도립(-6。)에 의한 심장혈관계 및 혈중 Catecholamine농도의 조기 변화

채의업,배재훈,현정애 啓明大學校 醫科大學 1991 계명의대학술지 Vol.10 No.1

Head-down tilt at -6℃ has been used as an experimuntal model to evaluate the effect on hemodynamics by movemunt of blood toward the central portion of the body under the conditions of weightlessness. So far there are a few disagreements between the findings reported by the different authors about early hemodynamic effects of heas-down tilt. Therefore, this study was done for the purpose to determine the early changes of hemodynamics and plasma catecholamine levels at head-down tilt from the prone position, which is more familiar than the supine position in the dog. Ten mongrel dogs weighing 8-12kg were anesthetized with the intravenous infusion of nembutal(30mg/kg), and the electromagnetic flow transducers were set up on the left common carotid and the right femoral artery to measure blood flow. Arterial pressure was measured directly by the strain gauge pressure transducer. Heart rate and respiratory rate, and pH, Po2, Pco2 and hematocrit of arterial and venous blood were also measured. The concentration of plasma epinephrine and norepinephrine was determined by Peuler and Johnson's radioenzymatic method. The postural changes were performe from the supine to the prone position, from the prone to the head-down position, and then to the prone position after head-down tilt and each posture was maintained for 30 minutes. The results are summarized as follows: When the posture was changed from the supine to the prone position, mean arterical pressure, heart rate, respiratory rate, blood flow of common carotid artery and plasma epinephrine level were increased, and blood, flow of femoral artery was decreased. Tilting to the head-down position from the prone position, arterial pressure was increased initially and maintained thereafter, and heart rate was slightly decreased and then gradually increased. Blood flow of common carotid artery was revealed a persistent increase, but that of femoral artery was not significantly changed. The change of carotid peripheral artery resistance was not significant, and femoral peripheral artery resistance was slightly increased, and respiratory rate was increased. At 30 minitues of head-down tilt, plasma norepinephrine level was slightly decreased and epinephrine level was increased. In the early phase of the recovery prone position after head-down tilt, arterial pressure and heart rate were significantly(p<0.01) increased comparing to the values at the end of the head-down tilt, and the higher arterial pressure was shown persistently during the recovery prone position. The changes of blood flow of common carotid artery and carotid peripheral artery resistance were not significant, but in the femoral artery, blood flow was decreased and femoral peripheral artery resistance was increased. Respiratory rate was not significantly changed. At 30 minutes of the recovery prone position after head-down tilt, plasma norepinephrine level was increased and plasma epinphrine level was significantly(p<0.05) increased comparing to the values at the end of head-down tilt. Through the periods of the serial postural changes, the changes of pH of arterial and venous blood were not significant, and gradual increase of Po2 and on the contrary gradual decrease of Pco2 wer revealed, their hematocrit were increased since 30 minutes of head-down tilt. In conclusion, when the posture is changed from the supine to the position, the heart rate is significantly increase and the other changes of cardiovascular systems are not significant. At the early stage of head-down tilt, the heart rate is transiently decreased and it is suggestive that cardiopulmonary baroreceptor is adequately operated according th the increased venous return from the lower body, however the arterial pressure and the blood flow of common carotid artery are increased thereafter. The significant rise of arterial perssure and heart rate in the recovery prone position after head-down tilt may be a result of the pressor reflex by the cardiopulmonary baroreceptor according to the diminution of a hydrostatic pressure produced by the head-down tilt, which is evidenced by an elevation of the plasma catecholamine levels.

ANALYZING PEDESTRIAN HEAD INJURY TO DESIGN PEDESTRIAN-FRIENDLY HOODS

T.-L. TENG,V.-L. NGO 한국자동차공학회 2011 International journal of automotive technology Vol.12 No.2

Head injuries are a major cause of fatalities in pedestrian-car accidents. The HIC (Head Injury Criterion) value, a measure of the fatality risk of a head injury, is calculated from the acceleration of the head’s center of gravity (henceforth, head center) resulting from a head impact. The pedestrian’s head does not impact the hood at a direction normal to the hood’s surface. The direction of motion of the head center may change extremely rapidly upon impact, and normal acceleration may also significantly contribute to the resultant acceleration of the head center. Therefore, pedestrian head protection studies should consider how normal acceleration contributes to the resultant acceleration of the head center. It is necessary to control the resultant acceleration of the head center to produce an optimal characteristic pulse. This study analyzes the composition and variations of the head’s acceleration in head-to-hood impacts, focusing on exactly how the normal and tangential components of the acceleration contribute to the resultant acceleration of the head center. This study also considers how structural design parameters affect each component of the resultant acceleration. Methods to control the resultant acceleration of the head center to produce an optimal characteristic pulse can be proposed based on the results of this study. The analytical models and the results of this study contribute to efforts to design vehicle hoods and pave the way for developing pedestrian protection technologies.

한국어에 존재하는선핵적(head-initial) 구성

김미주 한국언어학회 2024 언어 Vol.49 No.2

This paper identifies the presence of head-initialconstructions in Korean language and examines their typological implications. Despite Korean's classification as an OV-ordered language, which typicallyimplies a strict head-final order with the dependent following the head, empiricalevidence presented herein challenges this expectation by unveiling instances ofhead-initial constructions across NP and clausal levels. These constructionsexhibit distinct semantic interpretations compared to their head-finalcounterparts. Drawing upon Dryer's(2007) discourse concerning thecross-linguistic correlations between word order characteristics and therelationship between head and dependent, the paper examines the implicationsof head-initial constructions in Korean. Since certain orders, such as thoseobserved between nouns and numerals/relative clauses, demonstrate lowcorrelations with the head-dependent order, the occurrence of head-initialconstructions in OV-languages does not represent an anomalous linguisticphenomenon. However, the order between verbs and objects demonstrates astrong correlations with the head-dependent order, necessitating a reevaluationof grammatical discussions when head-initial constructions coexist withhead-final constructions in OV-languages. Furthermore, this paper speculateson geographical, historical, communicative, and cognitive factors contributing tothe emergence of head-initial constructions. It is anticipated that thesedeliberations will enrich the understanding of syntactic variations in Koreanlanguage and underscore its position within typological discussions concerningsyntactic flexibility and related phenomena.

두부외상환자에서의 예후인자

최성혁,문준동,김수진,문철규,이성우,홍윤식 대한응급의학회 2001 대한응급의학회지 Vol.12 No.2

Background: Predicting outcome after head trauma is of great interest for clinicians, especially in the early stage. It may provide a basis for therapeutic strategies and may be helpful to select different approaches. But, reliable outcome prediction from head trauma is still unresolved. The purpose of this study is to determine which clinical parameters can be used effectively after an event of head trauma. Methods: In our study we studied head trauma patients who came to the Emergency department of Korea University Medical School Anam Hospital from the 1st of June 1998 to 31th of January 2000, looked into medical records, and studied the records in a retrospective manner. The head trauma patients were divied into two group, a) favourable outcome-related and b) unfavourable outcome-related. The two groups were then subdivided according to their sex, age, the mechanism of their injury, the time they came in, alcohol drinking, loss of consciousness, vomiting, pupil change, previous medical illness, associated injuries and were seperately compared and analyzed. And the factors affecting Glasgow Outcome Scale(GOS) were analyzed in the parameters of Injury Severity Score(ISS), Revised Trauma Score(RTS), Glasgow Coma Scale(GCS), motor score of GCS(mGCS), Marshall Computed Tomographic Classification(MCTC). Statistically, t-test and Mann-Whistney rank sum test using Jandel-sigma were used in the study and then were assessed in Chi-square analysis methods. The statistical significance was determined at a level of p less than 0.05. Results: The total of the head trauma patients, added up to 129 people, 99:males and 30:females. Among this sum, 99 patients showed a favourable outcome and 30 patients showed an unfavourable outcome at discharge. The causes of injury included: automobile accident in 42 cases; fallss in 26; assaults in 6; and accidental-slipping injury etc in 55 cases. 12 patients had bilateral unreactive pupils on admission, 2 had unilateral reactive pupils, and 113 had bilateral reactive pupils. Compared to the favourable outcome-related head trauma group, the unfavourable outcome-relared head trauma group had more history of loss of consciousness, unreactive pupils and tended to have previous medical illness. There were no difference in alcohol related, vomiting and associated injuries between two groups(favourable outcome-related head trauma group: unfavourable outcome-related head trauma group). Substantial difference were observed in GCS, mGCS, ISS, RTS, MCTC between two groups. Patients with unfavourable outcome had a significantly higher ISS, lower RTS, lower mGCS. After MCTC, patients with mass lesion had unfavourable outcome than patients with diffuse injury. Conclusion: Age, history of loss of consciousness, previous medical illness and unreactive pupil change are predictives of outcomes of head trauma patients with respect to Glasgow outcome scale. The lower GCS, lower RTS, lower mGCS, higher ISS, mass lesion based on CT scan provide poorer prognostic outcome in patients with head trauma. Use of prognostic factors thorough complete history taking and physical examination would provide useful prognostic information and facilitate improved therapeutic decision-malting in head-injuried patients.

경직형 양하지 마비 아동의 보행시 머리 안정성의 역할

김태우 ( Tae Woo Kim ),서혜정(교신저자) ( Hye Jung Seo ),이명진 ( Myung Jin Lee ),오태영 ( Tae Young Oh ) 대한신경치료학회 2011 신경치료 Vol.15 No.1

Purpose The purpose of this study was to compare movement of head, trunk and pelvis and to anJysis of correlation with COG during walking between normal and spastic diplegia children. Method Ten children with spastic diplegia who could walk independently and io normally developing children were enrolled. Gait analysis were accompanied all of participants. We assessed the statistical relationship among the data of joints, such as the head, trunk and pelvis using Qualisys motion analysis. Result The findings of this study were as follows: First, there was no significant difference on all movements of head-chest between normal and spastic diplegis, but there were significant differences on ML(mediolateral) & vertical movements of head-pelvis and mediolateral movements of chest-pelvis. Second, we did find the correlation between AP(anteriolateral) movements of head-chest and head-pelvis, between AP movements of head-pelvis and ML movements of head-pelvis & chest-pelvis, between ML movements of head-pelvis and ML movements of chest-pelvis & vertical movements of head-pelvis, and between vertical movements of head-chest & head-pelvis. Third, we did find the positive correlations between vertical change of COG and ML movement of head-chest, and between vertical change of COG and vertical movements of head-pelvis during walking. Conclusion This study showed that ML & vertical movements of head-pelvis and ML movements of chest-pelvis in spastic diplegia children were more increased than normal children; therefore, head stability is an improtant role for increasing gait pattern in spastic diplegia.

The Resetting of the Head Direction Parameter

Mi-kyung Shin 서울대학교 외국어교육연구소 2015 외국어교육연구 Vol.18 No.-

This study aims to investigate the availability of the head direction parameter to Korean learners of English to find out how learners learn the head direction of English phrases in the EFL classroom. 95 intermediate and beginner students in their first year of middle school in Korea completed production and comprehension tasks. The results showed that the head final strategy is used more often than other interlanguage strategies when the head initial strategy is not available, which tends to show that the head parameter is reset through L1 values. In addition, the production task also proved that the acquisition of the VP head direction is accompanied by the acquisition of the NP, PP and AP head directions. In contrast, the participants showed a strong tendency of applying the head final strategy in translating English sentences in comprehension tasks. One possible explanation for this discrepancy between the production and comprehension tasks is that the interference of the Korean head final structure lets students decide the noun before the head is the compliment of the head. The pedagogical implication drawn from this study is that the head direction should be taught to beginners particularly in communicative classrooms

Modeling of Dual Head Gantry Radiotherapy System with Monte Carlo Simulation

Seungwoo Park(박승우) 대한방사선과학회(구 대한방사선기술학회) 2017 방사선기술과학 Vol.40 No.4

듀얼 헤드 갠트리(dual-head) 갠트리 방사선치료 시스템을 설계하기 위해 LINAC의 단일 헤드는 GATE를 예비 연구로 사용하여 모델링되었다. LINAC 헤드는 임상에서 사용되고 있는 VARIAN사를 대상으로 모델링되었다. LINAC 헤드에서 생성된 6MV의 광자선을 물 팬텀에 조사하여 빔의 특성을 평가하였다. GATE 시뮬레 이션은 X- 선 스펙트럼을 생성한 후 물 팬텀에 광자선을 조사하였다. 결과로는 백분율 깊이 선량 과 빔의 프 로파일을 평가하였으며, 5 × 5와 10 × 10 ㎠에서 수행하였다. 빔 품질이 검증 된 후 듀얼 헤드 갠트리(dual head gantry) 방사선치료 시스템을 시뮬레이션 한 후 팬텀(phantom)을 이용한 선량 분포 측면에서 LINAC 시 스템의 단일 헤드와 비교하였다. 듀얼 헤드 갠트리 방사선치료 시스템은 단일 헤드 방사선치료 시스템에 비 해 방사선치료의 효율 면에서 40~60% 높은 것을 확인할 수 있었으며, 듀얼 헤드 방사선치료 시스템은 방사선치료 및 치료시간을 줄일 수 있을 것이 사료된다. In order to design a dual-head gantry radiotherapy system, the single head of LINAC was modeled using GATE as a preliminary study. The LINAC head was designed with VARIAN manufacturer’s information. 6 MV photons were generated from the head and the photons w irradiated to a water phantom for beam evaluation. GATE simulation was segmented by two stages, the one was to generate X-ray spectrum and the other one was for irradiation X-ray to the water phantom. The quantitative results were described in Percentage depth dose and beam profile. Two field size conditions were employed as 5 × 5 and 10 × 10 ㎠. After beam quality was verified, dual heads gantry radiotherapy system were simulated and they was compared to the single head of LINAC system in terms of dose deposition with in the phantom. The simulated LINAC head showed accept-able beam quality result for radiotherapy. The efficiency was calculated that deposited dose from dual heads was divided by the dose from single head. At all conditions, dual heads showed higher treatment efficiency. Efficiency was increased about 40 to 60%. Form the result, The dual head gantry system of new LINAC system will contribute to the practical radiotherapy of tumor and to reduce treatment time.

스프링클러 헤드의 방수상수에 따른 소화성능에 관한 실험적 연구

허민녕,신창섭,Hur, Min Noung,Shin, Chang Sub 한국안전학회 2018 한국안전학회지 Vol.33 No.2

The sprinkler system is a basic fire extinguishing system widely used, but there is a lack of quantitative assessment of its performance. In this study, to evaluate the fire extinguishing performance of the sprinkler head according to the discharge coefficients, experiments were conducted. Experimental sprinkler heads were selected with heads having K50, K80 and K115 water discharge coefficients, and the fire source was assumed to be an indoor fire in Class A Model 1. As experimental results, the time required for the fire chamber to cool down to $200^{\circ}C$ was 26 seconds for the K115 head, 414 seconds for the K80 head, and 481 seconds for the K50 head, so the cooling time of the K115 head was decreased by 94.5% compared to K50 head. In the case of restoring the oxygen concentration to 15%, the K115 head did not decrease below the oxygen concentration of 15%, and the K80 head took 145 seconds and the K50 head took 484 seconds. The lowest oxygen concentration in the fire chamber was 16.1% for the K115 head, 14.33% for the K80 head, and 11.28% for the K50 head, indicating that the K115 head was superior to the K80 and K50 heads by 13.1% and 43.7%, respectively. As the experimental results show, there is big difference in the extinguishing performance depending on the discharge coefficients of the sprinkler head. Therefore, in designing the sprinkler system, the discharge coefficients of the sprinkler head should be selected considering the heat release rate at the installation site and the fire extinguishing characteristics of sprinkler head.

서베일런스 시스템에서 HMM을 이용한 실시간 헤드 움직임 검출

박양재 한국정보기술학회 2014 한국정보기술학회논문지 Vol. No.

This paper addresses a technique of detecting a head nod and shake. The proposed system is composed of head tracking and head motion decision. The head tracking step is divided into head detection, head location. We propose a method of fast frontal head detection method. We use motion segmentation algorithm that makes use of differencing to detect moving people’s head. The novelty of this paper comes from the differencing in real time input images, preprocessing to remove noises (morphological operator and so on), detecting edge lines and restoration, finding the head area and cutting the head candidate. It is performed at the region close to a pair of heads for real-time head tracking. After head tracking, the coordinates of the detected head are transformed into the normalized vector of the x-coordinate and the y-coordinate. Head nod and shake detector using three HMMs. Head nod and shake can be detected by three HMMs those are adapted by a directional vector. The directional vector represents the direction of head movement. The vector is HMMs to determine neutral as well as head nod and head shake. Experimental results show a higher degree of 5% than the conventional method proposed a method of recognition performance. 본 논문은 머리의 끄덕임과 흔들림의 탐지 기술에 대하여 설명한다. 제안하는 시스템은 머리 움직임의 추적으로 구성되며 머리를 탐지하기 위하여 차영상 방법을 이용하는 움직임 구역화 알고리즘을 사용한다. 제안하는 방법의 실효성은 실시간 입력 영상에서 차영상을 이용하는 것과 잡음 영상을 제거(모폴로지 연산 등)하기 위한 전처리 과정과 윤곽선의 탐지와 복원, 머리 영역의 탐지와 머리 후보의 획득 과정이다. 머리의 끄덕임과 움직임을 탐지하기 위하여 세가지 HMM을 이용한다. 머리 끄덕임과 움직임은 방향 벡터에 의하여 조정 되어진 세 가지 HMM에 의하여 탐지될 수 있다. 그 벡터는 머리 끄덕임과 움직임뿐만 아니라 고정을 결정하는 HMM 이다. 실험 결과에서 보면 제안하는 방법으로써 머리의 움직임을 탐지하였을 때 기존의 방법보다 5% 정도 더 높은 인식 성능을 보여준다.

골프 스윙 시 선수와 비선수의 두부 분절 움직임 패턴 비교: 골프 헤드업에 관한 해석

손지훈 ( Sohn Jee-hoon ),구도훈 ( Koo Do-hoon ) 한국융합과학회 2022 한국융합과학회지 Vol.11 No.8

연구목적 본 연구는 골프 샷의 명언 중 하나인 'Do not head up'에 대한 운동학적 분석을 수행하고 그것을 해석하는 것에 목적이 있다. 연구방법 엘리트 골프 선수 8명과 비선수 10명의 5번 아이언 샷을 측정한 뒤, 스윙 구간 전체에서 머리 움직임 변화를 분석하였다. 스윙 구간은 어드레스(AD), 미들 오브 백스윙(MBS), 백스윙 탑(BST), 미들 오브 다운스윙(MDS), 임팩트(IMP), 미들 오브 폴로스루(MF)로 구분하였다. 적외선 기반 3차원 동작분석 시스템을 사용하였다. 머리 분절 좌우 관자놀이에 부착한 2개의 적외선 반사 마커 중심을 머리의 움직임으로 정의하였다. 골프 스윙 시 정의된 머리 분절의 3차원적 움직임을 집단 간 비교하였다. 결과 선수의 경우 머리의 움직임이 백스윙 시 우측(-y 축 방향), 하방(-z 축 방향)으로 움직임이 나타나고, 다운스윙 시 좌측(+y 축 방향), 후방(-x 축 방향), 하방(-z 축 방향) 의 방향으로 3차원 공간에서 머리 움직임이 나타났다. 비선수들은 백스윙 시 이미 머리 위치가 높아지면서 임팩트 시 머리 위치가 충분히 내려오지 못하는 패턴을 보였다. 선수들은 다운스윙 시 일관된 머리 움직임이 타나났으나, 비선수의 경우는 피험자 간 각기 다른 패턴의 머리 움직임을 보였다. 결론 골프 코칭 시 '머리를 들지 마라라는 격언으로는 부족하다. 골프 스윙 동작 시 머리 움직임의 3차원적 피드백이 제공되어야 올바른 머리 움직임을 바탕으로 골프 스윙이 이루어질 수 있을 것이다. Purpose The purpose of this study is to analyze the head movements of elite golfers and non-players during golf swings to interpret the meaning of head-ups kinematically. Method After measuring the 5th iron shot of 8 elite golfers and 10 non-players, the change in head movement was analyzed throughout the swing section. Swing sections were divided into address (AD), middle of back swing (MBS), back swing top (BST), middle of down swing (MDS), impact (IMP), and middle of through (MF). An infrared-based three-dimensional motion analysis system was used. The center of the two infrared reflective markers attached to the left and right temples of the head segment was defined as the movement of the head. The three-dimensional movements of the head segment defined during the golf swing were compared between groups. Result In the case of the eltie golfers, the movement of the head appeared in the right(-y axis direction) and downward directions(-z axis direction) during the backswing, and the movement of the head appeared in the three-dimensional space to the left(+y axis direction), post direction(-x axis direction), and downward(-z axis direction) directions during the downswing. Non-elite golfers showed a pattern in which the head position was not sufficiently lowered during impact as the head position was because of already increased haead position during the backswing. The elite golfers showed consistent head movements during downswing, but in the case of non-athletes, they showed different head movements between subjects. Conclusion When coaching golf, the adage Do not head up is not enough. In the case of a golf swing motion, three-dimensional feedback of the head movement might be provided so that the golf swing can be achieved based on the correct head movement.