• International Journal of Aeronautical and Space Sciences
• /
• v.11 no.2
• /
• pp.118-125
• /
• 2010

This paper describes a mid-course guidance strategy based on the earliest intercept geometry (EIG) guidance. An analytical solution and performance validation will be addressed for generalized mid-course guidance problems in area air-defence in order to improve reachability and performance. The EIG is generated for a wide range of possible manoeuvres of the challenging missile based on the guidance algorithm using differential geometry concepts. The main idea is that a mid-course guidance law can defend the area as long as it assures that the depending area and objects are always within the defended area defined by EIG. The velocity of Intercept Point in EIG is analytically derived to control the Intercept Geometry and the defended area. The proposed method can be applied in deciding a missile launch window and launch point for the launch phase.

• Journal of Advanced Navigation Technology
• /
• v.2 no.2
• /
• pp.84-99
• /
• 1998

As a part of closed-loop guidance law studies for anti-ballistic missile defense, a mid-course guidance law is proposed to engage the target with the predetermined attitude for increased terminal effectiveness. The proposed guidance law is based on the predicted target position calculated from a simplified solution of target motion and the estimates of an extended Kalman filter utilizing noisy nonlinear radar measurements. Extension of the proposed mid-course guidance to 3 dimensional engagements are also studied. Performance of the proposed mid-course guidance law together with a terminal guidance law in the form of conventional proportional navigation guidance is evaluated by a series of simulation studies.

• Archives of Plastic Surgery
• /
• v.45 no.2
• /
• pp.152-157
• /
• 2018

Background Intraoperative indocyanine green (ICG) lymphography can effectively detect functioning lymph vessels in edematous limbs. However, it is sometimes difficult to clearly identify their course in later-stage edematous limbs. For this reason, many surgeons rely on experience when they decide where to make the skin incision to locate the lymphatic vessels. The purpose of this study was to elucidate lymphatic vessel flow patterns in healthy upper extremities in a Korean population and to use these findings as a reference for lymphedema treatment. Methods ICG fluorescence lymphography was performed by injecting 1 mL of ICG into the second web space of the hand. After 4 hours, fluorescence images of lymphatic vessels were obtained with a near-infrared camera, and the lymphatic vessels were marked. Three landmarks were designated: the radial styloid process, the mid-portion of the cubital fossa, and the lower border of the deltopectoral groove. A straight line connecting the points was drawn, and the distance between the connected lines and the marked lymphatic vessels was measured at 8 points. Results There were 30 healthy upper extremities (15 right and 15 left). The average course of the main lymph vessels passed $26.0{\pm}11.6mm$ dorsal to the styloid process, $5.7{\pm}40.7mm$ medial to the mid-cubital fossa, and $31.3{\pm}26.1mm$ medial to the three-quarters point of the upper landmark line. Conclusions The main functioning lymphatic vessel follows the course of the cephalic vein at the forearm level, crosses the mid-cubital point, and travels medially toward the mid-axilla.

• 한국노년학
• /
• v.31 no.3
• /
• pp.445-461
• /
• 2011

The purpose of this study was to examine if there was difference of psychological well-being in mid adulthood on experience of life events and social support in pre-adulthood and the effects of life events and social support in pre-adulthood on psychological well-being in mid adulthood fromlife course perspective. The data came from 511 mid-life adults aged from 40 to 59. The main results were as follows: (1) middle aged who were experienced life events concerning school, parent, violence, and death in pre-adulthood showed lower psychological well-being than those who didn't experience life events in pre-adulthood. Psychological well-being of middle aged who received social support in emotional, material, and informational area in pre-adulthood was higher than one of the whom didn't receive social support in pre-adulthood. (2) the experienced life events concerning parent, violence, and death in pre-adulthood effect on psychological well-being in mid adulthood. Also, the received emotional support and informational support in pre-adulthood influence on psychological well-being in mid adulthood. And there were adjusting effects of life events concerning parent and received informational support in pre-adulthood on the psychological well-being in mid adulthood. These findings support life course perspective that past experiences have cumulative and interconnected effect and the individual life was closely connected with other people having meaningful relationships. Also, the intervention on psychological well-being requires not only prevent life events but augment social support that can protect after experience of life events. The intervention should suggest suitable and specific method on life events.

• Industrial Engineering and Management Systems
• /
• v.11 no.2
• /
• pp.196-201
• /
• 2012

This study has developed a packaging criterion to minimize the level of discomfort which drivers using their vehicles for daily life purposes may experience due to ill designed vehicle packaging of mid-size sedan based on users' daily-life scenario. To find out optimal range of packaging dimension criterion, discomfort levels the test participants with different physical conditions suffer while performing various activities were analyzed. One hundred two test participants were carefully selected to represent entire Korean mid-size sedan owner-drivers. They were directed to test drive on the course designed to simulate mid-size sedan daily-usage scenario. At pre-designed locations, each of questions was asked to the test participants to be answered in the form of 10 point discomfort level score. By analyzing the test results, the optimal range for packaging dimensions was defined to be used as a packaging criterion.

• Journal of Aerospace System Engineering
• /
• v.10 no.4
• /
• pp.35-40
• /
• 2016

Mid-course correction maneuvers (MCCMs) are necessary to correct the launch-vehicle dispersion to go to the Moon. There were 3 or 4 MCCMs needed for a direct transfer trajectory. But the strategy for MCCMs of the phasing-loop trajectory is different, because it has a longer trans-lunar trajectory than direct transfer does. An orbiter using a phasing-loop trajectory has several rotations of the Earth, so the orbiter has several good places, such as perigee and apogee, to correct the launch-vehicle dispersion. Although launch dispersion is relatively high, the launch vehicle is not as accurate as we expected. A good MCCM strategy can overcome the high dispersion by using small-magnitude correction maneuvers. This paper describes the phasing-loops sequence and strategy to correct high launch-vehicle dispersions.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.49 no.1
• /
• pp.21-30
• /
• 2021

Mid-course trajectory of the missiles equipped with seeker should be designed to detect target within FOV of seeker and to maximize the maneuverability at the point of transition to terminal guidance phase. Because the trajectory optimization problems are generally hard to obtain the analytic solutions due to its own nonlinearity with several constraints, the various numerical methods have been presented so far. In this paper, mid-course trajectory optimization problem for boost-glide missiles is calculated by using SOCP (Second-Order Cone Programming) which is one of convex optimization methods. At first, control variable augmentation scheme with a control constraint is suggested to reduce state variables of missile dynamics. And it is reformulated using a normalized time approach to cope with a free final time problem and boost time problem. Then, partial linearization and lossless convexification are used to convexify dynamic equation and control constraint, respectively. Finally, the results of the proposed method are compared with those of state-of-the-art nonlinear optimization method for verification.

• Journal of Chest Surgery
• /
• v.25 no.12
• /
• pp.1432-1435
• /
• 1992

Congenital bronchoesophageal fistula without esophageal atresia is very rare and often has an insidious clinical course that occaisionally persists into adult life. A 54-year-old female patient presented at our emergency room with a complaint of hemoptysis and dyspnea. Esophagogram revealed a fistula tract between mid-low esophagus and right superior segmental brochus of lower lobe. Fistulectomy was performed without problem. The postoperative course was uneventful.

• Journal of the Korean Society of Radiology
• /
• v.15 no.5
• /
• pp.675-681
• /
• 2021

Recently, the Ministry of Education stipulates in the distance class operation regulations that student lecture evaluations for distance learning subjects should be conducted at least twice per semester and the results should be disclosed to students. Therefore, the lecture evaluation of D college was compared with the first semester of 2020 and the first semester of 2021. As for the multiple-choice evaluation result of the distance learning mid-course evaluation, the overall average of the mid-course evaluation of the distance class in the first semester of 2020 increased from 4.1819 to 4.4000 in the mid-course evaluation in the first semester of 2021.In the case of the first semester of 2020, due to Corona 19, all non-face-to-face classes were held, but in the first semester of 2021, face-to-face classes increased. The overall satisfaction level rose from 4.18 points in the first semester of 2020 to 4.39 points in the first semester of 2021. The screen composition, sound and picture quality, playback time, face appearance, lecture material provision, and frequency of use of the top 3% and bottom 3% also increased. Despite the changes caused by the LMS replacement, which was a concern, student attendance, assignments, and test submission rates also increased compared to the previous year. The null hypothesis that 'the difference between the two scores is the same' is the null hypothesis because the probability of significance is 0.000 and less than 0.05 in the case of the best 3% of the test result of the test result of the mid-course evaluation of distance classes in the first semester of 2020 and the evaluation of the intermediate lectures in the first semester of 2021. As this was rejected, it can be seen that the best score for the 2021 school year has significantly increased compared to the first semester of 2020. Also, in the case of Worst 3% or less, the significance probability is 0.000, which is less than 0.05, so the null hypothesis that 'the difference between the two scores is the same' was rejected, indicating that the Worst score for the 2021 school year was significantly higher than that for the first semester of 2020.

• International Journal of Contents
• /
• v.15 no.3
• /
• pp.7-12
• /
• 2019

The purpose of this study was to analyze characteristics and patterns of 'better class' by using the longitudinal text mining big data analysis technique from subjective lecture evaluation comments. First, this study classified upper 30% classes to deduce certain characteristics and patterns from every five-year subjective text data for 10 years. A total of 47,177courses (100%) from spring semester 2005 to fall semester 2014 were analyzed from a university at a metropolitan city in the mid area of South Korea. This study extracted meaningful words such as good, course, professor, appreciation, lecture, interesting, useful, know, easy, improvement, progress, teaching material, passion, and concern from the order of frequency 2005-2009. The other set of words were class, appreciation, professor, good, course, interesting, understanding, useful, help, student, effort, thinking, not difficult, explanation, lecture, hard, pleasant, easy, study, examination, like, various, fun, and knowledge 2010-2014. This study suggests that the characteristics and patterns of 'better class' at college, should be analyzed according to different academic code such as liberal arts, fine arts, social science, engineering, math and science, and etc.