• 대한인간공학회지
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• 제35권5호
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• pp.413-423
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• 2016

Objective:The aims of this study are to understand the effects of task (pushing, pulling, and clockwise and counter clockwise twisting) direction on the maximal output and their grip forces and to explore the relationship between the maximal output and the grip forces. Background: Knowing the normative maximal grip force is not enough to design a good hand tool. The industrial designers should understand the required grip forces in various motions toward a specific direction to make an effective and efficient hand tool. Method: Eighteen healthy volunteers participated in the series of isometric maximal output force tests. A custom-made force measuring equipment collected the output and the grip forces for three seconds. Force measurements along the vertical, coronal and sagittal axes were randomly repeated three times. Results: The pulling was strongest and the pushing was weakest in all directions. The effect of motion on the output forces varied in different directions. The corresponding grip force increased in the order of pushing, pulling, clockwise twisting, and counter clockwise twisting in all directions. The maximal output and their grip forces were highly correlated but the relationship was affected by motion and direction. The regression coefficient was greatest in pulling and smallest in clockwise twisting. Conclusion: The effect of motion on the output forces varied in different directions. The maximal output and their grip forces were correlated but the relationship was affected by motion and direction. Application: Findings of this study can be valuable information for industrial designers to develop more productive hand tools and work stations to help preventing the musculoskeletal disorders at work.

• 한국가시화정보학회지
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• 제11권1호
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• pp.28-33
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• 2013

This paper describes aerodynamic characteristics of an Archimedes spiral wind turbine with various angles of attack. The range of angles was controlled from $-30^{\circ}$ (clockwise) to $+30^{\circ}$ (clockwise). The rotating speed of wind turbine at the same angle of attack in both directions was different. The reason why the-maximum rotational speed was observed at $15^{\circ}$ in clockwise direction can be explained based on angular momentum conservation. Quantitative flow visualization around Archimedes wind turbine blade was carried out between $-15^{\circ}$ (clockwise) and $+15^{\circ}$ (counter clockwise) using high resolution PIV method. The relationship between drag force and rotating speeds was discussed. From these results, optimum design on yawing system of Archimedes spiral wind turbine may provide high efficiency on small wind power system.

• Bulletin of the Korean Chemical Society
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• 제23권12호
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• pp.1737-1743
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• 2002

We have studied the dynamics of energy-rich hydrogen molecules produced on a graphite surface through H(g) + H(ad)/C(gr) → $H_2$ + C(gr) at thermal conditions mimicking the interstellar medium using a classical trajectory procedure. The recombination reaction of gaseous H atom at 100 K and the adsorbed H atom on the interstellar graphite grains at 10 K efficiently takes place on a subpicosecond time scale with most of the reaction exothermicity depositing in the product vibration, which leads to a strong vibrational population inversion. The molecules produced in nearly end-on geometry where H(g) is positioned below H(ad) rotate clockwise and are more highly rotationally excited. but in low-lying vibrational levels. The rotational axis of most of the molecule rotating clockwise is tilted from the surface normal by more than 30°, the intensity peaking at 35°. The molecules produced when H(ad) is close to the surface rotate counter-clockwise and are weakly rotationally excited, but highly vibrationally excited. These molecules tend to align their rotational axes parallel to the surface. The number of molecules rotating clockwise is eight times larger than that rotating counter-clockwise.

• 대한인간공학회지
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• 제22권4호
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• pp.47-57
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• 2003

This study investigated the recruitment patterns of ten trunk muscles in isometric exertion tasks, focused on the functional roles (agonist or antagonist). Twelve male students performed maximum voluntary isometric exertion tasks towards six directions: flexion/extension, left/right lateral bending, and clockwise/counter-clockwise twisting. EMG signals from ten trunk muscles and exertion forces were collected. Normalized EMG (NEMG) values were calculated at 10, 20, 30, 40, 50, 60, 70, 80, and 90 %MVC. The subjects showed a limited capacity in producing twisting moments, approximately 50% of the extension moment, and 70% of lateral bending moments. EMG activity was dependent on the direction and magnitude of the exertion, and also on the functional role. The mean NEMG of agonist was 0.260 and 0.067 for antagonist. Agonists showed the highest mean NEMG in flexion (0.367), while antagonists showed the highest mean NEMG in twisting clockwise/counter-clockwise (0.090/0.106).

• 한국자기학회지
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• 제10권4호
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• pp.178-182
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• 2000

본연구에서는 서로 직교하는 yoke 장치와 4-채널 과도기록장치를 사용하여 회전하는 자기장을 발생시키고, 회전자화에 의한 자기적 손실을 측정할 수 있는 측정시스템을 구성하였다. 개발된 측정장치를 사용하여 무방향규소강의 회전자화에 의한 자기적특성을 측정하였으며, 회전자화에 의한 손실의 측정에서 자기유도성분의 측정방향과 자화력성분의 측정방향이 일치하지 않아, 시계방향 및 반시계방향으로 측정한 값이 차이를 나타내었다. 그러나 시계방향 및 반시계방향으로 측정한 회전자화에 의한 손실값의 평균은 일정함을 알 수 있었으며, 이를 이용할 경우 회전자화의 폭정오차를 줄일 수 있었다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제34권4호
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• pp.252-259
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• 2012

Purpose: This study evaluated the postoperative stability of counter clockwise rotation of the mandibular plane in anterior openbite patients, who have had one jaw surgery performed. Methods: This study includes patients with skeletal class III malocclusion accompanied by anterior openbite among the patients who have had BSSRO performed, resulting in counter clockwise rotation of the mandibule. We excluded the patients with genioplasty and segmental surgery, and included 23 patients who underwent BSSRO. Results: We found no statistical significance between the amount of counter clockwise rotation in the mandible in the Pearson correlation test. Also, there was no significant difference between Group 1 (< $3^{\circ}$) and Group 2 (> $3^{\circ}$). Conclusion: This study evaluated the amount of horizontal relapse, and the degree of relapse. Stable results were obtained. Although there was no statistical significance between the degree of openbite and the amount of horizontal relapse, the group with a greater amount of openbite had a greater amount of relapse.

• 한국운동역학회지
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• 제21권1호
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• pp.97-105
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• 2011

The purpose of this study was to investigate the kinetic factors of Stefan holm's take-off motion and provide the technical data. Collected data of the subject(height: 181 cm, weight: 71 kg, record: 230 cm) were used for the last two strides and take-off phase. The results were as follows: The vertical impulse force was 2044.8 N which was 2.49 times and the anterior-posterior impulse force was -1306.4 N which was 1.88 times of the subject's weight. The take-off leg angular velocities($\omega_x,\;\omega_y$) were switched drastically from clockwise to count clockwise direction between two-step touchdown and take-off. The highest jerk of the take-off foot was 368.97 m/s3 during the two step take-off and the take-off foot made an impact to the ground with 1225.07 m/s3 during the one step touchdown.

• 암석학회지
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• 제11권3_4호
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• pp.169-181
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• 2002

한반도 남동부의 울산단층 동편에는 염기성~중성 암맥군들이 우세하게 발달한다. 이 암맥들은 대부분 동해가 활발히 확장되었던 전기 마이오세(약 17 Ma 이전)의 지각 변형기 동안 동서방향의 지각 신장에 의해 만들어진 남북방향의 인장 균열을 통로로 관입하였다. 연일구조선을 경계로 서쪽지역과 인근지역 그리고 동쪽지역의 화강암체에서 관찰된 염기성 암맥의 평균 관입면 주향 방향은 동쪽으로 갈수록 시계방향으로 회전된다(N06$^{\circ}$E$\longrightarrow$N15$^{\circ}$E$\longrightarrow$N37$^{\circ}$E). 또한 연일구조선 동편의 염기성 암맥의 주향 방향은 동쪽 해안에 가까워질수록 시계방향으로 보다 많이 회전된 특징(구룡포반도에서 N75$^{\circ}$E)을 보여주었다 이는 이들 암맥들이 정치 이후 연일구조선 동쪽의 것들만 시계방향 수평 회전운동을 겪었으며, 이들 중 동쪽 해안에 가까운 것일수록 보다 많은 앙의 회전운동을 겪었음을 의미한다. 또한 동해의 확장으로 인해 대륙연변을 따라 발생한 북북서방향 우수향 전단력이 시간이 경과함에 따라 동에서 서로 전파되는 과정을 겪었으며, 연일구조선이 마이오세 분지 지역에서 흔히 관찰되는 지괴의 수평 회전운동을 규제한 주요 서쪽 한계선임을 지시하고 있다.

• 대한치과교정학회지
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• 제26권5호
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• pp.601-611
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• 1996

교정치료에 있어서 악안면 성장의 양상은 진단과 치료계획 수립에 있어서 매우 유용한 자료이며 교합의 달성 및 안모의 형태, 발육에 많은 영향을 미친다. 따라서 성장유형의 분류에 대한 많은 연구가 있었으며 성장예측을 위한 많은 시도가 있었다. 이에 본 연구에서는 성인 120명을 대상으로 치료전 측모두부계측 방사선사진을 이용하여 전안면고경에 대한 후안면고경의 비를 측정하여 $56\%-62\%$는 시계방향 성장군(36명), $65\%-80\%$는 반시계방향 성장군(43명)으로, 그리고 $62\%-65\%$는 정상군(41명)으로 분류하고 이에 따른 하악이부의 형태와 돌출정도 평가를 시행한 결과 다음과 같은 결과를 얻었다. 1. 남녀 하악이부 형태비교에 있어서는 남자가 여자보다 이부의 높이와 돌출정도가 크게 나타났다. 2. 시계방향 성장군이 반시계방향 성장군에 비해 하악이부의 Height, H/D ratio, Actual length는 크게 나타났고, Depth, Angle, effective length, E/A ratio는 작은 값을 나타냈다. 3. 악안면 성장양상에 있어 이부의 돌출정도가 작을수록 시계방향성장 경향을 나타내며, 돌출정도가 클수록 반시계방향성장 경향을 나타냈다.

• 수산해양기술연구
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• 제57권3호
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• pp.214-227
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• 2021

The distribution of tidal current and tidal induced residual current, topographical eddies and tidal residual circulation in the waters surrounding the Geumo Island-An Island channel were identified through numerical model experiments and vorticity balance analysis. Tidal current flows southwest at flood and northeast at ebb along the channel. The maximum flow velocity was about 100-150 cm/s in neap and spring tide. During the flood current in the neap tide, clockwise small eddies were formed in the waters west of Sobu Island and southwest of Daebu Island, and a more grown eddy was formed in the southern waters of Geumo Island in the spring tide. A small eddy that existed in the western waters of Chosam Island during the ebb in neap tide appeared to be a more grown topographical eddy in the northeastern waters of Chosam Island in spring tide. Tidal ellipses were generally reciprocating and were almost straight in the channel. These topographical eddies are made of vorticity caused by coastal friction when tidal flow passes through the channel. They gradually grow in size as they are transported and accumulated at the end of the channel. When the current becomes stronger, the topographic eddies move, settle, spread to the outer sea and grow as a counterclockwise or clockwise tidal residual circulation depending on the surrounding terrain. In the waters surrounding the channel, there were counterclockwise small tidal residual circulations in the central part of the channel, clockwise from the northeast end of the channel to northwest inner bay of An Island, and clockwise and counterclockwise between Daebu Island and An Island. The circulation flow rate was up to 20-30 cm/s. In the future, it is necessary to conduct an experimental study to understand the growth process of the tidal residual circulation in more detail due to the convergence and divergence of seawater around the channel.