• The Korean Journal of Nuclear Medicine Technology
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• v.12 no.3
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• pp.192-198
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• 2008

Purpose: The scan time reduction helps to yield more accurate results and induce the minimization of patient's motion. Also we can expect that satisfaction of examination will increase. Nowdays medical equipment companies have developed various programs to reduce scan time. We used Onco. Flash (Pixon method, SIEMENS) that is an image processing technique gated cardiac blood pool scan and going to evaluate its clinical usefullness. Materials and Method: We analyzed the 50 patients who were examined by gated blood pool scan in nuclear medicine department of Asan Mediacal Center from June $20^{th}$ 2008 to August $14^{th}$ 2008. We acquired the Full-time (6000 Kcounts) and Half-time (3000 Kcounts) LAO image in same position. And we acquired LVEF values ten times from Full-time, Half-time images acquired by the image processing technique and analyzed its mean and standard deviation values. To estimate LVEF in same conditions, we set automatic location of the LV ROI and background ROI based on same X and Y-axis. Also we performed blinding tests to physician. Results: After making a quantitative analysis of the 50 patients EF values, each mean${\pm}$standard deviation is shown at Full-time image $68.12{\pm}7.84%$, Half- time (acquired by imaging processing technique) $68.49{\pm}8.73%$. In the 95% confidence limit, there was no statistically significant difference (p>0.05). After blinding test with a physician for making a qualitative analysis, there was no difference between Full-time image and Half-time image acquired by the image processing technique for observing LV myocardial wall motion. Conclusion: Gated cardiac blood pool scan has been reported its relatively exact EF measured results than ultrasound or CT. But gated cardiac blood pool scan takes relatively longer time than other exams and now it needs to improve time competitive power. If we adapt Half-time technique to gated cardiac blood pool scintigraphy based on this study, we expect to reduce possible artifacts and improve accessibility as well as flexibility to exam. Also we expect patient's satisfaction.

• Journal of Music and Human Behavior
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• v.12 no.2
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• pp.37-60
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• 2015

The purpose of this study was to systematically review music intervention studies for patients with schizophrenia. The researcher searched nine electronic databases for clinical trials published since 2000, using combinations of keyword related to schizophrenia and music interventions. The initial search identified 272 studies, and fifteen studies were selected by reviewing the titles, abstracts and full articles, In addition, three articles were added by examining other review articles. Thus, a total of 18 articles were analyzed in terms of their general and intervention characteristics, and the PEDro scale was used to evaluate the methodological quality of the included studies. The results demonstrated that, due to the lack of randomization and blinding, the methodological qualities of the studies with high quality music interventions were often rated low. Eight Music interventions conducted by qualified music therapists included active music-making, therapeutic relationship, and supervision systems for improving intervention quality. In conclusion, the randomization, blinding, and the therapeutic rationale of intervention are recommended in future clinical trials for patients with schizophrenia.

• Journal of Acupuncture Research
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• v.27 no.1
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• pp.117-127
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• 2010

Background : To demonstrate the efficacy of moxibustion therapy, randomized controled trials are required. But, clinical trials of moxibustion had limitations due to the absence of a sham moxibustion model for an appropriate placebo. Objectives : To develop a new sham moxibustion model based on the thermal characteristics of commercial indirect moxibustion, especially temperature, and to evaluate whether it could be applied in clinical trials. Methods : By applying heat insulation, we created a sham moxibustion device that was indistinguishable from a real one with the naked eye. It also stimulated heat but had inert remedial value. A clinical trial was performed on subjects to test double blinding. The subjects were randomly assigned into two groups, a treatment group and a sham group. Acupoint Zusanli($ST_{36}$) was used in each group for 3 times. A sham acupuncture credibility questionnaire was modified into a moxibustion credibility questionnaire and was filled out after treatment. Results : No major difference was detected in the subjects' baseline data. Most subjects and practitioners could not distinguish the sham moxibustion device from the real one. But, subjects who had experience of moxibustion therapy more likely to distinguish the sham moxibustion device from the real one than subjects who didn't have experience of moxibustion therapy. The treatment group showed a significant difference in the VAS(Visual Analog Scale) for intensity of sensation during treatment than that of the sham group. Conclusions : The sham moxibustion device in this study is proved sufficient and credible to be applied in investigations of the effect of moxibustion. But it is more appropriate for the people who don't have experience of moxibustion therapy.

• The Journal of Korean Obstetrics and Gynecology
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• v.20 no.3
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• pp.200-212
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• 2007

Purpose: To find objective validity of minimal acupuncture using a modified guide tube as a method to verify the effect of acupuncture. Methods: Subjects of this study were participants of a randomized clinical trial which was practiced to verify the effect of acupuncture on postmenopausal hot flash. There were 2 arms of treatment, one's for active acupuncture group(AG) with manipulation and De qi, the other's for minimal acupuncture group(MG) using a modified guide tube which was designed to give minimal stimulation to the patient. After 8 weeks' treatment followed by 4 weeks' observation, participants were asked to fill in self-report forms on their education, previous experiences of acupuncture, original idea on the efficacy of acupuncture and recognition of blinding. Results: 19 participants of 26 in AG and 19 of 26 in MG completed the self-report form. There was no difference between AG and MG in their education(p=0.5976, Fisher exact test) and previous experiences of acupuncture(p=0.9999, Fisher exact test). In their original ideas on the efficacy of acupuncture, most of AG and MG respondents have been thought that acupuncture is very effective or quite effective, and there was no difference between 2 groups(p=0.5065). 16 of 19 in AG and 14 of 19 in MG believed that they underwent more effective way, there was no statistical difference between 2 groups(p=0.6928, Fisher exact test). Participants believed in undergoing more effective way not because they recognized treatment method, but they were satisfied with the effectiveness of treatment retrospectively. Conclusion: As the result of this study, these authors suggest that minimal acupuncture using a modified guide tube is acceptable as a method to verify the effect of acupuncture in acupuncture-familiar Korean culture. Also further studies on the stimulation-specific effect of minimal acupuncture are demanded.

• Aerospace Engineering and Technology
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• v.4 no.1
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• pp.66-76
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• 2005

In this study, star visibility analysis of a star tracker is performed by using a statistical apprach. The probability of the Sun and the Earth proximity, the solar array masking probability, and the solar array blinding probability by the Sun light are obtained from the arbitrary chosen satellite positions as a function of a line of sight vector of the star tracker in several satellite attitude modes. This analysis demonstrates that the optimized star tracker accomodations can be determined to be an elevation angle -40o and two azimuth angles $-35^{circ}$ and $-150^{circ}$.

• Journal of Astronomy and Space Sciences
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• v.28 no.4
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• pp.345-354
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• 2011

Earth acquisition is to solve when earth can be visible from satellite after Sun acquisition during launch and early operation period or on-station satellite anomaly. In this paper, the algorithm and test result of the Communication, Ocean and Meteorological Satellite (COMS) Earth acquisition are presented in case of on-station satellite anomaly status. The algorithms for the calculation of Earth-pointing attitude control parameters including those attitude direction vector, rotation matrix, and maneuver time and duration are based on COMS configuration (Eurostar 3000 bus). The coordinate system uses the reference initial frame. The constraint calculating available time-slot to perform the earth acquisition considers eclipse, angular separation, solar local time, and infra-red earth sensor blinding conditions. The results of Electronics and Telecommunications Research Institute (ETRI) are compared with that of the Astrium software to validate the implemented ETRI software.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.5
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• pp.985-991
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• 2015

The user's secret key can be retrieved by various side channel leakage informations occurred during the execution of cryptographic RSA exponentiation algorithm which is embedded on a security device. The collision-based power analysis attack known as a serious side channel threat can be accomplished by finding some collision pairs on a RSA power consumption trace. Recently, an RSA exponentiation algorithm was proposed as a countermeasure which is based on the window method adopted combination of message blinding and exponent splitting. In this paper, we show that this countermeasure provides approximately $2^{53}$ attack complexity, much lower than $2^{98}$ insisted in the original article, when the window size is two.

• Korean Journal of Acupuncture
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• v.25 no.2
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• pp.57-69
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• 2008

Objectives : To review the controlling methods used in RCTs (randomized controlled trials) of auricular acupuncture. Methods : To investigate the controlling methods used in clinical trials of auricular acupuncture, 46 articles were retrieved from PUBMED (from August 1976 to August 2007, with limits: english, clinical trial) using the key words of "ear acupuncture", "auricular acupuncture", "auriculo-medicine", and sorted out according to the types of control treatments. Among them, 10 articles were selected based on STRICTA (Standards for Reporting Intervention in Controlled Trials of Acupuncture), and the controlling methods used in those articles were reviewed. Results : In clinical trials of auricular acupuncture, 'sham acupoints (non-acupoints and non-treatment acupoints included)', 'minimal acupuncture', 'pseudo-intervention', and 'placebo devices' have been used as controlling methods, but their 'inactivity' have been in question. To compensate the disadvantages of 'minimal acupuncture', and 'pseudo-intervention' control, placebo auricular acupuncture needles have been developed, although these needles didn't satisfy the conditions of 'blinding' and 'physical inactivity' simultaneously. Conclusions : Further researches on 'sham acupoints' and new development of 'placebo auricular acupuncture needles' are needed.

• Bulletin of the Korean Space Science Society
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• 2008.10a
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• pp.28.2-28.2
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• 2008

Recently, star sensors have been successfully used as main attitude sensors for attitude control in many satellites. This research presents the star visibility analysis for star trackers and the goal of this analysis is to make sure that the star tracker implementation is suitable to the mission profile and scenario and satisfies the requirement of attitude orbit control system. As a main optical attitude sensor imaging stars, accomodations of a star tracker should be optimized in order to improve the probability of the usage by avoiding the blinding (the unavailability) by the Sun and the Earth. For the analysis, a statistical approach and a time simulation approach are used. The statistical approach is based on the generation of numerous cases, to derive relevant statistics about Earth and Sun proximity probabilites for different lines of sight. The time simulation approach is performed for one orbit to check the statistical result and to refine the statistical result and accomodations of star trackers. In order to perform simulations first of all, an orbit and specific mission profiles of a satellite are set, next the earth proximity probability and the sun proximity probability are calculated by considering the attitude maneuvers and the geometry of the orbit, and then finally the unavailability positions are estimated. As a result, the optimized accomodations of two star trackers are suggested for the low earth orbit satellite.

• Journal of KIISE:Computer Systems and Theory
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• v.29 no.5
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• pp.299-306
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• 2002

Partially blind signature scheme is used in applications such as electronic cash and electronic voting where the privacy of the signature requester is important. This paper proposes an RSA-based enhanced partially blind signature scheme minimizing the amount of computation of the signature requester. The signature requester needs computation in blinding the message to the signer and in generating the final signature using the intermediate signature generated by the signer. Since the proposed scheme enables the signature requester to get the final signature just by using modular additions and multiplications, it decreases computation of the signature requester considerably. So, the proposed partially blind signature scheme is adequate for devices such as mobile device, smart-card, and electronic purse that have relatively low computing power.