• Journal of Korean Neurosurgical Society
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• v.52 no.2
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• pp.114-119
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• 2012

Objective : The purpose of this study was 1) to analyze clinically-executed cervical lateral mass screw fixation by the Kim's technique as suggested in the previous morphometric and cadaveric study and 2) to examine various complications and bicortical purchase that are important for b-one fusion. Methods : A retrospective study was done on the charts, operative records, radiographs, and clinical follow up of thirty-nine patients. One hundred and seventy-eight lateral mass screws were analyzed. The spinal nerve injury, violation of the facet joint, vertebral artery injury, and the bicortical purchases were examined at each lateral mass. Results : All thirty-nine patients received instrumentations with poly axial screws and rod systems, in which one hundred and seventy-eight screws in total. No vertebral artery injury or nerve root injury were observed. Sixteen facet joint violations were observed (9.0%). Bicortical purchases were achieved on one hundred and fifty-six (87.6%). Bone fusion was achieved in all patients. Conclusion : The advantages of the Kim's technique are that it is performed by using given anatomical structures and that the complication rate is as low as those of other known techniques. The Kim's technique can be performed easily and safely without fluoroscopic assistance for the treatment of many cervical diseases.

• Journal of Korean Neurosurgical Society
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• v.48 no.4
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• pp.347-353
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• 2010

Objective : Iliac screw fixation has been used to prevent premature loosening of sacral fixation and to provide more rigid fixation of the sacropelvic unit. We describe our technique for iliac screw placement and review our experience with this technique. Methods : Thirteen consecutive patients who underwent spinopelvic fixation using iliac screws were enrolled. The indications for spinopelvic fixation included long segment fusions for spinal deformity and post-operative flat-back syndrome, symptomatic pseudoarthrosis of previous lumbosacral fusions, high-grade lumbosacral spondylolisthesis, lumbosacral tumors, and sacral fractures. Radiographic outcomes were assessed using plain radiographs, and computed tomographic scans. Clinical outcomes were assessed using the Oswestry Disability Index (ODI) and questionnaire about buttock pain. Results : The median follow-up period was 33 months (range, 13-54 months). Radiographic fusion across the lumbosacral junction was obtained in all 13 patients. The average pre- and post-operative ODI scores were 40.0 and 17.5, respectively. The questionnaire for buttock pain revealed the following : 9 patients (69%) perceived improvement; 3 patients (23%) reported no change; and 1 patient (7.6%) had aggravation of pain. Two patients complained of prominence of the iliac hardware. The complications included one violation of the greater sciatic notch and one deep wound infection. Conclusion : Iliac screw fixation is a safe and valuable technique that provides added structural support to S1 screws in long-segment spinal fusions. Iliac screw fixation is an extensive surgical procedure with potential complications, but high success rates can be achieved when it is performed systematically and in appropriately selected patients.

• Journal of Korean Neurosurgical Society
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• v.48 no.3
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• pp.193-198
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• 2010

Objective : The purpose of this study is to compare the incidence of possible complications of cervical lateral screw fixation and the achievements of bicortical purchase using the Roy-Camille, Magerl and the modified methods. Methods : Six fresh-frozen cervical spine segments were harvested. The Roy-Camille technique was applied to C3 and C4, and the Magerl technique was applied to C5, C6, and C7 of one side of each cadaver. The modified technique was applied to the other side of each cadaver. The nerve root injury, violation of the facet joint, vertebral artery injury, and the bicortication were examined at each screwing level. Results : No vertebral artery injury was observed in any of the three methods. One nerve root injury was observed in each cervical spine segment using the Roy-Camille method (8.3%), the Magerl method (5.6%), and the modified method (3.3%). Facet joint injuries were observed in two cervical spinal segments using the Roy-Camille method (16.7%) and three with the Magerl method (16.7%), while five facet joint violations occurred when using the modified method (16.7%). Bicortical purchases were achieved on ten cervical spinal segments with the Roy-Camille method (83.3%) and Magerl method (55.6%), while twenty bicortical purchases were achieved in the modified method (66.7%). Conclusion : The advantages of the modified method are that it is performed by using given anatomical structures and that the complication rate is as low as those of other known methods. This modified method can be performed easily and safely without fluoroscopic assistance for the treatment of many cervical diseases.

• Journal of Communications and Networks
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• v.11 no.1
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• pp.26-35
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• 2009

In this paper, we investigate how to do resource allocation to guarantee a minimum user data rate at low signaling overhead in multi-cell orthogonal frequency division multiple access (OFDMA) wireless systems. We devise dynamic resource allocation (DRA) algorithms that can minimize the QoS violation ratio (i.e., the ratio of the number of users who fail to get the requested data rate to the total number of users in the overall network). We assume an OFDMA system that allows dynamic control of frequency reuse factor (FRF) of each sub-carrier. The proposed DRA algorithms determine the FRFs of the sub-carriers and allocate them to the users adaptively based on inter-cell interference and load distribution. In order to reduce the signaling overhead, we adopt a hierarchical resource allocation architecture which divides the resource allocation decision into the inter-cell coordinator (ICC) and the base station (BS) levels. We limit the information available at the ICC only to the load of each cell, that is, the total number of sub-carriers required for supporting the data rate requirement of all the users. We then present the DRA with limited coordination (DRA-LC) algorithm where the ICC performs load-adaptive inter-cell resource allocation with the limited information while the BS performs intra-cell resource allocation with full information about its own cell. For performance comparison, we design a centralized algorithm called DRA with full coordination (DRA-FC). Simulation results reveal that the DRA-LC algorithm can perform close to the DRA-FC algorithm at very low signaling overhead. In addition, it turns out to improve the QoS performance of the cell-boundary users, and achieve a better fairness among neighboring cells under non-uniform load distribution.

• KIPS Transactions on Software and Data Engineering
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• v.5 no.12
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• pp.615-622
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• 2016

Automotive control software can be a source of critical safety issues when developers do not comply system constraints. However, a violation is difficult to identify in complicated source code if not supported by an automated verification tool. This paper introduces two possible approaches that check whether an automotive control software complies API call constraints to compare their performance and effectiveness. One method statically analyzes the source code and explores all possible execution paths, and the other utilizes a model checker to monitor constraint violations for a given set of constraint automata. We have implemented both approaches and performed a series of experiments showing that the approach with model-checking finds constraint violations more accurately and scales better.

• Journal of Convergence Society for SMB
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• v.5 no.3
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• pp.27-31
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• 2015

As the number of smartphone users is increasing with the development of mobile devices, the range of monetary transaction from the individual use is increasing. Therefore, hacking methods are diversified and the information forgery of mobile devices has been a current issue. The forgery via apps in mobile devices is a hacking method that creates an app similar to well-known apps to deceive the users. The forgery attack corresponds to the violation of integrity, one of three elements of security. Due to the forgery, the value and credibility of an app decreases with the risk increased. With the forgery in app, private information and data can be stolen and the financial losses can occur. This paper examined the forgery, and suggested a way to detect it, and sought the countermeasure to the forgery.

• Journal of Sasang Constitutional Medicine
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• v.22 no.2
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• pp.1-15
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• 2010

1. Objectives: This research aims to study the general overview of the theories on the covetous desire and the relevant theories on cultivation mentioned in "Donguisusebowon (東醫壽世保元): Theories on Nature and Conduct (性命論)". 2. Methods: The theories concerning the covetous desire introduced in Dong-Mu's manuscripts, including "Gyukchigo 格致藁)", "Yougocho (遺稿抄)", "Dongmuyougo (東武遺稿)" and "Jaejungsinpyun (濟衆新編)", were comprehensively reviewed. Furthermore, the significance of the theories on the covetous desire and the relevant theories on self-cultivation were studied within the context of "Donguisusebowon(東醫壽世保元): Theories on Nature and Conduct (性命論)". 3. Results and Conclusions: 1) Among the four covetous desires (selfishness (私心), indiscretion (放心), indolence(逸心), acquisitiveness (慾心)), selfishness and acquisitiveness are the interpersonal components that deal with the relationship between individuals, whereas indiscretion and indolence are the intra-personal or self-concerned components that deal with the internal desires within the individual. 2) In the early concepts on the quaternity explaining the perspective on the human being as introduced in Dongmu's earlier manuscripts, the four covetous desires are thought of as the most important etiological components, that are also intimately related to the theories of self-cultivation. 3) Among the concepts introduced in "Donguisusebowon (東醫壽世保元): Theories on Nature and Conduct (性命論)", viciousness (邪心) and negligence (怠心) are primary, intra-personal (self-concerned) desires that are henceforth matched to indiscretion and indolence, respectively, while selfishness (arrogance, assertiveness, indiscrimination and exaggeration (驕矜伐夸)) and acquisitiveness (violation, extravagance, slothfulness and stealthiness(奪侈懶竊)) are secondary, interpersonal desires. 4) 'Preserving the mind (存其心)' and 'rectifying the body (修其身)' are Methods of overcoming viciousness (indiscretion) and negligence (indolence), the intrapersonal desires, while 'nurturing the nature (養其性)' and 'propping the course (立其命)' are Methods of eliminating selfishness and acquisitiveness, the interpersonal desires, which ultimately each leads to the completion of Nature (性) and Conduct/Course (命).

• Journal of Trauma and Injury
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• v.28 no.4
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• pp.262-265
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• 2015

An arteriovenous fistula (AVF) from the renal artery following a penetrating abdominal trauma is not common. We report the case of a 19-year-old male who presented with a knife stab wound in the right upper quadrant. Due to unstable vital signs and to the protrusion of the mesentery through the stab wound, providing definite evidence of peritoneal violation, an emergent exploratory laparotomy was carried out. There were injuries at the proximal transverse mesocolon and the second portion of the duodenum, with bile leakage. There was also a mild amount of retroperitoneal hematoma near the right kidney, without signs of expansion or pulsation. The mesocolon and the duodenum were repaired. After the operation, abdominal computerized tomography (CT) was performed, which revealed contrast from the right renal artery shunting directly into the vena cava. Transcatheter arterial embolization with a coil and vascular plug was performed, and the fistula was repaired. The patient recovered completely and was discharged without complication. For further and thorough evaluation of an abdominal trauma, especially one involving the retroperitoneum, a CT scan is recommended, when possible, either prior to surgery or after surgery when the patient is stabile. Furthermore, a lateral retroperitoneal hematoma and an AVF after a penetrating trauma may not always require exploration. Sometimes, it may be safely treated non-operatively or with embolization.

• Proceedings of the KOR-KST Conference
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• 2007.11a
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• pp.574-583
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• 2007

The quality of service on urban roadways have been evaluated mainly based on such quantitative measures as travel speed and delay. However, in addition to the quantitative aspects, drivers traveling on urban roadways are subject to be influenced by qualitative measures such as aesthetic aspects of the roadway and other drivers' violation of traffic laws. Based on this notion, this study attempts to identify roadway service quality indices, considering both qualitative and quantitative aspects and evaluate the quality of service using the modified Importance-Performance Analysis (IPA), a technique often applied in the field of marketing. The modified IPA is proposed in this study as a way to evaluate the service quality, reflecting the relative performance between study areas and performance indices. A case study is implemented over the Gangnam and Gangbuk areas in Seoul, resulting in identifying the items needed to be improved for each study area.

• Journal of Arbitration Studies
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• v.22 no.2
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• pp.103-124
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• 2012

Because the Korea-U.S. Free Trade Agreement (Korea-U.S. FTA) and the North American Free Trade Agreement (NAFTA) have an overlapping contracting party, the United States, their provisions have much in common. The investment chapters of these agreements, especially, show many similarities, and thanks to these similarities, it is likely that the Korea-U.S. FTA arbitration tribunal for investor-state disputes regarding the environment will put great weight on the NAFTA tribunals' interpretations of those similar provisions. Since the NAFTA tribunals have already handled many environment-related arbitration cases, their interpretations will help heighten the predictability of environment-related Korea-U.S. FTA arbitration cases. This paper analyzes the environment-related NAFTA cases in which the tribunal has issued an award, which are the Metalclad case, S.D. Myers case, Waste Management case, Methanex case, Glamis Gold case, and Chemtura case. According to this analysis, the most controversial NAFTA provisions have been Article 1102 (national treatment), Article 1105 (minimum treatment standard, fair and equitable treatment), and Article 1110 (expropriation). The NAFTA tribunals applied the requirement of these articles in a strict manner, reducing the possibility of finding a violation. After the aforementioned analysis, this paper proceeds to compare the national treatment, minimum treatment standard (fair and equitable treatment), and expropriation provisions of the Korea-U.S. FTA and NAFTA and to predict the impact that the environment-related awards under NAFTA can have on environment-related Korea-U.S. FTA cases. It is expected that the NAFTA interpretations of the national treatment and minimum treatment provisions are likely be used as they are, but not the interpretations of expropriation, because of the differences in the expropriation provisions of the two agreements.