• Journal of Chest Surgery
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• v.33 no.10
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• pp.812-816
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• 2000

Background ; To evaluate the efficacy of Fibrin glue to decrease recurrence in video-assisted thoracoscopic surgery(VATS) for a treatment of spontaneous penumothorax. Material and Method : All medical records of 17 patients who underwent a thoracoscopic wedge resections of bullae with stapling device with Fibrin glue in our institute between May 1998 and December 1999 were reviewed. variables analyzed include affected sites primary indication of VATS. duration from admission to discharge duration of postoperative stay duration of chest tube drainage recurrence and complication. There were 16 men and 1 woman. Result : There was no evidence of hemodynamic instability or arterial blood gas abnormalities encountered during the procedure. Mean age at the time of the VATS was 26.9 years (range 15 to 61 years) The mean duration from admission to discharge was 7.8 days and mean postoperative stay was 5.1days mean chest tube indwelling period was 4..0 days. There was no recurrence of pneumothorx. Conclusion : Thoracoscopic wedge resections with introduction of fibrin glue are safe and effective and requires only a short hospital stay. We believe that this thoracoscopic technique will further simplify the surgical treatment of pneumothorax.

• Journal of Korean Institute of Industrial Engineers
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• v.43 no.1
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• pp.1-11
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• 2017

Stochastic resource-constrained project scheduling problem is an extension of resource-constrained project scheduling problem such that activity duration has stochastic nature. In real situation where activity duration is not known until the activity is finished, open-loop based static policies such as activity-based policy and priority-based policy will not well cope with duration variability. Then, a dynamic policy based on closed-loop decision making will be regarded as an alternative toward achievement of minimal makespan. In this study, a dynamic policy designed to select activities to start at each decision time point is illustrated. The performance of static and dynamic policies based on variable neighborhood search is evaluated under the discrete-event simulation environment. Experiments with J120 sets in PSPLIB and several probability distributions of activity duration show that the dynamic policy is superior to static policies. Even when the variability is high, the dynamic policy provides stable and good solutions.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06c
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• pp.517-521
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• 2008

HMM의 약점인 상태 지속 분포를 개선하는 새로운 개념의 확률적 전역+지역 시간 지속 분포 segment 모델(GL-STDM)을 제안한다. 즉, 시계열 신호의 전역적 시간 정보를 표현하고, 각 상태 별 duration 모델과 각 상태의 duration 정보 사이의 상관관계를 표현하는 global pattern (shape 또는 long-term dependency)을 제안한다. 그러나 제안 모델은, Markov 가정을 깨뜨리기 때문에 dynamic programming이 자랑하는 단순함, 효율성을 유지하지는 못한다. 하지만 최근 부각되는 방법인 Monte Carlo 표본 기법을 이용하여 효과적으로 문제를 해결하는 방법을 제시하였다. 본 논문에서는 제안 모델 GL-STDM의 개념과 정의, 그리고 추론 방법과 모델 평가 방법을 기술하였다.

• Phonetics and Speech Sciences
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• v.3 no.3
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• pp.49-56
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• 2011

This study investigates how American English high back vowels are identified. American English and Korean speakers participated in a phonetic experiment for this study. This study shows their response times of the vowels and discusses how the speakers identified them. For the experiment I used a synthesized vowel continuum between American English /u/ and /$\mho$/based on American English male speakers' voice obtained by Peterson and Barney (1952). I manipulated spectral steps and vowel duration of the stimuli. The statistical results showed that American English speakers were not able to distinguish the stimuli based on spectral quality. Instead they relied on vowel duration. This suggests that the American English high back vowels have changed since Peterson and Barney recorded them in 1952. The Korean speakers also relied on vowel duration, not spectral quality since they could not distinguish them. American speakers' response times of these vowels were not affected by both spectral quality and vowel duration. Koreans' response times were affected by vowel durations only.

• Asia pacific journal of information systems
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• v.34 no.1
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• pp.226-247
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• 2024

Most studies on recommender systems to evaluate recommendation performances focus on offline evaluation methods utilizing past customer transaction records. However, evaluating recommendation performance through real-world stimulation becomes challenging. Moreover, such methods cannot evaluate the duration of the recommendation effect. This study measures the personalized recommendation (stimulus) effect when the product recommendation to customers leads to actual purchases and evaluates the duration of the stimulus personalized recommendation effect leading to purchases. The results revealed a 4.58% improvement in recommendation performance in the online environment compared with that in the offline environment. Furthermore, there is little difference in recommendation performance in offline experiments by period, whereas the recommendation performance declines with time in online experiments.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.7 no.1
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• pp.51-66
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• 2001

Objective: The purpose of study was to compare physical therapy duration in relation tohealth care organization system in patients with low back pain. Subjects: Subjects of this study were 759 patients who are receiving physical therapy at 56 health care organization. Methods: Data were collected by questionnaire that had been completed by patients and physical therapist for two months. Physical therapy procedures consisted of modality application, manual therapy, active therapeutic exercise, and patient education. Physical therapy session duration was investigated for each physical therapy procedure. Data were analyzed in relation to the university hospital, hospital, and clinic. Results: The mean age of subjects was $42.84{\pm}15.46$. There were no significant differences in age among three groups. The number of patients diagnosed with herniated disc were 244(32.15%) and with mechanical low back pain was 187(24.64%). The mean treatment duration per day was 53.22 minutes, and the longest treatment duration was 61.28 minutes at the university hospitals (p<0.001). The mean modality application duration was 42.17 minutes, and the longest application duration was 46.26 minutes at the university hospitals (p<0.001). The mean duration for manual therapy was 5.11 minutes, and the longest treatment duration was 5.97 minutes at clinics. The mean duration for active therapeutic exercise was 4.16 minutes. It was 7.60 minutes at the university hospitals, and 2.48 minutes at clinics. There was a significant difference in active therapeutic exercise duration between university hospitals and clinics(p<0.001). For modalities, hot packs(89.33%) and interferential current therapy(60.87%) were mostly applied. For manual therapy, Soft tissue mobilization(32.93%) and manipulation(14.10%) were mostly applied. In general, treatment application duration was longer at University hospital (p<0.05). For therapeutic exercise, exercise without equipment(18.84%) and muscle strengthening (16.73%) were mostly performed. The longest treatment duration for therapeutic exercise was 7.60 minutes at the university hospital(p<0.05). Conclusion: physical therapy session duration for low back pain was 53.22 minutes. Modality application constitutes 79%, manual therapy 10%, active therapeutic exercise 8% of total treatment duration. It is concluded that patients do not participate actively in treatment procedures.

• Journal of Power Electronics
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• v.19 no.2
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• pp.333-343
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• 2019

Dead time and the nonideal characteristics of components all lead to phase voltage distortions. In order to eliminate the harmful effects caused by distortion, numerous methods have been proposed. The efficacy of a method mainly depends on two factors, the compensation voltage amplitude and the phase current polarity. Theoretical derivations and experiments are given to explain that both of these key factors can be deduced from the compensation time, which is defined as the error time between the ideal phase voltage duration and the actual phase voltage duration in one Pulse Width Modulation (PWM) period. Based on this regularity, a novel method for compensating phase voltage has been proposed. A simple circuit is constructed to realize the real-time feedback of the phase voltage. Utilizing the actual phase voltage, the compensation time is calculated online. Then the compensation voltage is derived. Simulation and experimental results show the feasibility and effectivity of the proposed method. They also show that the error voltage is decreased and that the waveform is improved.

• Journal of Physiology & Pathology in Korean Medicine
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• v.35 no.1
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• pp.8-14
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• 2021

Shihogayonggolmoryo-tang (ST) is a Korean medical herb cocktail which has been used to treat anxiety induced insomnia. In this study, we will examine sleep-promoting and anti-anxiety effects of ST, and investigate its mechanism. ICR mice were divided into three groups for the first examination : control group (n=11), ST50 group (50 mg/kg, po, n=11), ST200 group (200 mg/kg, po, n=11). Sleep-promoting effect was confirmed by measuring the sleeping duration time and sleeping onset time after thiopental sodium treatment (50 mg/kg, ip). ICR mice were divided into five groups for the second examination : control group (n=11), ST200 group (200 mg/kg, po, n=11), ST200+Flumazenil group (ST 200 mg/kg, po, flumazenil 0.3 mg/kg, ip, n=11), diazepam group (1 mg/kg, ip, n=11), diazepam+flumazenil group (diazepam 1 mg/kg, ip, Flumazenil 0.3 mg/kg, ip, n=11). Anxiety behavior and sleep-promoting effect was confirmed by open field test and measuring the sleeping duration time and sleeping onset time. Expression levels of c-fos in tuberomammillary nucleus (TMN) and ventrolateral preoptic nucleus (VLPO) were analyzed by immunohistochemistry. ST treated group showed significantly decreased anxiety behavior and enhanced sleeping duration time and sleeping onset time concentration dependently. The expression of c-fos was significantly upregulated in VLPO as sleep-inducing center and TMN as downregulated in arousal center by ST treatment. In addition, all effects of ST were reversed by flumazenil. Our results suggest that ST has sleep-promoting and anti-anxiety effects through regulating arousal center (TMN) and sleep-inducing center (VLPO).

• The Journal of Korean Medicine
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• v.16 no.2 s.30
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• pp.299-311
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• 1995

The studies were investigated in the coma time and the survival time induced by KCN, the duration of breathing after decapitation, the survival time following ligation of both common carotid arteries and the survival time after it is treated for normobaric bypoxia with a nitrogen gas, a carbon dioxide gas or a vaccum in mice. The results were as follows: 1. In histotoxic anoxia, Moschus(0.4mg／kg, p.o) demonstrated a protective effect on coma induced by a sublethal dose of KCN(1.8mg／kg, i.v.) in mice. 2. Mice subjected to a lethal dose of KCN(3.0mg／kg, i.v.) did not die by administration of Moschus. 3. Moschus was significantly extended the duration of breathing after decapitation in mice. 4. Moschus showed a significant extension of survival time in mice following ligation of both common carotid arteries. 5. In the normobaric hypoxia with a nitrogen gas, Moschus showed a significant extension of survival time in mice. 6. In the normobaric hypoxia with a carbon dioxide gas, Moschus showed a significant shortness of survival time in mice. 7. In the normobaric hypoxia with a vaccum, Moschus showed a significant extension of survival time in mice. From the above results, it is suggested that Moschus demonstrated protective effects on the brain damages induced by cerebral anoxia.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.3
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• pp.39-44
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• 2001

In frequency hopping spread spectrum(FHSS) communication systems, exact frequency synchronization is required due to the random hopping of carrier frequencies between transmitter and receiver even under harsh channel conditions. For synchronization of FHSS communications, multi-frequency hopping synchronization(MFHS) method has been used in which a small set of frequencies are repeatedly sent several times for long duration. But this long duration resulted in being easily detected by the unauthorized users as well as long duration of acquisition time. In this paper, motivated by these problems, an adaptive synchronization method(ASM) is proposed. ASM is technics to reduce the synchronization time where the number of synchronization frequencies and repetition numbers is adaptively changed (increased or decreased) according to the channel conditions. The performance analysis showed that the time duration of synchronization was reduced to 0.2sec, and the influence of jamming or interference was decreased to 46% in ASM.