• 대한가정학회지
• /
• 제49권2호
• /
• pp.63-74
• /
• 2011

Tension and self-control are explanatory factors in adolescent delinquency, and internet addiction and anonymity are regarded as factors underlying cyber deviation. The aim of this study was to investigate the interrelationships between these factors and cyber deviation. Participants were 485 middle and high school students in the Jeonbuk region. The results showed that tension and self-control were predictors of cyber deviation and that internet addiction was a mediating variable for both the predictors. Anonymity was found to have a mediating role, but only in respect of the tension-cyber deviation pathway. These findings suggested a number of implications. Firstly, the educational programs on cyber deviation should be different from the existing deviation prevention programs. Secondly, measures to prevent internet addiction are needed for the effective prevention of cyber deviation. Lastly, the finding of a relationship between anonymity and cyber deviation indicates the need to adopt a long-term perspective drawing on values education techniques to develop a code of cyber space ethics for "netizens".

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 1999년도 제3회 압연심포지엄 논문집 압연기술의 미래개척 (Exploitation of Future Rolling Technologies)
• /
• pp.423-428
• /
• 1999

A high precision hot strip width control method has been developed in this study by applying interstand looper tension measuring system at finishing mill stands. As with deviation of hot rolled steel strip is closely related to abnormal increase in the interstand strip tension, on-line measuring device of looped tension and data analyzing system was developed in this study. To determine dominant factors that will cause local width shortage, the logged data sets of bar width, bar thickness, looper tension, and strip thickness along the strip length were correlated with the data set of strip width change. With the result of the correlation analysis, existing sequence control logic and parameters for looper actuator were modified for strip width quality and the gains of the looper control were refined for the stable operation during the full passage of rolled strip. The on-line tension measurement and tension feedback control for looper system improved strip travelling stability and reduced strip width deviation in the srip top end region.

• 국제물리치료학회지
• /
• 제3권2호
• /
• pp.475-478
• /
• 2012

The purpose of this study is to identify the level of masseter muscle tension according to the levels of restricted movement and pain in the temporomandibular joint(TMJ), thereby verifying the fact that excessive masseter muscle tension can be a cause for restricted movement and pain in the TMJ. The subjects of this study were 81 men and women in their 20s and 30s, who feel uncomfortable with their masticatory function on the preferred chewing side. The subjects were measured in terms of the range of motion (ROM) and deviation of the TMJ and the degree of pain in the affected region. The ROM and deviation of the TMJ were measured using the Global Posture System(GPS) after instructing each subject to open his/her mouth to the fullest and taking photos of the subject with a digital camera. The tension of the masseter muscle was measured with a Pressure Threshold Meter(PTM). After the measurements, in order to compare the ROM of the TMJ, the subjects were divided into two groups based on the ROM of above 35mm and below 35mm. For the deviation and pain, based on the average of total subjects, the subjects were divided into two groups of above and below average. Thereafter, the levels of masseter muscle tension were compared between each pair of groups. According to the results, when each variable was compared between the respective two groups, in terms of the deviation, the pressure pain threshold(PPT) of the masseter muscle revealed a statistically significant difference(p<.05). However, the ROM and pain showed no statistically significant difference. Consequently, masseter muscle tension may cause restricted movement in the TMJ. In particular, the deviation and tension in the masseter muscle is considered to be a factor that causes deviation in the TMJ.

• 제어로봇시스템학회논문지
• /
• 제16권10호
• /
• pp.1006-1012
• /
• 2010

The hot rolling process ranks the highest position for production in steel making process. The hot strip manufacturing processes consist of the reheating furnace, roughing and finishing mill and coiler. The reheating furnace heats the slab. The roughing and finishing mill produce the hot strip from slab. The hot strip quality mainly depends on finishing mill, which consists of 4-high 7 stands. The looper is installed between stands and is used for controlling the strip tension by the looper angle for better material flow. It is difficult to control the strip tension with the coupled looper system from interaction between the looper angle and strip tension. Too much deviation of strip tension severely affects the poor width quality of the hot strip. It is important to control simultaneously both the looper angle and strip tension with each of their target values. This paper proposes the fuzzy tension control, which is developed to minimize the width deviation of the hot strip by maintaining the proper strip tension between stands and to achieve the stable operation of the coupled looper system. The fuzzy tension control performance is compared with the conventional PID control by experimental results.

• 한국의류산업학회지
• /
• 제7권6호
• /
• pp.673-679
• /
• 2005

This study surveys the fabric surface properties such as mean value of the coefficient of friction(MIU), mean deviation of the coefficient of friction(MMD) and mean deviation of surface roughness(SMD) due to warp and weft tension differences using KES-FB system. For this purpose, fabric is designed as 5 harness Satin weave using 150d/48f warp and 200d/384f weft polyester filaments, and is woven by Omega$^{(R)}$ rapier loom by Textec Co.Ltd and Vamatex-P1001ES$^{(R)}$ rapier loom by Vamatex Co.Ltd respectively. These grey fabrics are processed on the same dyeing and finishing processes. The fabric surface properties according to the weaving looms are analysed with warp and weft weaving tensions. And also surveyed the difference of fabric surface properties according to the fabric positions such as center and each edge of fabrics for the sensitive garment. Fabric thickness was also measured and discussed according to the fabric positions such as center and each of fabrics with two looms weaving tensons.

• Journal of Advanced Marine Engineering and Technology
• /
• 제20권4호
• /
• pp.101-107
• /
• 1996

This test was performed on the hydraulic automatic gauge control(AGC) system of adaptive mass flow method. Fundamental purpose of this study are performance evaluation of this AGC system under the actual rolling condition. It was concluded that the response of AGC system depends on the dynamic characteristics of a reel motor or roll position. The test results are as follows : 1) The control method of reel motor current is better than than of the roll position as AGC system. 2) The more steel strip thickness of delivery side is thick, the larger the gauge deviation is large, and the more it is thin, the larger the gauge deviation rate is large. 3) Because the gauge deviation is large at acceleration and deceleration speed than steady speed, so AGC system is better to adopt over 50m/min. By applying this AGC system, not only the accurary in strip thickness were improved but also productivity was improved dramatically.

• 감성과학
• /
• 제7권4호
• /
• pp.25-33
• /
• 2004

본 연구에서는 경사와 위사의 장력에 기인되는 감성 봉제용 직물의 마찰특성을 KES-FB 계측기를 이용하여 분석하였다. 직물의 마찰특성은 직물표면의 마찰계수, 마찰계수의 평균편차, 그리고 표면요철도를 측정하였다. 이들 표면특성치를 분석하기 위해서 75d/36f PET 필라멘트를 경사로 사용하고 100d/192f PET 필라멘트를 위사로 사용하여 5매 주자직 직물을 Omega와 Picanol 직기에서 각각 제직하고 이들을 같이 연결하여 염색가공 공정을 진행시켰다. 이들 가공된 직물의 직물표면특성은 제직시 측정된 경사와 위사의 장력특성과 함께 분석되어 졌으며 직물의 중앙부위와 양 셀베지 부분의 직물 위치에 따른 표면특성의 차이가 분석되어졌다.

• 한국정밀공학회지
• /
• 제13권5호
• /
• pp.67-73
• /
• 1996

The necessity for more accurate automatic flatness control(AFC) system has increased of customers' requirement for cold rolled steel sheet. Therefore, many cold rolling mills replaced its AFC system with a measuring roll of the contact type form the non-contact type. In this paper. The performance of AFC system of contact type has been investigated under industrial conditions. It has two kinds of actuator: roll bender, spot cooling system. The test results are as follows: The more strip thickness is thick, the smaller the I value, and the more it is thin, the bigger the I value. And a complex distribution of strip tension was controlled, for example, not only a pocket wave but also a simple center wave and edge wave. Because the tension deviation is larger at acceler- ation speed and decelerationspeed than steady speed, AFC system of contact type is better to adopt over 50m/mim. AFC system reduces rapidly large flatness deviation. The maximum I value of strip has been decreased to 13 I, and sticker, defects caused by poor flatness, have been decreased about 60%.

• Journal of Welding and Joining
• /
• 제19권5호
• /
• pp.486-491
• /
• 2001

The effect of S content in welding wires on spattering characteristics and droplet transfer phenomena was studied. In MAG welding using 80%Ar-$20%CO_2$ shielding gas, spattering characteristics and droplet transfer phenomena were varied with S content of wire. Sulfur addition in wire reduced surface tension of droplet and weld pool, and made arc more stable in MAG welding. With increasing S content, the spattering ratio and the ratio of large size spatter ($d{\geq}1.0mm$) were reduced in short circuit transfer mode. In spray transfer mode, spattering ratio, however was increased when sulfur was added more than 0.020wt.% because surface tension of droplets and weld pool was reduced too much even though arc stability was improved.

• 제어로봇시스템학회논문지
• /
• 제15권3호
• /
• pp.330-336
• /
• 2009

This paper studies on the new control algorithm for the mass-flow stabilization in strip head part of a hot strip mill. A new strip tension model in the strip head part is derived using the current deviation of two neighboring stands. The current deviation means a difference between a measured current and a lock-on current, where the lock-on current is set up when a strip tension or a looper angle reaches each target value or time is about 0.4sec, respectively. On the basis of the tension calculation model, a mill velocity of a backward stand is controlled to stabilize a strip mass-flow by PI control algorithm. Therefore, the mass-flow control for strip head part is executed from a metal-in time into a foreward stand till the looper works normally. It is known by the results of a computer simulation and an experiment that the proposed control algorithm is very effective in stabilizing the mass flow of the strip head part.