대기온도가 Diesel Cycle의 성능에 미치는 영향에 관한 이론적 고찰

장성운 충주대학교 2006 한국교통대학교 논문집 Vol.41 No.-

In internal Diesel combustion engine, The change of air temperature is change the density of air in the stoke volume to Diesel engine. The influence of power and efficiency is change according to the atmosphere- temperature of air. For calculating, decided the Diesel engine scale is 2000cc and 4cylinders mechanical compression ratio is 18 of Diesel engine. Our country, Atmosphere-temperature change is -20℃ in winter to 40℃ in summer. The density of air increase by the temperature drop and decrease by the temperature rises. Density change of air is appear mass change to the stroke volume in Diesel engine. The mass change is change the compression ratio of Diesel. engine. The compression ratio change is change the thermal efficiency and power of Diesel engine. In atmosphere-temperature -20℃, Compression ratio change 20.687 and thermal efficiency change 66.05%. In atmosphere-temperature 40℃, Compression ratio change 16.913 and thermal efficiency change 63.21%. The Compression ratio and thermal efficiency are increase to the low temperature. The results are as follows, 1. The change of atmosphere temperature is change the density and mass of air and influence the power and thermal efficiency to the Diesel engine. 2. For increasing the mass of intake air to influenced the power and thermal efficiency must be drop the temperature of intake air 3. For drop the temperature of intake air, intake manifold must be set ahead of engine and order side of exhaust manifold.

A Study on the Correlation of Left Atrial Volume Change according to Left Ventricular Contraction in Atrial Fibrillation

Sung Kwan Kim,Hee Chang Chae,Choong Beom Seo,Eun Hee Seo,Chang Min Dae,Tae Eun Kim 대한CT영상기술학회 2022 대한CT영상기술학회지 Vol.24 No.1

The purpose of this study was to increase accuracy and success rate of radiofrequency catheter ablation by analysis of left atrial volume change relative to left ventricular volume change and left atrial diameter change relative to left atrial volume change. 20 patients with normal heart rhythm were set as the control group, and 20 patients with diagnosed atrial fibrillation were set as the experimental group. The cardiac cycle was divided into 10 stages ranging from 0% to 90%, and left ventricular volume, left atrial volume, left atrial diameter, pulmonary vein diameter were measured for each group. the correlation between the left ventricular volume and the left atrial volume was analyzed, and the correlation between the left atrial volume and left atrial diameter was analyzed. The diameter of the pulmonary veins was measured. As a result of analyzing the correlation between left ventricular volume and left atrial volume through Spearman correlation, the control group showed a negative correlation.(P<0.001) The experimental group were not correlated.(P=0.075) As a result of analyzing the correlation between the left atrial volume and the left atrial diameter, both groups showed a positive correlation.(P<0.001) As a result of analyzing the diameter of the pulmonary vein by Wilcoxon signed-rank test, both groups showed a significant difference in the maximum diameter and the minimum diameter.(P<0.001) Because the volume and diameter of the left atrium in patients with atrial fibrillation change irregularly, the radiologist check all cardiac cycle and reconstruct to increase the accuracy and success rate of radiofrequency catheter ablation.

Correlation between skeletal and dental changes after mandibular setback surgery-first orthodontic treatment

Chang-Hoon Rhee,Youn-Kyung Choi,Yong-Il Kim,Seong-Sik Kim,Soo-Byung Park,Woo-Sung Son 대한치과교정학회 2015 대한치과교정학회지 Vol.45 No.2

Objective: To investigate skeletal and dental changes after application of a mandibular setback surgery-first orthodontic treatment approach in cases of skeletal Class III malocclusion. Methods: A retrospective study of 34 patients (23 men, 11 women; mean age, 26.2 ± 6.6 years) with skeletal Class III deformities, who underwent surgery-first orthodontic treatment, was conducted. Skeletal landmarks in the maxilla and mandible at three time points, pre-treatment (T0), immediate-postoperative (T1), and post-treatment (T2), were analyzed using cone-beam computed tomography (CBCT)-generated half-cephalograms. Results: The significant T0 to T1 mandibular changes occurred ?9.24 ± 3.97 mm horizontally. From T1 to T2, the mandible tended to move forward 1.22 ± 2.02 mm, while the condylar position (Cd to Po-perpendicular plane) shifted backward, and the coronoid process (Cp to FH plane) moved vertically. Between T1 and T2, the vertical dimension changed significantly (p < 0.05). Changes in the vertical dimension were significantly correlated to T1 to T2 changes in the Cd to Po-perpendicular plane (r = ?0.671, p = 0.034), and in the Cp to FH plane (r = 0.733, p = 0.016), as well as to T0 to T1 changes in the Cp to Poperpendicular plane (r = 0.758, p = 0.011). Conclusions: Greater alterations in the vertical dimension caused larger post-treatment (T2) stage skeletal changes. Studying the mandibular position in relation to the post-surgical vertical dimension emphasized the integral importance of vertical dimension control and proximal segment management to the success of surgery-first orthodontic treatment.

Diagnostic Significance of Brainstem Auditory Evoked Potentials in Microvascular Decompression of Patients with Hemifacial Spasm or Trigeminal Neuralgia

( Sang-koo Park ),( Sung-hyuk Lim ),( Chan-woo Park ),( Jin-woo Park ),( Sung-ho Chang ),( Keun-hye Park ),( Hae-ja Park ),( Ji-hye Song ),( Dong-ok Uhm ),( Ki-bong Kim ) 대한임상검사과학회 2011 대한임상검사과학회지(KJCLS) Vol.43 No.1

The purpose of this study was to analyse brainstem auditory evoked potentials (BAEP) wave change data during microvascular decompression (MVD). The nerve function of Cranial Nerve VIII is at risk during MVD. Intraoperative monitoring of BAEP can be a useful tool to decrease the danger of hearing loss. Between January and December 2009, 242 patients had MVD for hemifacial spasm (HFS) and trigeminal neuralgia (TN). Among intraoperative BAEP changes, amplitude of V-V’ was the most frequently observed during cerebellar retraction and decompression step of the MVD procedure. 138 patients (57%) had no BAEP change while 104 patients (42.98%) had BAEP change. 69 patients (28.5%) had Type A-I, 16 patients (6.6%) had Type A-II, 5 patients (2.1%) had Type B, and 13 patients (5.37%) had Type C. MVD is a surgical procedure to relieve the symptoms (e.g. pain, muscle twitching) caused by compression of a nerve by an artery or vein. During BAEP intraoperative monitoring, the surgical step is important in interpreting the changes of wave V. Several potential mechanisms of injury may affect the cochlear nerve, and complete loss of BAEP is often associated with postoperative hearing loss. Intraoperative BAEP monitoring may provide an early warning of hearing disturbance after MVD.

고양이 소뇌 치상핵 자극에 따른 전경골근의 근전도 변화

성재훈,김문찬,강준기,최창락 대한신경외과학회 1994 Journal of Korean neurosurgical society Vol.23 No.7

Through the use of stereotactic neurosurgical operation, some authors have employed chronic electrical stimulation of the dentate nucleus reduce spasticity and each trial on spastic patients has show marked clinical improvement. We investigated the eletrophysiological changes of cats after stereotactic electrical stimulation of the dentate nucleus to elucidate the possibility of clinical application and to evaluate the clinical results The M-wave is an initial response and the F-wave is a late response in the electromyography of a muscle, which is stimulated by its original controlling nerve itself. There is evidence that the sue of the F-wave is dependent on motor neuron excitability and its amplitude is increased significantly at spastic condition. If such a relationship exists, procedures which are cam& out to relieve spasticity might be exerted to change the F-wave sue and thus it might be possible to use the F-wave as an objective monitor during electrical stimulation of the dentate nucleus. We investigated this possibility in experiments on 10 cats weighing betHieen 27kg and 4.4kg. We studied the change% of M and F waves, recorded in EMG, after stereotactic stimulation to cerebellar dentate nucleus in cats. The results were as follows 1) The change of mean value of M-wave amplitude was not significant(contro1 group, 3591 ± 1029μV stimulation group, 3424± 927μV, 00.05). 2) The mean value of F-wave amplitude was significantly reduced about 56.7% after the dentate stimulation(contro1 p u p , 443.2± 119μV stimulation p u p , 251.3±99.4μV, P<0.05). 3) The F/M ratio also significantly reduced about 56.8% after the dentate stimulation(contro1 group, 12.5±1.9%, stimulation group, 7.1± 1.2%, P<0.05). Our experimental results demonstrated that the dentate stimulation markedly decreased the sue of F-wave amplitude and F/M ratio in the experimental cats and we concluded that theseelectrophysiological changes can be applied as a parameter of clinical evaluation of electrical dentate stimulation for the spasticity.

금연실천단계의 영향변인에 대한 연구

장성옥,박창승 고려대학교 2001 간호학논집 Vol.3 No.-

대기온도가 Otto Cycle의 성능에 미치는 영향에 관한 이론적 고찰

장성운 忠州大學校 2005 한국교통대학교 논문집 Vol.40 No.2

In internal gasoline combustion engine, The change of air temperature is chage the density of air in the stoke volume to gasolive engine. The influence of power and efficiency is change according to the atmosphere-temperature of air. For calculating, decided the engine scale Engine stroke volume is 2000cc and 4cylinders Mechanical compression ratio is 12 of gasoline engine. Our country, Atmosphere-temperature change is -20℃, Compression ratio is 13.738 and thermal efficiency is 64.93%. Atmosphere-temperature 40℃, Compression ratio is 11.269 and thermal efficiency is 62.038%. The Compression ratio and thermal efficiency are increase to the low temperature. The results are as follows, 1. Atmosphere-temperature is change the intake air mass and air mass change is change the compression ratio in gasoline engine. 2. Compression ratio change is change the thermal efficiency and power to the gasoline engine. 3. For increasing the thermal efficiency and power, Air temperature be come down for more intake air in gasoline engine. 4. For come down intake air temperature in the stroke volume, intake manifold must be ahead of engine and exhaust manifold must be behind of engine.

교회공동체와 학교를 통한 청소년교육의 방법론 연구

성창환 서울장신대학교 출판부 2022 서울長神論壇 Vol.- No.30

The problem that the wave of modernization of Korean society has had on church education is very serious. one of the biggest reasons is the stubbornness of the conservative nature of the church orthodox faith according to change. in addition, the development of civilization that comes from social change makes all areas of life of church members flow to the material aspect rather than the pursuit of faith, which is the spiritual aspect. this is intensifying the problem of church education. and church education for adolescents was almost limited to Christian doctrine, creed, or recitation and delivery of church history. as a result, many teenagers attending church today have no choice but to wander due to their own concerns and conference conflicts without receiving specific guidance or education that can be a measure of ethical judgment amid rapidly changing social and cultural changes. Church education is Christian education, and the core of Christian education is faith. in the past and now, faith has been a firm purpose of education in church education. this is a part that most Christian educators acknowledge. in this respect, we know that the lack of faith is a problem in adolescents' lives and that it is urgent to lead them to more mature faith education. in addition, research on this is urgent as it has been found that even the direction of church education for youth guidance is shaking amid the rapidly changing social wave and confusion of youth values. the purpose of this study is to experience true faith by growing into a responsible being in community life as well as personal personality maturity of adolescents through efficient church education in rapidly changing times.

기후변화가 농업부문에 미치는 경제적 영향 분석

김창길(Chang-Gil Kim),이상민(Sang-Min Lee) 한국농업경제학회 2009 農業經濟硏究 Vol.50 No.2

This paper measures economic impact of climate change on crop farming in Korea. Using cross-sectional data on climate, soil, farmland prices, and other economic and geophysical data, we employ a Ricardian approach to measure the relationship between climate and the farmland value. The study carries out a marginal impact analysis of increasing temperature and changing precipitation. The empirical analysis reveals that a rise of 1℃ in the annual average temperature (12.4℃ ) brought down the price of farmland per ha by approximately KRW 14.5~19.2 million, equivalent to a 5.7~7.5% drop in the average farmland price. On the other hand, an increase of 1㎜ in the monthly average precipitation (110.8㎜) was estimated to increase the farmland price per ha by KRW 330~360 thousand. In general, the results show that the temperature component of global warming is much important than precipitation. Findings call for monitoring and early warn-ing system of climate change and dissemination of information to farmers to encourage adaptations to climate change.

Brain Topological Correlates of Motor Performance Changes After Repetitive Transcranial Magnetic Stimulation

Park, Chang-hyun,Chang, Won Hyuk,Yoo, Woo-Kyoung,Shin, Yong-Il,Kim, Sung Tae,Kim, Yun-Hee Mary Ann Liebert 2014 Brain connectivity Vol.4 No.4

<P>Repetitive transcranial magnetic stimulation (rTMS) influences the brain temporally beyond the stimulation period and spatially beyond the stimulation site. Application of rTMS over the primary motor cortex (M1) has been shown to lead to plastic changes in interregional connectivity over the motor system as well as alterations in motor performance. With a sequential combination of rTMS over the M1 and functional magnetic resonance imaging (fMRI), we sought changes in the topology of brain networks and specifically the association of brain topological changes with motor performance changes. In a sham-controlled parallel group experimental design, real or sham rTMS was administered to each of the 15 healthy subjects without prior motor-related dysfunctions, over the right M1 at a high frequency of 10 Hz. Before and after the intervention, fMRI data were acquired during a sequential finger motor task using the left, nondominant hand. Changes in the topology of brain networks were assessed in terms of global and local efficiency, which measures the efficiency in transporting information at global and local scales, respectively, provided by graph-theoretical analysis. Greater motor performance changes toward improvements after real rTMS were shown in individuals who exhibited more increases in global efficiency and more decreases in local efficiency. The enhancement of motor performance after rTMS is supposed to be associated with brain topological changes, such that global information exchange is facilitated, while local information exchange is restricted.</P>