• 한국소음진동공학회논문집
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• 제21권8호
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• pp.768-773
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• 2011

This work presents an experimental investigation on vibration control of the active hybrid mount system for naval ships. To reduce unwanted vibrations, this paper proposes an active mount which consists of rubber element, piezostack actuator and inertial mass. The rubber element supports a mass. The piezostack actuator generates a proper control force and supply it to the mount system. To avoid being broken piezostack actuator, an actuator of the proposed mount is devised as an inertial type, in which a piezostack actuator is positioned between inertial mass and rubber element. Vibration control performances of the active mount system are evaluated via experiment. To attenuate the unwanted vibrations transferred from upper mass, the feedforward control is designed. In order to implement a control experiment, the active mount system supported by four active mounts is constructed. For realization of the controller, one-chip board is manufactured and utilized. Subsequently, vibration control performances of the proposed active mount system are experimentally evaluated in frequency domains.

• Journal of Astronomy and Space Sciences
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• 제26권1호
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• pp.47-58
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• 2009

In this study, a Hardware-In-the-Loop (HIL) simulator using thrusters is developed to validate the spacecraft attitude system. To control the attitude of the simulator, eight cold gas thrusters are aligned with roll, pitch and yaw axis. Also linear actuators are applied to the HIL simulator for automatic mass balancing to compensate the center of mass offset from the center of rotation. The HIL simulator consists of an embedded computer (Onboard PC) for simulator system control, a wireless adapter for wireless network, a rate gyro sensor to measure 3-axis attitude of the simulator, an inclinometer to measure horizontal attitude, and a battery set to supply power for the simulator independently. For the performance test of the HIL simulator, a bang-bang controller and Pulse-Width Pulse-Frequency (PWPF) modulator are evaluated successfully. The maneuver of 68 deg. in yaw axis is tested for the comparison of the both controllers. The settling time of the bang -bang controller is faster than that of the PWPF modulator by six seconds in the experiment. The required fuel of the PWPF modulator is used as much as 51% of bang-bang controller in the experiment. Overall, the HIL simulator is appropriately developed to validate the control algorithms using thrusters.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.2286-2288
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• 2001

In this paper, a drive system of induction motor with high performance is realized on the viewpoint of the design and experiment, using the DSP (TMS320F240). The speed controller for induction motor drive system is designed on the basis of a neuro-fuzzy network. The neuro-fuzzy controller acts as a feed-forward controller that provides the right control input for the plant and accomplishes error back-propagation algorithm through the network. The proposed network is used to achieve the high speedy calculation of the space vector PWM (Pulse Width Modulation) and to build the neuro-fuzzy control algorithm, for the real-time control. The proposed neuro-fuzzy algorithm on the basis of DSP shows that experimental results have good performance for the precise speed control of an induction motor drive system. It is confirmed that the proposed controller could provide more improved control performance than conventional v/f vector controllers through the experiment.

• 생물환경조절학회지
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• 제13권4호
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• pp.245-250
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• 2004

본 연구는 조조가온기간이 시설오이의 생육과 수량 및 난방부하에 미치는 영향을 구명하고자, 일출전에 난방온도를 올려서 $12^{\circ}C$에서 $16^{\circ}C$로 올려서 가온하는 기간을 2시간, 1시간 및 0시간을 비교하였다. 보온커텐을 열기 직전$(08:50\~09:00)$의 엽온은 조조가온을 하지 않는 것에 비해 1시간 가온이 $3.3^{\circ}C$, 2시간 가온이 $4.1^{\circ}C$각각 높았다. 오이 잎의 광합성, 기공전도도 및 증산량은 2시간 조조가온이 가장 좋았으나 1시간 가온과의 차이가 근소하였고 조조가온을 하지 않은 것은 현저히 감소하였다. 오이 잎의 무기성분함량은 유의적 차이는 없었으나 2시간, 1시간, 0시간 순으로 높은 경향이었다. 정식 이후의 초기생육은 1시간과 2시간 가온이 비슷하게 빨랐으나 조조가온을 하지 않는 것은 현저히 저조하였다. 과실 수량은 조조가온을 하지 않는 것에 비해 1시간 가온이 $11\%$, 2시간 가온이 $15\%$ 각각 증가되었다. 연료소모량은 조조가온하지 않는 것에 비해 1시간 가온이 $12\%$, 2시간 가온이 $22\%$ 각각 많았다. 생산물의 증수량과 연료소모량을 감안할 때 조조 가온하지 않는 것에 비해 가온한 것이 경영상 유리하였다.

• 한국잡초학회지
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• 제16권2호
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• pp.108-113
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• 1996

건답직파답(乾畓直播畓)에서 중요 우점초종(優點草種)인 피를 전년도에 방제시(防除時) 다음해 잡초발생(雜草發生) 생태변화(生態變化)와 직파답(直播畓)에 발생이 증가(增加)되고 있는 사마귀풀의 효과적(效果的)인 방제연구(防除硏究)를 위해 수행(遂行)한 시험결과(試驗結果)를 요약(要約)하면 다음과 같다. 1. 전년도 출수전(出穗前) 피를 완전히 방제(防除)한 구는 무방제구에 비하여 총(總) 잡초발생량(雜草發生量)은 파종후(播種後) 30일에 47.7%, 파종후(播種後) 60일에 7.8%가 감소(減少)하였다. 초종별(草種別)로는 파종후(播種後) 60일에 피는 46.9% 감소(減少)하였으나 사마귀풀, 여뀌는 각각 231%, 11.8% 증가(增加)하였다. 2. 군락내(群落內) 발생초종의 다양성(多樣性) 정도를 나타내는 다양성(多樣性) 계수(係數)는 방제구에서 낮았으며 방제구에서는 피의 우점도(優點度)가 떨어진 반면 특히 사마귀풀의 우점도(優點度)가 높아졌다. 3. 사마귀풀은 대체로 파종후(播種後) 40일 전후부터 벼 생육(生育)에 영향을 주었고, 사마귀풀 $m^2$당 300본 및 700본 구는 무발생구(손제초구)대비 수수가 61-72% 적고 등숙비율(登熟比率)이 5-15% 떨어져 쌀 수량(收量)이 74-93% 감수(減收)되었다. 4. 수량성과 다른 잡초방제효과(雜草防除效果)를 고려한 사마귀풀의 효과적(效果的)인 방제방법(防除方法)은 Butachlor(파종후(播種後) 5일)와 Propanil/Molinate(파종후(播種後) 25일)를 체계처리(體系處理)와 파종후(播種後) 20일 Lgc 40863 + Pendimethalin의 일발처리(一發處理) 하는 것이 효과적(效果的)이라는 결과(結果)를 얻었다.

• 대한물리치료과학회지
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• 제9권3호
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• pp.107-119
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• 2002

Astrocyte, which shares the greatest part of the brain (about 25%), is a land of glial cell that composes the central nervous system along with microglia, ependymal cell and oligodendroglia. It has 7-9nm of fibers in its cytoplasma, which are composed of glial fibrillary acidic protein (GFAP) and vimentin. As for the functions of the astrocyte, it has, so far, been supposed that the astrocyte will play a cytoskeletal role in maintaining the structure of the cerebrum, play a role as a blood-brain barrier so that it can induce migration of the neuron in its development and substances in the blood cannot go into the nervous tissue, and a role of immunology and phagocytosis. However, it was revealed today that it will be a role in preventing expansion of injury by attaching itself to the connective tissue such as the vessel and the pia mater when the nervous tissue or the arachnoid is injured. Microcurrent stimulation can control current, on the basis of A unit. That is, with such devices using it, it is possible to sense, from the outside, the injured current(wound current) of the lesion and to change it into the normal current, thereby promoting the restoration of the cells. In order to examine the effects of microcurrent stimulation on the injured astrocytes in the rabbits, this study was conducted with 24 New Zealand White Rabbit as its subjects, which were divided into 8 animals of the experiment group and 16 animals of the control group. After the animals in the experiment group were fixed to the stereotaxic apparatus, their hair was removed and their premotor area(association area) perforated by the micro-drill for skull-perforation with the depth of 8mm from the scalp. In one week after the injury, 4 animals in the control group and 8 animals in the experiment group were sacrificed and examined with immunohistochemical method. And in three weeks, the remaining 4 animals in the control group and 8 animals in the experiment group were also sacrificed and examined with the same way. The conclusion has been drawn as follows : In the control group sacrificed in one week after the injury, the astrocytes somewhat increased, compared with the normal animals, and in the group sacrificed in three weeks after the injury, they increased more (p < 0.05). The experiment group A in one week showed a little increase, but there was no significant differences, but the experiment group in three weeks showed more increase, compared with the experiment group in one week (p < 0.05). The experiment group B in one week showed more increase than the control group or the experiment group A, and the experiment group in three weeks showed more increase than the experiment group in one week (p < 0.05). Among the astrocytes, fibrous astrocytes were mostly observed, increasing as they are close to the lesion, and decreasing as they are remote from it. The findings show that microcurrent can cause the astrocytes to proliferate and that it will be more effective to stimulate the cervical part somewhat remote from the lesion rather than to directly stimulate the part of the lesion. Thus, microcurrent stimulation can be one of the methods that can activate the reaction of astrocytes, which is one of the mechanism for treating cerebral injury with hemorrhage. Therefore, this study will be used as basic research data for promoting restoration of functions in the patient with injury in the central nervous system.

• 한국식생활문화학회지
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• 제18권3호
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• pp.202-210
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• 2003

The purpose of this study was to investigate the effects of dietary purple sweet potato(Ipomoea batatas) powder on serum lipid levels and antioxidative enzymes in normal and pretective effect on hepatotoxicity rats induced by carbon tetrachlolide. Four groups of rats (3-week-old inbred Sprague-Dawley male rats) were normal rats fed control diet(C), induced hepatotoxicity rats fed control diet(EC), normal rats fed purple sweet potato diet(P), and induced hepatotoxicity rats fed purple potato sweet diet(EP). Rats were induced by single injection of 50% carbon tetrachlolide(0.1 mL/100 g B.W., i.p.). The rats were fed ad libitum each of the experimental diet for 5 weeks. After 5 weeks the rats were sacrificed and activities of antioxidant enzymes and lipid peroxidation products were determined in their liver homogenates. But serum concentrations of lipid was not significant in all groups. Serum alanine aminotransferase(ALT/GPT) and aspartate aminotransferase(AST/GOT) of the EC and EP groups were heigher than the C and P groups. The hepatic glucose 6-phosphatase(G6Pase) activity of the group fed purple potato diet(P) was lower than the other groups(p<0.05). However, The glutathione peroxidase(GPx) activities was not statistically different between the groups. Renal glutathione S-transferase(GST) activity of the EC and EP groups were lower than the C and P groups(p<0.05). In conclusion, these results suggest that purple sweet potato is believed to be possible protective effect on hepatotoxicity rats induced by carbon tetrachlolide.

• 동의신경정신과학회지
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• 제9권2호
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• pp.45-51
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• 1998

Purpose : This study has an experiment on finding how Hyangbujapamultang advanced the learning and memory of rat to find the method to improve the failure of memory which is the symptom of dementia.Method : In the experiment, rats were divided the control group (14 rat) which medicate the excipient into the sample group (17 rat) which medicates Hyangbujapalmutang. And the learning ability test and the memorv test was practiced to using the task of radial arm maze.The learning ability test had the presupposition that, when a rat which frequents 8 tracks makes am error not exceeding one time for 3 days without a break, it passes the test.First experiment compared total days when the control group passed the test with total days when the sample group it.The memory test practiced after 24 hours when the learning ability test was over. When a rat frequents 4 tracks, the gates is cut off during 30 seconds. Here the number of error at the control group with that of the sample group.Result: In the learning ability test, the sample group needed 5.82${\pm}$0.37 days to pass the test and the control group needed 6.43${\pm}$0.67 days. In the memory test, the sample group errored 0.29${\pm}$0.37 times and the control group errored 1.86${\pm}$0.78 times.Conclusion : In the learning ability test, the sample group passed the test earlier than the control group, but any statistical correlationship couldn't be found in it. In the memory test, the sample group had the pregnant reduction of the number of error in comparison with the control group.

• Journal of Periodontal and Implant Science
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• 제32권1호
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• pp.213-224
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• 2002

The ultimate goal of periodontal disease therapy is to promote the regeneration of lost periodontal tissue, there have been many attempts to develop a method to achieve this goal, but none of them was completely successful. The purpose of this study was to compare the effects of treatment using BBP(R) with control treated by only modified Widman flap. 22 intrabony defects from 12 patients with chronic periodontitis were used for this study, 10 sites of them were treated with BBP(R) as experimental group and 12 site were treated by only modified Widman flap as control group. Clinical parameters including probing depth, gingival recession, bone probing depth and loss of attachment were recorded at 6 months later, and the significance of the changes was statistically analyzed. The results are as follows : 1. Probing depth of control(${\triangle}2.7{\pm}1.3mm$) and experimental group(${\triangle}3.6{\pm}1.8mm$) weres reduced with statistically significance(P<0.05), but this changes were not different between the two experiment, control group with statistically significance. 2. Gingival recession showed statistically significant increase in control group(${\triangle}2.1{\pm}1.2mm$)(P<0.05), but not in experimental group(${\triangle}0.5{\pm}0.7mm$), and this changes were different between the two experiment, control group with statistically significance(P<0.05). 3. Bone probing depth showed statistically significant decrease in experimental group(${\triangle}2.9{\pm}1.0mm$)(P<0.05), but not in control group(${\triangle}1.1{\pm}1.4mm$), and this changes were different between the two experiment, control group with statistically significance(P<0.05). 4. Loss of attachment showed statistically significant decrease in experimental group(${\triangle}3.1{\pm}1.7mm$), but not in control group(${\triangle}0.6{\pm}1.2mm$), and this changes were different between the two experiment, control group with statistically significance(P<0.05) On the basis of these results, treatment using BBP(R) improves the probing depth, bone probing depth and loss of attachment in intrabony defects.

• 조명전기설비학회논문지
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• 제28권2호
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• pp.60-69
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• 2014

This paper proposed the circulation current control scheme in the single phase inverter system. The load experiment of the power conversion system including the UPS usually uses the passive components such as resistors and inductors. Therefore, the energy consumption is serious problem. In addition, the system is out of order when it is installed in the local area, and the load experiment can not perform adequately after troubleshooting, because there is no the load equipment, and the power capacity is not enough in the local area. The paper does the research on the circulation current control scheme, it does not need the load equipment, and the load current can reuse as the input current of the equipment. Instead of the conventional method the voltage-voltage and voltage-current control scheme introduced the parallel converter concept is newly proposed, and the validity of the proposed control scheme is investigated by both simulation and experimental results.