading applied by the refining plates can be slightly improved by increasing the average fiber length, but its effect on the no-load power in the LC refining process can be neglected. The study of power consumption in LC refining is of positive significance for the proper selection of pulp properties in LC refining, in-depth exploration of refining mechanism, and energy consumption reduction in refining.

• 대한한의학원전학회지
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• 제21권3호
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• pp.297-306
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• 2008

Background : Gigong(氣功, Qigong) is one energy-healing intervention used to prevent and cure ailments and to improve health through regular practice. Although Gigong(氣功, Qigong) - neither itself nor its postulated mechanism of action - are within the paradigm of modern Western medical science, effects on the human body could be possible. Objectives : This study aims to review the bibliography, biological responses and therapeutic effects of Gigong. In the process, this review will grasp trends in this field of studies and will direct further researches into the right direction. Method : The computerized Korean databases were searched from their respective inceptions up to January 2008. The search terms used were 'Gi(氣, Qi)', 'Gigong(氣功, Qigong)', 'Doin(導引)', 'Training', 'Bioenergy', 'life nurturing' and random or Korean language terms related to Gigong. Several specialized journals were also manually searched for relevant articles. Result : Since the 1990's, Gigong papers in the Korean Literature is increased. Clinical research studies are among the most control design study. Research subjects are less patient than the general public. The most common treatment disease was Musculo-skeletal disorder Conclusions : The depth study for the each Gigong(氣功, Qigong) is needed. Specifically, I think it should be a clinical studies and qualitative research methods for evaluation are needed.

• Earthquakes and Structures
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• 제14권4호
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• pp.337-347
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• 2018

This paper presents some shaking table tests conducted on a 1/4-scaled model with 5-story steel reinforced concrete (SRC) spatial frame with irregular section columns under a series of base excitations with gradually increasing acceleration peaks. The test frame was subjected to a sequence of seismic simulation tests including 10 white noise vibrations and 51 seismic simulations. Each seismic simulation was associated with a different level of seismic disaster. Dynamic characteristic, strain response, acceleration response, displacement response, base shear and hysteretic behavior were analyzed. The test results demonstrate that at the end of the loading process, the failure mechanism of SRC frame with irregular section columns is the beam-hinged failure mechanism, which satisfies the seismic code of "strong column-weak beam". With the increase of acceleration peaks, accumulated damage of the frame increases gradually, which induces that the intrinsic frequency decreases whereas the damping ratio increases, and the peaks of acceleration and displacement occur later. During the loading process, torsion deformation appears and the base shear grows fast firstly and then slowly. The hysteretic curves are symmetric and plump, which shows a good capacity of energy dissipation. In summary, SRC frame with irregular section columns can satisfy the seismic requirements of "no collapse under seldom earthquake", which indicates that this structural system is suitable for the construction in the high seismic intensity zone.

• Asian-Australasian Journal of Animal Sciences
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• 제20권6호
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• pp.850-855
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• 2007

Leptin is the adipocyte-specific product of the obese gene and plays a major role in food intake and energy metabolism. Leptin research was mainly focused on mammalian species, but understanding of leptin and its function in poultry is very poor. In this study, the duck leptin gene was amplified using the reverse transcription-polymerase chain reaction (RT-PCR) from duck liver RNA. The cDNA fragment was inserted into the pET-28a expression vector, and the resulting plasmid was expressed in Escherichia coli BL21 (DE3). Experimental mice were given an intraperitoneal injection of 10 mg/kg leptin dissolved in phosphate buffered saline (PBS), while the control mice were injected with PBS. The effect of leptin on food intake, body weight and fatty deposition in mice was detected. Sequence analysis revealed that duck leptin had a length of 438 nucleotides which encoded a peptide with 146 amino acid residues. The sequence shares highly homology to other animals. The coding sequence of duck leptin was 84 and 86% identical to human and pig leptin nucleotides sequence. Highest identity was with the rat coding sequence (95%). The identity of the amino acid sequence was 84, 82 and 96% respectively compared to that of the human, pig and rat. Results of SDS-PAGE analysis indicated that a fusion protein was specifically expressed in E. coli BL21 (DE3). The purified product was found to be biologically active during tests. Continuous administration of recombinant duck leptin inhibited food intake. Despite the decrease of food intake, leptin significantly induced body weight and fatty deposition. These changes were accompanied by a significant down-secretion of plasma glucose, cholesterol, triglyceride and insulin levels in mice. The observations provide evidence for an inhibitory effect of leptin in the regulation of food intake and for a potential role of duck leptin in the regulation of lipogenesis.