• IE interfaces
• /
• v.18 no.3
• /
• pp.327-332
• /
• 2005

The call-attempt behavior in a telecommunications service is influenced by the launch of new services and the choice of subscribers. On Feb 28, 2005, there was a disastrous shut-down of major local electronic switching systems (ESS) due to an abrupt increase of call-attempts. This incident turned out to be a strong proof that appropriate forecasting attempts are necessary not only for the capacity planning of network but also for the quality control of ESS. In this paper, forecasting models are first developed to estimate the daily ESS call-attempts and user retrial rates and then meaningful interpretations of results will follow. Finally future research topics will be presented.

• Journal of the Institute of Convergence Signal Processing
• /
• v.1 no.2
• /
• pp.122-130
• /
• 2000

This paper mainly deals with the modified version of conventional PRMA(Packet Reservation Multiple Access). In the existing PRMA schemes, the occupied slot in the initial access state is not allowed to be reserved in the silent period and retrial of gaining the slot access has to pay additional packet dropping. Whereas in the modified model, we propose to utilize a control minislot that maintains slot reservation and this prevents additional packet drop occurrence since initial access, and this slightly improves the system performance.

• ETRI Journal
• /
• v.44 no.2
• /
• pp.274-285
• /
• 2022

Retransmission in optical burst switching networks is a solution to recover data loss by retransmitting the dropped burst. The ingress node temporarily stores a copy of the complete burst and sends it each time it receives a retransmission request from the core node. Some retransmission schemes have been suggested, but uncontrolled retransmission often increases the network load, consumes more bandwidth, and consequently, increases the probability of contention. Controlled retransmission is therefore essential. This paper proposes a new controlled retransmission scheme for loss recovery, where the available bandwidth of wavelength channels and the burst lifetime are referred to as network conditions to determine whether to transmit a dropped burst. A retrial queue-based analysis model is also constructed to validate the proposed retransmission scheme. The simulation and analysis results show that the controlled retransmission scheme is more efficient than the previously suggested schemes regarding byte loss probability, successful retransmission rate, and network throughput.

• Journal of Arbitration Studies
• /
• v.27 no.4
• /
• pp.3-33
• /
• 2017

This paper examines some questions and issues of the effect of an arbitral award, and discusses about the restriction of the trial level in other separate actions permitted under the existence of grounds of setting aside arbitral award after the amendment of the Arbitration Act in 2016. Because there are no interests of litigation in the action for setting aside arbitral award due to the exclusion of res judicata by provisory clause of Article 35, filing an action for setting aside is not allowed even when the grounds of setting aside exist. If we examine the precedent on possibility of retrial for excluding the outward form of invalid judgement, we can find that the court did not approve the retrial. Therefore, the action for setting aside that which is for excluding the outward form of an arbitral award will not be allowed for filing. On the issue of whether an arbitral award having a ground for setting aside can be an object of the action for setting aside for excluding its outward form or not, the views of scholars are divided. In the case of an arbitral award that has grounds for setting aside, it could be interpreted that the arbitral award would not have a formale Rechtskraft or effect of sentence (bindende Kraft). Even if there is formale Rechtskraft or effect of sentence (bindende Kraft), the significance of existence of action for setting aside arbitral award under paragraph 1 of Article 36 is reduced because other actions separate from arbitration is permitted under the 2016 Act. The amendment of the Arbitration Act in 2016 provides an opportunity to review the position and the role of action for setting aside the arbitral award. It also requires further studies on efficiently treating other actions separate from arbitration. Because the restriction of the trial level of other separate actions can make arbitration active by making arbitration procedures become 3 trial levels from 4 trial levels, it needs to be solved with legislative action. Specifically, if the trial starts at the stage of trial on appeal, it can utilize the strength of both the arbitration and the litigation, playing a chief role in boosting arbitration by removing the problems of action for setting aside and enabling arbitration institutes and the person interested to promote the activation of arbitration.

• Journal of Korean Neurosurgical Society
• /
• v.45 no.6
• /
• pp.378-380
• /
• 2009

Osteoporotic patients who undergo percutaneous vertebroplasty (PVP) have the risk of a repeated collapse of their adjacent vertebral body due to alteration of load transfer into the adjacent vertebral body. The authors have experienced a rare case of repeated osteoporotic vertebral compression fractures (VCF) resulting in extreme multi-level PVP. A 74-year-old female developed severe back pain after slipping down one month ago. Her X-ray and MR images indicated a T11 VCF. She underwent successful PVP with polymethylmethacrylate (PMMA). Two weeks later, she returned to our hospital due to a similar back pain. Repeated X-ray and MR images showed an adjacent VCF on T12. A retrial of PVP was performed on T12, which provided immediate pain relief. Since then, repeated collapses of the vertebral body occurred 12 times in 13 levels within a 24-month period. Each time the woman was admitted to our hospital, she was diagnosed of newly developed VCFs and underwent repeated PVPs with PMMA, which finally eased back pain. Based on our experience with this patient, repeated multiple PVP is not dangerous because its few and minor complications. Therefore, repeated PVP can serve as an effective treatment modality for extreme-multi level VCFs.

• Tuberculosis and Respiratory Diseases
• /
• v.75 no.6
• /
• pp.256-259
• /
• 2013

Imatinib mesylate is a targeted therapy that acts by inhibiting tyrosine kinase of the bcr-abl fusion oncoprotein, which is specific to chronic myeloid leukemia (CML), and the c-transmembrane receptor, which is specific to gastrointestinal stromal tumors. Interstitial pneumonitis is a rare adverse event of imatinib therapy. It is clinically difficult to distinguish from infectious pneumonia, which can frequently occur due to the underlying disease. The standard treatment for imatinib-induced pneumonitis is to discontinue the medication and optionally administer corticosteroids. However, there are a few cases of successful retrial with imatinib. We describe a case of successful rechallenge of imatinib in a patient with imatinib-induced interstitial pneumonitis and CML without a recurrence of the underlying disease after 3 months of follow-up.

• The Transactions of the Korea Information Processing Society
• /
• v.3 no.5
• /
• pp.1093-1102
• /
• 1996

For the reuse, configuration management, and version control of softwares, the composition of retrieval systems and library are most important matters, which makes it possible to retrieve the concerned software components. Retrieval systems, which is able to store many components, must make it possible to retrieve the concerned components with deadwoods in the fastest way. Based either on keyboards or the concept of inverted file on the part of content is usually used in the current retrieval systems. However, in this paper, new retrieval systems are suggested with using set and bag class with Smalltalk language, one of object- oriented programming language, based either on the keywords or on the part of content to find out the concerned components. This method is improved the function of user interface and its management, In this paper, library is also suggested along with the new retrieval systems, and user interface is designed and implemented for its management and control. The new retrial systems of this paper can be employed by interface in another language, and this system is to provide the concerned user with the appropriate retrieval systems and library for the version control.

• Journal of Korean Neurosurgical Society
• /
• v.47 no.4
• /
• pp.278-281
• /
• 2010

Objective : For the treatment of osteoporotic vertebral compression fracture, percutaneous vertebroplasty (PVP) is currently widely used as an effective and relatively safe procedure. However, some patients do not experience pain relief after PVP. We performed several additional PVP procedures in those patients who did not have any improvement of pain after their initial PVP and we obtained good results. Our purpose is to demonstrate the effective results of an additional PVP procedure at the same previously treated level. Methods : We reviewed the medical records and the radiologic data of the PVP procedures that were performed at our hospital from November 2005 to May 2008 to determine the patients who had undergone additional PVP. We identified ten patients and we measured the clinical outcomes according to the visual analogue scale (VAS) score and the radiologic parameters, including the anterior body height and the kyphotic angulation. Results : The mean volume of polymethylmethacrylate injected into each vertebrae was 4.3 mL (range: 2-8 mL). The mean VAS score was reduced from 8 to 2.32. The anterior body height was increased from 1.7 cm to 2.32 cm. The kyphotic angulation was restored from 10.14 degrees to 2.32 degrees. There were no complications noted. Conclusion : The clinical and radiologic outcomes suggest that additional PVP is effective for relieving pain and restoring the vertebral body in patients who have unrelieved pain after their initial PVP. Our study demonstrates that additional PVP performed at the previously-treated vertebral levels could provide therapeutic benefit.

• Tuberculosis and Respiratory Diseases
• /
• v.41 no.4
• /
• pp.372-378
• /
• 1994

Background: Pressure support ventilation(PSV) is a new form of mechanical ventilatory support that assists spontaneous inspiraory effort of an intubated patient with a clinician-selected amount of positive airway pressure. Low level pressure support during inspiration can overcome the resistive component of inspiratory work imposed by an endotracheal tube. However the clinical efficacy of PSV as a weaning method has not been established yet. Object: The aim of study was to evaluate the efficacy of PSV when it is added to intermittent mandatory ventilation(IMV) in facilitating weaning precess compaired to IMV mode alone. Method: When the subject patients became clinically stable with their arterial blood gas analysis in acceptable range, they underwent weaning process either by IMV alone or by IMV plus PSV. The level of pressure support was held constant throught the weaning period. For the patients who required mechanical ventilation for less than 72 hr, 2h weaning trial was performed with IMV rate starting from 6/min. For the patients who required mechanical ventilation more than 72 hr, 7 hr weaning trial was performed with IMV rate starting from 8/min. For the patients who failed three consecutive trials of weaning, retrial of weaning was attempted over 3 days with IMV rate starting from 8/min. Clinical characteristics, APACHE II score and nutritional status were compared. For all patients, heart rate, mean blood pressure and respiratory rate were mornitored for 48 hrs after weaning trial started. Results: The total number of weaning trial was 37 in 23 patients(18 by IMV, 19 by IMV+PSV). Total ventilation time, APACHE II score and nutritional status were not statistically different between the two groups. The weaning success rate were not statistically different(38.3% by IMV, 42.1% by IMV+PSV) and the changes of mean blood pressure, heart rate, respiratory rate during first 48 hours were not different between the two groups. Conclusion: Low level PSV when added to IMV for weaning trial does not seem to improve the success rate of weaning from mechanical ventilation. PSV at 10cm $H_2O$ did not induce significant physiologic changes during weaning process.

• Tuberculosis and Respiratory Diseases
• /
• v.43 no.6
• /
• pp.852-861
• /
• 1996

Background : Many clinicians have experienced the difficulty of decision on termination of antituberculosis chemotherapy after the 6th month due to relapse of disease. There is still controversy in the effect of 2S(K)HRZ/4HRZ 6-month short course chemotherapy including pyrazinamide for 6 months in patiems with pulmonary tuberculosis. And there is no long term follow-up study of 6-month short course chemotherapy for pulmonary tuberculosis in korea. So we had performed the study to find the result of 6-month antituberculosis chemotherapy for 4 years. Method : We studied prospectively the effect of 2S(K)HRZ/4HRZ in one hundred-fifty patients with pulmonary tuberculosis and followed up fifty-nine patients for more than 1 year to 4 years after the completion of 6-month short course therapy. Results : 1) Out of one hundred-fifty patients, seventy-two patients(48%) completed the prescribed 6-month chemotherapy. Sixty-eight patients(45.3%) have experienced premature discontinuation and the most common cause of premature discontinuation was drop-out against advice(thirty-six patients, 24%). Ten patients(6.7%) were treated beyond the 6 months mainly due to irregular treatment. 2) Fifty-nine patients(81.9%) among seventy-two patients with completed treatment have been followed up for more than 1 year and 32 patients(44.4%) for more than 4 years. There was three relapse patients of whom two patients have experienced relapse of pulmonary tuberculosis within 1 year after the termination of chemotherapy. 3) Among one hundred-thirty-four patients who have been assessible for more than two months of chemotherapy, including the patients who experienced within 2 months, there were eighty-two patients(61.2%) who have experienced adverse reactions and the treatment regimen was changed only in thirteen patients(9.7%). The most frequent cause of adverse reactions was arthralgia and/or hyperuricemia, which had occurred in 33 patients(24.6%). Conclusion : In a university hospital in Korea, 6-month shot course chemotherapy of 2S(K)HRZ/4HRZ had unnegligible relapses and premature discontinuation. Therefore, change of the regimen might be carefully considered by drug susceptibility results. Close monitoring of patients, retrial of sputum exam and radiologic evaluation during treatment might be required in the endemic area of drug resistant strains like in Korea. Further study about the effect of 6-month short course chemotherapy including pyrazinamide for 6-month might be needed.