• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제43권4호
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• pp.256-261
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• 2017

Objectives: The concept of natural head position (NHP) was first introduced by Broca in 1862, and was described as a person's stable physiologic position "when a man is standing and his visual axis is horizontal." NHP has been used routinely for clinical examination; however, a patient's head position is random during cone-beam computed tomography (CBCT) acquisition. To solve this problem, we developed an accelerometer to record patients' NHP and reproduce them for CBCT images. In this study, we also tested the accuracy and reproducibility of our accelerometer. Materials and Methods: A total of 15 subjects participated in this study. We invented an accelerometer that measured acceleration on three axes and that could record roll and pitch calculations. Recorded roll and pitch data for each NHP were applied to a reoriented virtual image using three-dimensional (3D) imaging software. The data between the 3D models and the clinical photos were statistically analyzed side by side. Paired t-tests were used to statistically analyze the measurements. Results: The average difference in the angles between the clinical photograph and the 3D model was $0.04^{\circ}$ for roll and $0.29^{\circ}$ for pitch. The paired t-tests for the roll data (P=0.781) and the pitch data (P=0.169) showed no significant difference between the clinical photographs and the 3D model (P>0.05). Conclusion: By overcoming the limitations of previous NHP-recording techniques, our new method can accurately record patient NHP in a time-efficient manner. Our method can also accurately transfer the NHP to a 3D virtual model.

• 전기전자학회논문지
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• 제12권4호
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• pp.185-195
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• 2008

본 논문에서는 PCS(Personal Communication System) 대역에서 동작하는 PIFA(Planar Inverted F Antenna)를 설계하여 특성을 살펴보았다. 설계된 PIFA를 폴더와 바, 슬라이드 타입의 단말기에 장착하여 성능을 확인하였다. 실제 사용자가 사용하는 상태와 가장 유사한 환경을 만들기 위해 헤드 팬텀과 핸드 팬텀을 추가하여 단말기 안테나의 성능에 미치는 영향을 분석하였다. 인체의 영향으로 인해 방사패턴이 크게 변형되는 모습을 보였으며, 안테나 효율 또한 현저히 저하되는 것을 전산 모의 실험을 통해 확인할 수 있었다. 단말기와 헤드 팬텀과의 위치 관계에 따른 변화를 확인하기 위해 단말기와 헤드 팬텀의 각도가 $0^{\circ}$일 경우를 기준으로 하여, $2^{\circ},\;4^{\circ}$로 변화시켜가며 단말기 안테나의 성능 변화를 살펴보았다. 그 결과 안테나가 헤드 팬텀에서 멀어질수록 지향성을 갖던 특성이 조금씩 줄어들면서 효율이 좋아지는 경향을 보였다. 다만 안테나의 위치가 상대적으로 헤드 팬텀에 가까운 바 타입의 경우, 이 같은 경향이 나타나지 않았다. 단말기의 형태도 성능에 큰 영향을 주는 것을 확인할 수 있었다.

• The Journal of Korean Physical Therapy
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• 제27권3호
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• pp.159-163
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• 2015

Purpose: This study aimed to determine the interaction among the neck, trunk, and lower extremities on the non-paretic side in head rotation along with non-paretic-side weight shifting of stroke patients. To compare stroke patients' ability to control posture through muscle activity variation related to pertubation during head rotation along with the non-paretic limb. Methods: We tested 15 hemiplegic patients and 15 normal individuals. Each group's muscle activity was measured by electromyography in neutral head position and head rotation position. We compared each group's resu lt based on measured values in patients' non-paretic neck muscles, trunk muscles, and lower limbs muscles activation. Results: The study showed that muscle activity increased in the sternocleidomastoid muscle (102.26%, 53.00%), splenius capitis muscle (97.93%, 54.93%), erector spinae muscle (241.00%, 127.60%), external oblique abdominal muscle (256.66%, 152.00%), and internal oblique abdominal muscle (252.80%, 152.6%), peroneus longus muscle (117.53%, 137.13%) and gastrocnemius muscle (119.06%, 137.20%), while the results for the sternocleidomastoid muscle, splenius capitis muscle, erector spinae muscle, external oblique abdominal muscle, internal oblique abdominal muscle, peroneus longus muscle, and gastrocnemius muscle showed a statistically significant difference (p<0.05). Conclusion: It is hard for stroke patients to engage in normal movement control under suggested conditions because of the insufficient movement against gravity on the stroke patient's non-paretic side and impaired cooperative patterns. To solve these problems, patients need their bodies to improve through effective movement, resulting in advanced control of their effective and functional activity.

• The Korean Journal of Physiology
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• 제19권2호
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• pp.139-153
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• 1985

기립 및 도립의 체위면화가 두부 및 하지의 혈액순환계에 미치는 영향을 관찰하고, atropine의 정주에 의한 부교감신경의 차단이 체위변화에 대한 심맥관계의 내성을 증가시키는 지를 보기위하여 개를 경사대에 수평위로 고정하여 수동적으로 기립 및 도립위로 체위를 변화시키고, 각 체위에서 10분간 유지시켜 경동맥, 외경정맥, 고동맥 및 고정맥의 분시 혈류량, 분시 심박수 및 분시 호흡수, 그리고 혈액의 pH, $PCO_2$, $PO_2$ 및 Hct를 측정하였다. 다시 수평위에서 atropine 0.5mg을 1회 정주한 후 위의 실험과정을 반복하여 시행하고 atropine투여전과 비교 관찰하였던 바 다음과 같은 결과를 얻었다. 기립시 두부 및 하지 동정맥혈의 분시 혈류량은 감소하였고, 특히 두부로 가는 혈류량의 감소가 더 컸으나, atropine의 투여는 경동맥의 분시 혈류량의 감소를 억제하였다. 도립시 두부 및 하지의 분시 혈류량은 유의한 변화를 보이지 않았고, 개체에 따라 변화양상도 다르게 나타났다. atropine의 투여는 투여전에 비하여 유의한 차이를 보이지 않았다. 분시 심박수는 기립 및 도립시 모두 증가하였다. atropine의 투여는 수평위에서 분시 심박수는 투여전 보다 증가하나, 체위변화에 의한 분시 심박수의 증가를 경감시켰다. 분시 호흡수는 개체에 따라 변화양상에 차이가 있으나, 대체로 기립시는 감소하고 도립시는 증가하였다. atropine의 투여는 기립 및 도립시 다 같이 분시 호흡수의 변화를 억제하였다. 혈액소견은 기립시 정맥철의 pH 및 $PO_2$는 감소하였고, $PCO_2$는 증가하나 동맥혈의 $PCO_2$는 감소하였다. 도립시 동정맥혈의 소견은 수평위에 비해 별 변화가 없었으며 , atropine의 투여후도 기립 및 도립시 모두에서 투여전에 비하러 유의한 변하는 없었다. Hct는 기립 및 도립시 증가하였으며 atropine투여에 의한 변화는 관찰할 수 없었다. 이상에서와 같이 atropine의 투여는 기립시 두부로 가는 혈류량을 증가시키며, 기립 및 도립시 발생할 수 있는 분시 심박수의 과도한 증가를 억제함으로서 체위변화에 대한 심맥관계의 내성을 증가시키는데 어느정도 효과가 있다고 하겠다.

• 한국농공학회지
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• 제41권5호
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• pp.77-85
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• 1999

Irrigation pipeline systems have been recently adopted for irrigation purposes, which was thought to improve irrigation efficiencies. However, if hydraulic characteristics are not evaluated in designing , overpressure due to waterhammer may occur and result in serious problems. Therefore, in this study a model was formulated to simulate unsteady motion of water in a pipeline resulting from valve closure, the applicability of the model owas tested with fiedld data, and the results showed good agreement in maximum piezometric head. Also, simulated maximum piezometric head was compared with designed piezometric head computed by empirical method, and maximum piezometric head in a pipeline resulting from valve closure was simulated and analyzed with varing surge tank's position and diameter.

• 한국농공학회논문집
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• 제56권6호
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• pp.1-9
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• 2014

In this study the pore water pressures were measured in sea dike constructed with the sand dredged in the sea, and they were analyzed with the hydraulic head loss rate to estimate quantitatively the state of blocking seepage in the sea dike embankment. Blocking state was expressed as the number between 0 and 1. the number of 1 means the state of perfectly blocking seepage and the number of 0 means the state of sea water being passing free. The deeper the installed position was the lower the hydraulic head loss rate was and the longer the seepage path length was the higher the hydraulic head loss rate was. The estimated R-squareds were close to 1, which means that the embankment was steady state without movement of soil particles.

• 대한두경부종양학회지
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• 제34권1호
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• pp.29-32
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• 2018

The parathyroid glands are usually located in the posterolateral area of the thyroid gland. Due to their embryologic origin, they are sometimes found in an ectopic position from the angle of the jaw to the mediastinum. However, their incidental detection in the hypopharyngeal wall is rare. Herein, we report a case of an ectopic parathyroid gland found in the hypopharyngeal wall of a 39-year old woman with no known endocrine abnormality.

• 한국응용곤충학회지
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• 제57권4호
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• pp.279-285
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• 2018

곤충 머리의 부분 명칭들과 동소이명(同所異名)인 suture들의 명칭을 구조의 부분별 위치와 기능을 기준으로 하여 정리하고 우리말 이름들을 체계적으로 모아서 조명하였다. 여기에는 머리 표면의 각종 선, 배자의 머리 구분, 머리의 외골격과 내골격, 입 내부구조, 긴주둥이, 더듬이 외부구조와 기본마디, 더듬이 모양, 표면 털 모양에 관한 용어들이 포함되어 있다.

• 치과방사선
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• 제19권1호
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• pp.25-29
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• 1989

The author has evaluated the panoramic image clarity of the midfacial anatomic structures in dry skull according to the skull position. The radiopaque markers were attached to the anatomic structures: infraorbial rim, upper and lower borders of zygomatic arch, pterygomaxillary fissure, lateral pterygoid plate, pyriform aperture of nasal cavity, lateral wall of maxilla, orbital floor, infraorbital foramen, and nasal floor. Position of the skull were divided into four groups. standard, 25mm forward, chin-down, chin-up position. The results were as follows: 1. The pyriform aperture of nasal cavity, lateral wall of the maxilla, orbital floor, infraorbital foramen and nasal floor did net cast any discernible image. 2. Nearly all images of midfacial structures were blurred in the chin-up position. 3. The forward position provided good visualization of the maxillary sinus. 4. The chin-down position provided good visualization of the zygomatic arch, pterygomaxillary fissue, and lateral pterygoid plate.

• The Korean Journal of Physiology
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• 제24권1호
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• pp.51-65
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• 1990

The purpose of the present study was to examine the hemodynamic responses, especially in arterial and skin blood flows, in conjunction with the changes of plasma catecholamine levels as an indirect marker of adrenergic tone during the early stage of head-down tilt (HDT), and to evaluate the early physiological regulatory mechanism in simulated weightlessness. Ten mongrel dogs, weighing8\;{\sim}\;14\;kg, were intravenously anesthetized with nembutal, and postural changes were performed by using the tilting table. The postural changes were performed in the following order: supine, prone, HDT $(-6^{\circ}C)$ and lastly recovery prone position. The duration of each position was 30 minutes. The measurements were made before, during and after each postural change. The arterial blood flow $({\.{Q}})$ at the left common carotid and right brachial arteries was measured by the electromagnetic flowmeter. Blood pressure (BP) was directly measured by pressure transducer in the left brachial artery. To evaluate the peripheral blood flow, skin blood flow $({\.{Q}})$ was calculated by the percent changes of photoelectric pulse amplitude on the forepaw, and skin temperature was recorded. The peripheral vascular resistance (PR) was calculated by dividing respective mean BP values by ${\.{Q}}$ of both sides of common carotid and brachial arteries. Heart rate (HR), respiratory rate (f) and PH, $Po_{2},\;Pco_{2}$ and hematocrit of arterial and venous blood were also measured. The concentration of plasma epinephrine and norepinephrine was measured by radioenzymatic method. The results are summarized as follows: Tilting to head-down position from prone position, HR was initially increased (p<0.05) and BP was not significantly changed. While ${\.{Q}}$ of the common carotid artery was decreased (p<0.05) and PR through the head was increased, ${\.{Q}}$ of the brachial artery was increased (p<0.05) and PR through forelimbs was decreased. ${\.{Q}}$ of the forepaw was initially increased (p<0.05) and then slightly decreased, on the whole revealing an increasing trend. Plasma norepinephrine was slightly decreased and the epinephrine was slightly increased. f was increased and arterial pH was increased (p<0.05). In conclusion, the central blood pooling during HDT shows an increased HR via Bainbridge reflex and an increased ${\.{Q}}$ of the forepaw and brachial ${\.{Q}}$, due to decreased PR which may be originated from the depressor reflex of cardiopulmonary baroreceptors. It is suggested that the blood flow to the brain was adequately regulated throughout HDT $(-6^{\circ}C)$ in spite of central blood pooling. And it is apparent that the changes of plasma norepinephrine level are inversely proportional to those of ${\.{Q}}$ of the forepaw, and the changes of epinephrine level are paralleled with those of the brachial ${\.{Q}}$.