• The Korean Journal of Pain
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• v.25 no.2
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• pp.94-98
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• 2012

Background: An intravenous infusion of lidocaine has been used on numerous occasions to produce analgesia in neuropathic pain. In the cases of failed back surgery syndrom, the pain generated as result of abnormal impulse from the dorsal root ganglion and spinal cord, for instance as a result of nerve injury may be particularly sensitive to lidocaine. The aim of the present study was to identify the effects of IV lidocaine on neuropathic pain items of FBSS. Methods: The study was a randomized, prospective, double-blinded, crossover study involving eighteen patients with failed back surgery syndrome. The treatments were: 0.9% normal saline, lidocaine 1 mg/kg in 500 ml normal saline, and lidocaine 5 mg/kg in 500 ml normal saline over 60 minutes. The patients underwent infusions on three different appointments, at least two weeks apart. Thus all patients received all 3 treatments. Pain measurement was taken by visual analogue scale (VAS), and neuropathic pain questionnaire. Results: Both lidocaine (1 mg/kg, 5 mg/kg) and placebo significantly reduced the intense, sharp, hot, dull, cold, sensitivity, itchy, unpleasant, deep and superficial of pain. The amount of change was not significantly different among either of the lidocaine and placebo, or among the lidocaine treatments themselves, for any of the pain responses, except sharp, dull, cold, unpleasant, and deep pain. And VAS was decreased during infusion in all 3 group and there were no difference among groups. Conclusions: This study shows that 1 mg/kg, or 5 mg/kg of IV lidocaine, and palcebo was effective in patients with neuropathic pain attributable to FBSS, but effect of licoaine did not differ from placebo saline.

• ETRI Journal
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• v.34 no.3
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• pp.297-307
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• 2012

A femtocell is a small cellular base station, typically designed for use in a home or small business. The random deployment of a femtocell has a critical effect on the performance of a macrocell network due to co-channel interference. Utilizing the advantage of a multiple-input multiple-output system, each femto base station (FBS) is able to form a cluster and generates a precoding matrix, which is a modified version of conventional single-cell block diagonalization, in a cooperative manner. Since interference from clustered-FBSs located at the nearby macro user equipment (MUE) is the dominant interference contributor to the coexisting networks, each cluster generates a precoding matrix considering the effects of interference on nearby MUEs. Through simulation, we verify that the proposed algorithm shows better performance respective to both MUE and femto user equipment, in terms of capacity.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.10
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• pp.1236-1239
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• 2016

In this paper, we propose a new incentive mechanism for hybrid access in cognitive femtocell networks. The purpose of the proposed incentive mechanism is to guarantee the QoS of macro user equipments (MUEs) and to increase femtocell capacity. MUEs channel condition report triggers bidding procedure by neighbor femtocell base stations (FBS). Macro base station (MBS) can offer some subchannels as rewards to encourage FBSs to reliably support its MUEs. Simulation results validate the effectiveness of our proposed scheme.

• The Korean Journal of Pain
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• v.26 no.2
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• pp.199-202
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• 2013

Epiduroscopic laser discectomy and neural decompression (ELND) is known as an effective treatment for intractable lumbar pain and radiating pain which develop after lumbar surgery, as well as for herniation of the intervertebral disk and spinal stenosis. However, various complications occur due to the invasiveness of this procedure and epidural adhesion, and rarely, cranial nerve damage can occur due to increased intracranial pressure. Here, the authors report case in which double vision occurred after epiduroscopic laser discectomy and neural decompression in a patient with failed back surgery syndrome (FBSS).

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.1
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• pp.47-58
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• 2018

The heterogeneous cellular network (HCN) is most significant as a key technology for future fifth generation (5G) wireless networks. The heterogeneous network considered consists of randomly macrocell base stations (MBSs) overlaid with femtocell base stations (BSs). The stochastic geometry has been shown to be a very powerful tool to model, analyze, and design networks with random topologies such as wireless ad hoc, sensor networks, and multi- tier cellular networks. The HCNs can be energy-efficiently designed by deploying various BSs belonging to different networks, which has drawn significant attention to one of the technologies for future 5G wireless networks. In this paper, we propose switching off/on systems enabling the BSs in the cellular networks to efficiently consume the power by introducing active/sleep modes, which is able to reduce the interference and power consumption in the MBSs and FBSs on an individual basis as well as improve the energy efficiency of the cellular networks. We formulate the minimization of the power onsumption for the MBSs and FBSs as well as an optimization problem to maximize the energy efficiency subject to throughput outage constraints, which can be solved the Karush Kuhn Tucker (KKT) conditions according to the femto tier BS density. We also formulate and compare the coverage probability and the energy efficiency in HCNs scenarios with and without coordinated multi-point (CoMP) to avoid coverage holes.

• The Korean Journal of Pain
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• v.18 no.2
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• pp.214-217
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• 2005

Spinal cord stimulation (SCS) was first attempted by Shearly et al for the relief of intractable pain. A spinal cord stimulator has traditionally been used for failed back surgery syndrome (FBSS) angina pectoris, complex regional pain syndrome (CRPS) and ischemic pain in the extremity. However, the complications associated with the use of a spinal cord stimulator, such as wound infection, hematoma, lead migration and device malfunction; make its long term application difficult. Here, our experience of an interesting case, in which intractable right leg pain was controlled using a spinal cord stimulator placed in the left epidural space, is reported, with a review of the literature.

• Asian Journal of Business Environment
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• v.10 no.2
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• pp.23-31
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• 2020

Purpose: The purpose of this paper is to find out the impact of financial leverage on firm's profitability in the listed textile sector of Bangladesh. Research design, data and methodology: A sample of 22 DSE listed textile firms has been used to conduct the study. In this study, firm profitability is measured by Return on Equity (ROE) and both short term debt and long term debt are used as the as proxies of financial leverage. Pooled Ordinary Least Squares (OLS), Fixed Effect (FE), and Generalized Method of Moments (GMM) models have been used to test the relationship between financial leverage and profitability of firms. Result: This study finds a significant negative relationship between leverage and firm's profitability using the Pooled OLS method. The result is also consistent with the fixed effect and GMM method. This result implies that firm's profitability is negatively affected by the firm's capital structure. Conclusion: The study concludes that maximum textile firms use external debt as a source of finance as they don't have sufficient internally generated funds. This study recommends that firm should give more emphasize on generating fund internally to meet up their financing needs.

• The Korean Journal of Pain
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• v.31 no.4
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• pp.296-304
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• 2018

Epiduroscopy is defined as a percutaneous, minimally invasive endoscopic investigation of the epidural space. Periduroscopy is currently used mainly as a diagnostic tool to directly visualize epidural adhesions in patients with failed back surgery syndrome (FBSS), and as a therapeutic action in patients with low back pain by accurately administering drugs, releasing inflammation, washing the epidural space, and mechanically releasing the scars displayed. Considering epiduroscopy a minimally invasive technique should not lead to underestimating its potential complications. The purpose of this review is to summarize and explain the mechanisms of the side effects strictly related to the technique itself, leaving aside complications considered typical for any kind of extradural procedure (e.g. adverse reactions due to the administration of drugs or bleeding) and not fitting the usual concept of epiduroscopy for which the data on its real usefulness are still lacking. The most frequent complications and side effects of epiduroscopy can be summarized as non-persistent post-procedural low back and/or leg discomfort/pain, transient neurological symptoms (headache, hearing impairment, paresthesia), dural puncture with or without post dural puncture headache (PDPH), post-procedural visual impairment with retinal hemorrhage, encephalopathy resulting in rhabdomyolysis due to a dural tear, intradural cyst, as well as neurogenic bladder and seizures. We also report for first time, to our knowledge, a case of symptomatic pneumocephalus after epiduroscopy, and try to explain the reason for this event and the precautions to avoid this complication.

• The Korean Journal of Pain
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• v.27 no.1
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• pp.63-67
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• 2014

Background: Epiduroscopic laser neural decompression (ELND) has been performed as a treatment tool for chronic refractory low back pain and/or radicular pain. There are some studies about the usefulness of epiduroscopy for post lumbar surgery syndrome, however, few studies about the effectiveness of epiduroscopy for patients without back surgery. We compared the satisfaction of patients who underwent ELND for chronic low back pain and/or radicular pain after back surgery and for the same symptoms without surgery. Methods: We compared the degree of satisfaction of patients after ELND between who had underwent the lumbar spine surgery and who had not retrospectively by chart reviewing. We divided 39 patients who had received ELND into two groups, one is the group of patients who got the lumbar surgery (group 1), and the other is the group of patients who did not (group 2). Their medical records including age, sex, previous treatment, duration of illness, degree of symptom relief were investigated. We compared each items between two groups. Results: The number of patients in group 1 was 17, and group 2 was 22. In group 1, 16 patients (94.1%) showed more than 'Acceptable', and 19 patients (86.4%) showed more than 'Acceptable' in group 2. There is no significant differences statistically in percentage of patients who showed more than 'Acceptable' in the satisfaction after ELND between two groups. Conclusions: ELND provided satisfaction (more than 85%) for patients with chronic low back pain and/or leg pain regardless of previous back surgery history.