• The Journal of Korea Robotics Society
• /
• v.19 no.1
• /
• pp.8-15
• /
• 2024

This paper proposes a linear model predictive control of 6-DOF remotely operated underwater vehicles using nonlinear robust internal-loop compensator (NRIC). First, we design a integrator embedded linear model prediction controller for a linear nominal model, and then let the real model follow the values calculated through forward dynamics. This work is carried out through an NRIC and in this process, modeling errors and external disturbance are compensated. This concept is similar to disturbance observer-based control, but it has the difference that H_∞ optimality is guaranteed. Finally, tracking results at trajectory containing the velocity discontinuity point and the position tracking performance in the disturbance environment is confirmed through the comparative study with a traditional inverse dynamics PD controller.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.18 no.5
• /
• pp.624-631
• /
• 2008

This paper presents a method for a mobile robot to follow a moving object in real time. The robot follows a target object keeping the facing angle toward the target and the distance to the target to given value. The method consists of two procedures: first, the detection of target position in the robot coordinate system, and the second, the calculation of translational velocity and rotational velocity to follow the object:. To detect the target location, range sensor data is represented in histogram. Based on the real time calculation of the location of the target relative to the robot, translational velocity and rotational velocity to follow the target are calculated. The velocities make the heading angle and the distance to target converge toward the desired ones. The performance of the method is tested through simulation. In the simulation, the target moves with three different trajectories, straight line trajectory, rectangular trajectory, and circular trajectory. As shown in the results, it is inevitable to lose track temporarily of the target when the target suddenly changes its motion direction. Nevertheless, the robot speeds up to catch up and finally succeeds to follow the target as soon as possible even in this case. The proposed method can also be utilized to coordinate the motion of multiple robots to keep their formation as well as to follow a target.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.1
• /
• pp.109-117
• /
• 2015

Background: Follow-up clinical consultations could improve overall health status as well provide knowledge and education for cancer prevention. Materials and Methods: This is the cross-sectional study using the Korean Community Health Survey (KCHS) 6th edition for 2012, with 115,083 respondents who underwent cancer checkups selected as subjects. Associations between the presence of consultation and the socioeconomic status were determined using statistical methods with the SAS 9.3 statistical package (Cary, NC, USA). Findings: Among the recipients, 32,179 (28.0%) received clinical consultations after cancer screenings. Those in rural areas (odds ratio, OR=0.71, 95% confidence interval (CI), 0.69-0.73) visited follow-up clinics less frequently than did those in urban areas. Starting at the elementary school level, as the education level increased to middle school (OR=1.26, 95% CI: 1.19-1.34), high school (OR=1.29, 95% CI: 1.23-1.36) or college (OR=1.76, 95% CI: 1.65-1.89), the participation rates also increased. When compared with the lowest quartile group, the quartile income level showed a statistical trend and difference as follows: second lowest quartile (OR=1.11, 95% CI: 1.07-1.16), third lowest (OR=1.12, 95% CI: 1.07-1.17) and highest quartile income (OR=1.29, 95% CI: 1.23-1.35). In addition, the people with economic activities (OR=0.87, 95% CI: 0.84-0.90) visited follow-up clinics less frequently than did the others. Current smokers (OR=0.93, 95% CI: 0.89-0.98) and inveterate drinkers (OR=0.88, 95% CI: 0.85-0.94) had a tendency to visit less often than did non-smokers and other drinkers with all cancers combined. Interpretation: We suggest primary prevention through lifestyle modifications including smoking and drinking, and environmental interventions may offer the most cost-effective approach to reduce the cancer burden.

• Korean Journal of Psychosomatic Medicine
• /
• v.11 no.2
• /
• pp.205-213
• /
• 2003

Objectives: The authors intended to evaluate long-term outcome of group cognitive behavioral therapy(GCBT) for panic disorder and examined the variables to predict high end-state functioning in 12 months follow-up. Methods: 236 patients meeting DSM-IV criteria for panic disorder were assessed by STAI, ASI, BDI, BSQ, PBQ, ACQ at pre & post treatment, and were asked about the frequency of panic attacks during recent one month. We executed stepwise discriminant analysis on the clinical variables at pre treatment assessment to find the variables for discriminating between high end-state function(HES) and low end-state function(LES). Results: After GCBT, 82.6% of panic patients maintained high end-state functioning at 12 months follow-up. The results of discriminant analysis showed that BDI and BSQ at pre treatment assessment were significant variables to predict end-state functioning at 12 months follow-up. The hit ratio of discriminant analysis was 69.2%. Conclusion: These results suggest that the therapeutic effect of GCBT can be maintained through 12 months. Especially, it is likely that patients who were less depressed and who had less experienced the fear of physical symptoms at pre-treatment can maintain HES.

• The Korean Journal of Nuclear Medicine
• /
• v.9 no.1
• /
• pp.51-58
• /
• 1975

It is a great value to find an early detection of involvement of ureteric obstruction in the carcinoma of cervix. Little or no knowledge of the condition of the kidneys or the lower urinary tract are able to elucidate by the biochemical studies such as blood nitrogen or urine creatinine in carcinoma of cervix. Findings of urography delineates the condition of urinary tract stasis in the renal pelvis and ureters, however, slight stasis maybe difficult to demonstrate. On the other hand isotope nephrography is accepted as a sensitive method to observe renal function especially in regarding to the excretory function of kidney. It was attempted to analysis the findings of urography conjunction with isotope nephrography in 50 cases of unselected patients with invasive carcinoma of cervix through pre and post irradiation follow up studies. Urography was done as a routine procedure and.analysed emphasising changes of collecting systems and ureter condition. Isotope nephrography was carried out by means of $15{\mu}ci\;I^{131}$-Hippuran injected intravenously and the curves were analysed as follows. Parameter were; time of maximum amplitude ($T_{max}$), half time of maximum amplitude ($T\frac{1}{2}$), Kac and Kex value calculated from these two parameters in Tobe's method. The excretion index by Aurell defines the ratio between the maximum activity and the activity measured on the slope of the third phase ten minites after it has reached its maximum. Results: 1. 28.8% had an abnormal IVP suggestive of ureteric involvement before irradiation therapy and the patient of stage III and IV were the great part. 2. 21.7% had abnormal findings of per-irradiation renogram whom showed normal IVP. The other group showed normal IVP which group also showed normal renogram prior irradiation. 3. The more severe the ureteric involvement, the change of excretion index was greater. 4. Even in stage I and II patient, abnormal renogram was revealed in 12 cases (39.4%) among 31 cases. 5. All cases of TAH showed abnormal findings of IVP and renogram. 6. No. definite change of renogram was obtained just after the irradiation therapy (point $A:8000{\sim}9000rads,\;B:5000{\sim}6000rads,\;Co:11000{\sim}13000rads$). Each 3 month follow up study was performed and comparing with preirradiation study which showed significant changes of excretion index of renogram were 42.8% in $6{\sim}9$ month follow-up and 75% in $9{\sim}12$ month, respectively. 7. It seems to be important to observe the parameter Kex and excretion index of renogram to determine early abnormality of kidney excretory function by means of post-irradiation follow up study.

• Journal of The Korean Society of Integrative Medicine
• /
• v.9 no.2
• /
• pp.119-130
• /
• 2021

Purpose : We aimed to validate a new manual therapy to treat tension type headache(TTH) by applying myofascial release techniques to the scalp and to examine the changes in the quality of life and the headache characteristics after treatment and at the 6-month follow-up. Methods : Thirty patients were recruited in this study and were assigned to two groups through simple random sampling. Fifteen patients were assigned to the manual therapy group (MT) and 15 patients to the scalp myofascial release technique (SMT) group. However, five patients from the MT group and one from the SMT group were excluded. Therefore, 24 patients with TTH (10 males, 14 females) participated in the study. Patients underwent either MT or SMT. The procedures were performed by a physical therapist twice per week for 4 weeks. The quality of life [using the brief pain inventory (BPI) and the headache impact test (HIT)], and the frequency, duration, and intensity of the headache [on a visual analog scale (VAS)] were assessed before and after the treatment, and at the follow-up. Results : After 4 weeks of SMT, the frequency (p<.001), duration (p<.05), and intensity (p<.001) of the headache and the quality of life (HIT; p <.001, BPI; p<.001) significantly improved in the patients with TTH. The improvement in these parameters remained significant even after 6 months of follow-up. Similarly, After 4 weeks of MT, the frequency (p<.05), duration (p<.05), and intensity (p<.01) of the headache, and the quality of life (HIT; p<.05, BPI; p<.001) significantly improved in the patients with TTH. The improvement in these parameters remained significant even after 6 months of follow-up. There was no significant difference in these parameters between the two groups. Conclusion : It has been suggested that MT using the SMT can be used as a non-invasive treatment to treat the frequency, duration, and intensity of the TTH, and to improve the quality of life.

• Proceedings of the KIPE Conference
• /
• 1996.06a
• /
• pp.5-12
• /
• 1996

In this paper, we design a Continuous Variable Structure Controller which can control robot manipulators to follow the desired planned trajectory with accuracy and robustness, and improve continuity and robustness of variable structure control, based on disturbance observer. We also analyze the stability the proposed algorithm and then verify the usefulness and performance through simulation stuies.

• Journal of Chest Surgery
• /
• v.19 no.2
• /
• pp.358-362
• /
• 1986

Esophageal atresia and tracheoesophageal fistula may occur as separate entities but usually occur in combination. Recently we were experienced a case of esophageal atresia with distal tracheoesophageal fistula in infant patient who presented the symptoms of projectile vomiting and dyspnea. The diagnosis was made by the esophagography and the Haight`s operation was performed transpleurally through 4th intercostal space after gastrostomy. Operative patient tolerated all the operative procedures well in spite of postoperative respiratory complication and recovered uneventfully, permitted feeding on 10th postoperative day. On follow up study after 5th months, Patient reveals good health without other problem.

• Proceedings of the Acoustical Society of Korea Conference
• /
• 1998.06c
• /
• pp.239-242
• /
• 1998

A new real time sound field visualization technique is introduced in this study using PIV(Particle Imaging Velocimetry) technique. Small particles of which density is small enough to follow up the air flow are used for sound visualization. When the driving frequency is in the vicinity of the resonance frequency of the simplified 2-dimensional muffler system, an acoustic streaming is shown and of which velocity distribution is obtained through PIV technique. It is experimentally proved that the present technique is able to visualize and quantify the sound field's energy flow.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1995.04a
• /
• pp.124-129
• /
• 1995

In this study proposed to rapid and simple methid of test for early evaluation of strength of cement. The obtained results through a series of experiment are summarized as follow. The resistance ratio was decreased as the increase of water-cement ratio. The compressive strength of cement was increased as the resistance ratio increase. The experimental results of compressive strength of cement is shown in the same value no relation with the kind of cement respectively.