• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.35 no.11B
• /
• pp.1725-1731
• /
• 2010

In this paper, we proposed preamble structure and code acquisition method to improve code acquisition performance for DS-SS/TDMA packet communication systems. Proposed algorithm changes the short PN code position depending on the sub slot number. Proposed algorithm also saves position differences between short PN codes and position offsets between short PN codes and data starting position of the TDMA packet. By using the position difference table, proposed algorithm can find out exact data starting position even though some sub slots were defected. As a result of simulation, we concluded that proposed algorithm has at least 5dB gain compared to conventional method when same short PN code is used. Moreover, proposed algorithm shows same code acquisition performance only with 1/4 shortened short PN code compared to conventional method.

• 제어로봇시스템학회:학술대회논문집
• /
• 2000.10a
• /
• pp.410-410
• /
• 2000

Impedance control is recognised as one of the most proper control scheme to carry out the assembly tasks, since it can control the dynamic relationship between the manipulator and environment directly. However, it is well known that the contact force cannot be controlled directly using the impedance control. Also impedance parameters should be properly defined depending on the task to be performed. We propose a new position based impedance control, which has self-adjusted impedance parameters and can control the contact force explicitly, Impedance parameters, as time-varying parameters, are adjusted automatically based on the measured contact force and the position error during the task. A proposed algorithm was implemented on the peg-in-hole task with the industrial manipulator. We shows the effectiveness of proposed control method experimentally.

• Journal of the Korea Society of Computer and Information
• /
• v.28 no.8
• /
• pp.119-126
• /
• 2023

In this paper, a new model was presented to objectively evaluate the defense ability of defenders in Korean professional baseball. In the proposed model, using Korean professional baseball game data from 2016 to 2019, a representative defender was selected for each team and defensive position to evaluate defensive ability. In order to evaluate the defense ability, a method of calculating the defense range for each position and dividing the calculated defense area was proposed. The defensive range for each position was calculated using the Convex Hull algorithm based on the point at which the defenders in the same position threw out the ball. The out conversion score and victory contribution score for both infielders and outfielders were calculated as basic scores using the defensive range for each position. In addition, double kill points for infielders and extra base points for outfielders were calculated separately and added together.

• Korean Journal of Applied Biomechanics
• /
• v.21 no.1
• /
• pp.57-65
• /
• 2011

This research was conducted to biomechanically analyze Tippelt motion in parallel bars, and establish technical understanding. To achieve that goal, the performances of the Tippelt acts carried out by five world top-class national gymnasts in the parallel bars 3-dimensional cinematographic analysis and EMG analysis were conducted and following conclusion were obtained. The Tippelt motions of excellent national gymnasts perform tap motion through the down swing of a large circular movements, and perform kick-out motion rapidly extending shoulder joint angle and hip joint angle with the trunk in a position close to perpendicular position at the vertical downwardness of the grasping the bars. At this time, if handstand starting the movement is too delayed or rapidly down swung, it was shown that from the initial falling, unnecessary muscular power was wasted in trapezius, anterior deltoid, erector spinae, latissimus dorsi, upper rectus abdominis, lower rectus abdominis. The muscular parts in tap motion generating muscle action potential were pectoralis major, rectus femoris, upper rectus abdominis, lower rectus abdominis, and those in kick-out motion were upper rectus abdominis, lower rectus abdominis, trapezius and anterior deltoid.

• The Korean Journal of Ecology
• /
• v.19 no.2
• /
• pp.107-123
• /
• 1996

The position effects on the abortion of flowers, fruits, and ovules were examined in relation to the resource limitation hypothesis using a temperate legume species, Vicia cracca. Fifty plants were randomly sampled from a natural population located at the Belmont Conservation Site in Belmont, MA, USA. Due to indeterminant growth and acropetal flowering of this species, the position of flower or fruit on the plant was able to be coded by the combination of architectural levels such as plant half (lower and upper half) and inflorescence half (lower and upper half) within each plant half. Overall, only 17.3% of the flowers on an inflorescence began to develop into fruits, while overall 36.0% of the fruits initiated failed to mature. Consequently, 11.5% of the flowers successfully matured into fruits. The mean flower number per inflorescence differed significantly among plants as well as between plant halves. Although the probability of fruit initiation was higher in the lower halves of both plant and inflorescence than in the upper halves of the latter, fruit abortion rate differed significantly only between plant halves. The overall mean seed set was 33.6%, implying that about two out of six ovules in a fruit matured into seeds. The seed set was independent of both plant identity and architectural level unlike other reproductive characters examined. When the ovule developmental stage was examined on data pooled over all fruits, the proportion of ovules in varying developmental stages decreased in order of early abortion, seed maturation, late abortion, and seed predation (48.4, 34.9, 12.2, and 4.5%, respectively). A within-fruit ovule position was also used as a class variable for the analysis of position effects on ovule development. All architectural levels considered exerted singificant influence over the ovule development. In particular, ovule development was strongly affected by the within-fruit ovule position. Ovules in both extreme ends within a fruit tended to abort early, while those in the middle position were more likely to mature into seeds. The strong position effects detected from the flowering to seed maturation stage were interpreted as an indication of competitive interaction among reproductive characters which are largely constrained by plant architecture.

• Archives of Reconstructive Microsurgery
• /
• v.25 no.2
• /
• pp.43-48
• /
• 2016

Purpose: Perforator flap-using ischial sore reconstruction is performed in a prone position. But after the surgery, recurrence frequently occurs in a sitting position. In this sense, we introduce modified flap insetting method which closely resembles patient's sitting position to lessen the flap tension surgically. Materials and Methods: Authors tried to check a skin tension difference between prone position and sitting position in normal people group and to find out the importance of performing flap insetting in hip flexion position. Healthy volunteers were collected (n=20) and designed the same length of 4 divided sections around the ischium. Lengths of each section were measured when hip joint was flexed to 90 degree and when both hip and knee joints were flexed to 90 degree and the statistical evaluation was performed. Twenty cases with ischial sore underwent reconstructive surgery using perforator flap under hip flexion position and followed-up for any recurrences. Results: There was a meaningful difference between the joint flexed skin length and that of the neutral position. Flap showed sufficient thickness over 12 months. Conclusion: It seems that recurrence could be reduced when the reconstructed flap could sufficiently cover in a sitting position regarding its significant length difference in normal people group.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.33 no.11
• /
• pp.858-868
• /
• 2009

A numerical investigation has been carried out about the performance of a 500MW class tangentially coal-fired boiler, focusing on the optimization of separated overfire air (SOFA) position to reduce NOx emission. For this purpose, a comprehensive combination of NOx chemistry models has been employed in the numerical simulation of a particle-laden flow along with solid fuel combustion and heat and mass transfer. A reasonable agreement has been shown in baseline cases for predicted operational parameters compared with experimental data measured in the boiler. A further SOFA calculation has been made to obtain optimum elevation and position of SOFA port. Additionally, clarifying on the effect of SOFA on NOx emission has been carried out in the coal-fired boiler. As a result, this paper is valuable to provide an information about the optimum position of SOFA and the mechanism by which the SOFA would affect NOx emission.

• Journal of the Korean Society of Radiology
• /
• v.6 no.4
• /
• pp.299-303
• /
• 2012

Shoulder MRArthrography was performed to get an accurate diagnosis about complex anatomical structure in shoulder joint. We carried out how the changes of anatomical rotations in shoulder joint could bring certain diagnosis effects on MRI images for various shoulder humerus positions; Neutral position, Internal rotation position and External rotation position. In addition, we prepared an aid tool in oder to maintain the right posture of a patient. This aid tool was made by adapting Modeling Design Program. By virtue of this aid, we obtained the following result. Shoulder MR Arthrography by the External rotation position for anatomical structure diagnosis was the most suitable in diagnostic evaluations of important anatomical structures in shoulder joint such as Biceps tendon, Supera-spiatus tendon, Sub-scapularis tendon, Labrum and Sub-acromial space.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.6 no.3
• /
• pp.85-91
• /
• 2007

This study was carried out to minimize the lifting force of a two hinge type stand mechanism. This unit is designed for the display devices in order to enhance the ergonomics for effective height adjustment and maintenance at any preferred position. The unit will be very useful for the mechanism fabricated with a coil spring and disc springs as a torque generator. The maximum and the minimum torque value should be calculated initially for the smooth lift. And the reasonable torque distribution is necessary to prevent any auto lift and auto dropping at any position because the torque generated by coil spring is more sensitive than disc spring in tilting the position. Therefore, the analysis of the coil spring is requisite to issue the specific torque value depending on the distorted angle with securing reliability of a long time storage condition. After the theoretical torque value was calculated, the evaluation was carried out by making a proto-type sample, then distorted angle was updated by experiment. The result of this study can readily be applied to various units for the optimization of the smooth lift.

• The Journal of Korean Physical Therapy
• /
• v.10 no.2
• /
• pp.77-86
• /
• 1998

The shoulder joint permit ate greatest mobility of any joint area carries out the importment function of stabilization for hand use. So handgrip activity is important to evaluate while assessing shoulder load in manual work. There was an association between static handgrip and shoulder muscle activity. The purpose of this study was to find out the changes of the hand grip strength according to shouter an81e. One hundred (50 female, 50 male) college adult volunteers with no known shoulder dysfunction participated subject in three positions with elbow extension: (1) shoulder $0^{\circ}$ flexion (2) shoulder $90^{\circ}C$ flexion (3)shoulder $180^{\circ}C$ flexion. The paired t-test was used to determine the different in grip strength between right and left hand at shouter position change. All, there was significiant for all three position by right and left shoulder (p<0.001). In mon, the ANOVA results revealed not a significiant F-ratio fer all three position by right and left hand. In woman, revealed significiant (p<0.05).