• 한국표면공학회지
• /
• 제10권3호
• /
• pp.3-11
• /
• 1977

3가크롬 鍍金法은 6가크롬 鍍金法의 諸 欠点을 克服할 수 있다는 事실이 알려져 外國에서는 오래 前 부터 工業的 실用化를 위한 硏究가 活潑하게 行하여 졌고, 이중 최근에 發表된 Alecra 3 process는 電着諸特性이 뛰어난 方法으로 裝飾크롬 鍍金 分野에 利用되고 있다고 한다. 本 硏究는 Alecra 3 process의 浴 組成中 개미산칼륨으로, 염화칼륨을 염화나트륨으로 大替한 浴의 電着諸特性을 調査하고 最適 염化크롬의 濃度와 錯化比를 함께 調査하여 다음과 간은 結果를 얻었다. (1) 外觀, 被覆性,均一電着性 및 平均 電析 速度 등은 염화크롬 濃度가 0.4 mol일때 가장 良好하였다. (2) 개미산나트륨 대 염화크롬의 mol比는 염화크롬이 0.4 mol일때 2~3이 比較的 良好한 電着諸特性을 보여 주었다. (3) 개미산나트륨 및 염화나트륨 含有한 鍍金浴의 電着諸特性은 Alecra 3 Process의 特性과 비슷하였다.

• 대한정형외과스포츠의학회지
• /
• 제9권1호
• /
• pp.65-68
• /
• 2010

15세 씨름선수에서 발생한 주두의 횡상 골절 1례에서 골이식 및 내고정 치료를 시행 후, 술 후 6주에 골유합 소견을 확인하고 능동적 근력강화 운동을 통하여 술 후 6개월에 기존 강도의 운동으로 복귀하였다. 18세 야구선수에서 발생한 주두의 사선상골절 1례에 대해서는 안정 및 근력강화운동을 통한 보존적 치료를 시행하였으며, 3개월 후 통증이 완화되어 투구 운동을 재개하였고, 6개월 후 기존 강도의 운동으로 복귀하였다.

• 수산해양교육연구
• /
• 제17권1호
• /
• pp.35-47
• /
• 2005

The purpose of this study is to investigate various kinds of discipline problems in middle school classrooms, and the differences in severity and frequency of the classroom discipline problems between male and female students' classrooms in middle schools. This study shows that the discipline problems in the middle school classrooms include using a cellular phone, chattering, sleeping, chewing gum, reading comic books, asking useless questions, challenging a teacher, fighting, calling names, skipping class, throwing trash in the classroom, breaking classroom equipment, creating disorder, losing materials, playing with a ball in the classroom, gambling, and so on. Generally, male students recognized the severity of the classroom discipline problems more than the female students. However, it is shown that the frequency of discipline problems in male students' classrooms is higher than that in female students' classrooms. From the results of this study, male students have more active discipline problems (playing with a ball in the classroom, throwing trash in the classroom, coming to class late, gambling, cutting in line, and so on). On the other hand, female students have more passive discipline problems (making a noise by using a cellular phone, asking useless questions, sending messages to a classmate, studying other subjects, scattering, and so on).

• 대한정형외과스포츠의학회지
• /
• 제4권2호
• /
• pp.95-99
• /
• 2005

견봉쇄골관절의 손상은 대개 견관절에 직접 가해지거나 상완을 통해 간접적으로 전해지는 충격으로 인해 발생하게 되지만, 투구활동을 하는 운동선수의 경우 과 사용으로 인한 반복적인 자극이 손상을 유발할 수 있다. 견봉쇄골관절의 안정성에 관계된 인대의 손상 정도에 따라 견봉쇄골관절 손상의 방향과 정도가 결정된다. 따라서 견봉쇄골관절의 해부와 손상기전에 대한 이해를 바탕으로 한 정확한 분류를 통해, 투구 활동과 관계된 견봉쇄골관절 손상에 대한 적절한 치료 방침을 세울 수 있다.

• 한국운동역학회지
• /
• 제22권1호
• /
• pp.1-7
• /
• 2012

The purpose of this study was to investigate the pattern change of throwing in baseball after 15 weeks of participation in baseball class, by examining ball speed, trunk and upper body angles. The comparison was with 6 university students that haven't had any experience in baseball. 8 infra red cameras and 2 force platforms were used to collect the data. First, there was an increase in the speed of the ball after the class. Second, there was no significant difference in the allocated phases during the throw before and after class. Third, the release point was lower and more in front. Forth, there was an increase in the knee flexion at the left foot landing and release point. Finally, there was an increase in the maximum shoulder external rotation and pelvis angle. It is recommended that the coordination between the segments should be investigated to improve our understanding of the learning of throwing in future research.

• 한국농업기계학회:학술대회논문집
• /
• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
• /
• pp.458-468
• /
• 1996

The Oil Palm industry has developed tremendously with the increasing of planted area from 54,000 hectaresin 1960 to about 2.28 million hectares in 1995. This is expected to increase further to 2.5 million hectares by the year 2000. However, there has been an increasing difficulty in obtaining sufficient labour for the oil palm plantations. At present , harvesting of oil palm fresh fruit is facing an acute shortage of workforce as the workers are much more attracted to the better working environment and salary in the industrial sector. Harvesting of short palm is easily done by using a chisel attached to a short steel pole. Cutting is done by moving the tool at high speed to the target. The weight of the tool coupled with the speed of throwing will produce enough energy to cut the bunch stalk. In this cutting method, sharpness of the cutting device, weight of tool and the speed of throwing contribute to the efficiency of the tool . For the tall palms, a sickle attached to a ong pole is used and the job is more difficult compared to the short palms. Lifting of pole and cutting jobs require great effort and skills. This paper describes the basic design needs in developing an appropriate device that is practical for field use. A prototype design was developed and tested.

• Journal of Biosystems Engineering
• /
• 제43권3호
• /
• pp.194-201
• /
• 2018

Purpose: The objective of this study was to propose a formula for the theoretical grain mean transport velocities of an elliptically moving oscillator by modifying the grain mean transport velocity formula applied to linear motion and to compare the calculated values with the experimental values of grain mean transport velocity. Methods: The values of the throwing index ($K_v$) and the maximum horizontal velocities for various positions on the elliptical oscillator were obtained using kinematic analysis. To obtain the actual grain transport velocity, the mean transport velocities of perilla grains at six positions on the sieve surface were measured using a high-speed camera and compared with the theoretical values. The cam with an eccentric bearing on the oscillator was designed to be eccentric by 1.6 cm so that the lengths of the major axis of the elliptical motion were 3.2-3.6 cm. The material used in the experiments was perilla grain. Results: The experimental result was consistent with the theoretical value calculated using the proposed formula ($R^2$ is 0.80). It is considered that the angle difference between the maximum accelerations in the directions vertical and horizontal to the sieve has as much influence on the grain mean transport velocity as the value of Kv itself. Conclusions: It was possible to theoretically obtain the grain mean transport velocities through a screening device in elliptical motion by modifying the formula of the grain mean transport velocities used in linear motion.

• 한국운동역학회지
• /
• 제20권4호
• /
• pp.457-467
• /
• 2010

This study intends to analyze the projection factors' difference on each record of women's javelin throwing. For this purpose, the research analyzed the best record and the lowest one of athletes in top 1~7 ranks respectively, who participated in 2009 Daegu Pre-Championship Meeting. For analyze kinematic factors, we analyzed their game photos mainly shot by 3 cameras installed in side places. The used analysis program was Kwon3D 3.1. Analysis variables were the projection velocity, angle, height, trunk lean angle, and supporting leg's knee angle. The results concluded as follows: Different record showed statistically significant differences(p<.05) in terms of horizontal velocity and resultant velocity. There were no statistically significant differences in the variables of projection angle, its height, trunk lean angle and knee angle of support leg. But for the analyzed results to each individual characteristics, the horizontal velocity, projection height, knee angle of support leg and trunk lean angle of release event appeared to have influence on record.

• 열처리공학회지
• /
• 제7권2호
• /
• pp.129-138
• /
• 1994

The purpose of this study is to clarify the influence of the reaction temperature and $AlCl_3$ content on the aluminide coating formation on Ni-based superalloy IN713C in CVD process and to compare its throwing power with that of Pack Cementation process. Aluminide coating was formed by CVD in hot-wall stainless tube reactor from an $AlCl_3-H_2$ mixture in the temperature range $850{\sim}1050^{\circ}C$. At reaction temperature $850^{\circ}C$, the coating thickness and the content of aluminium at the surface were increased as $AlCl_3$ heating temperature was raised. At reaction temperature $1050^{\circ}C$, they were not influenced by the variation of $AlCl_3$ heating temperature. When $AlCl_3$ heating temperature was fixed $125^{\circ}C$, the phases of the coatings were varied from $Ni_2Al_3$ to Al-rich NiAl and to Ni-rich NiAl with the reaction temperature. Therefore, in this study the reaction temperature has been found to be a major factor in determining the phase formed in CVD process. The throwing power of CVD was superior to that of Pack Cementation.

• Corrosion Science and Technology
• /
• 제17권6호
• /
• pp.272-278
• /
• 2018

Reinforced concrete (RC) has been used as a construction material in various environments, such as airports, bridges, and ocean concrete structures, etc. Over time, however, rebar in the concrete is prone to corrosion from environmental forces and structural defects of the concrete. Cathodic protection (CP) was invented to prevent problems with corrosion and is widely used for different applications. Cathodic protection is divided into two types: sacrificial anode cathodic protection (SACP) and impressed current cathodic protection (ICCP). There are several limitations to the use of sacrificial anode cathodic protection in complex reinforced concrete structures, including concrete resistivity, throwing power of the CP, and environmental conditions. These limitations can affect the protection performance of SACP. Therefore, we used impressed current cathodic protection in our study. We tested Ti-Mesh, Ti-Rod, and Ti-Ribbon anodes in slab type reinforced concrete specimens. Electrochemical tests were conducted to confirm the impressed current cathodic protection performance under different environmental conditions.