• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.1
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• pp.15-22
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• 2009

Auto-navigation algorithm have been studied to avoid collision and grounding of a ship due to human error. There have been many research on collision avoidance algorithms but they have been validated little on the real coastal traffic situation. In this study, a Collision Avoidance algorithm is developed by using Fuzzy algorithm and the concept of Changeable Action Space Searching (CAS). In the first step, on a basis of collision risk calculated from fuzzy algorithm in the current time(t=to), alternative Action Space for collision avoidance is planned. In the second step, next alternative Action Space for collision avoidance in the future($t=to+{\Delta}t$) is corrected and re-planned with re-evaluated collision risk. In the third step, the safest and most effective course among Action Space is selected by using optimization method in real time. In this paper, the main features of the developed collision avoidance algorithm (CAS) are introduced. CAS is implemented in the ship-handling simulator of MOERI. The performance of CAS is tested on the situation of open sea with 3 traffic ships, whose position is assumed to be informed from AIS. Own-ship is fully autonomously navigated by autopilot including the collision avoidance algorithm, CAS. Experimental results show that own-ship can successfully avoid the collision against traffic ships and the calculated courses from CAS are reasonable.

• The Korean Society of Law and Medicine
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• v.17 no.1
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• pp.139-168
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• 2016

Two alternative dispute resolutions for medical dispute have been operated under the States of German Medical Associations. The first is the medical mediation committee of North german area, the other is the advisory committee on medical errors in North-Rhine area. The former has focused on the mediation itself, the latter commission has focused on the expert review itself whether the physician has maintained reasonable care in diagnosis and treatment. Even though these organizations have maintained under the medical associations, to maintain the neutrality on legal and medical decision, the North German mediation committee is composed of a lawyer and a medicine doctor respectively and North-Rhine advisory committee has a lawyer chair person and four medicine doctors. The main difference of Korean Medical Dispute Mediation Agency in respect from the german system is that expert review is subordinated to the mediation process. The neutrality of expert review is suspected from the medicine doctors. The neytrality and the efficiency should be improved to treat the medical disputes. To do so, lawyer and medicine doctor work together in mediation process and lawyer should manage the expert review process but not involved. Mediation process and expert review should be checked and balanced, and they could be developed as a separated process itself.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.4
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• pp.159-165
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• 1987

This study proposes an operational method of typhoon risk assessments in Korea, using Statistical analysis and probabilistic description of typhoon at a site. Two alternative simulation and fitting methods are discussed to predict the probabilistic typhoon wind speeds by indirect methods. A Commonly used indirect method is Russell's procedure, which generates about 1,000 Simulation data for typhoon winds, statistically evaluate the base-line distribution, and then fits the results to the Weibull distribution based on probabilistic description of climatological Characteristics and Wind field model of typhoon at a site. However, an alternative procedure proposed in this Paper simulates extreme typhoon wind data of about 150~200 years and directly fits the generated data to the Weibull distribution. The computational results show that the proposed simulation method is more economical and reasonable for typhoon risk-assessment based on the indirect method. And using the proposed indirect method, the probabilistic design wind speed for transmission towers in typhoon-prone region along the South-Western coast is investigated.

• Journal of Korean Society of Transportation
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• v.26 no.4
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• pp.17-28
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• 2008

Favorable policies for freight vehicles (i.e., trucks), such as exclusive "Truck-ways," have been proposed, and at the same time restricted policies for freight vehicles have been suggested because transportation of goods by truck aggravates traffic congestion and environmental conditions in urban areas. This study discusses the limitations of assessment processes for freight vehicle route management systems which have been carried out from limited perspectives such as physical distribution efficiency and traffic circulation. The objective of this study is to propose an assessment method of truck route management systems in urban areas which includes more varied criteria. This research modified the two existing assessment indices of physical distribution efficiency and traffic circulation. In addition two new assessment indexes are proposed: (i) exposure indices for population directly influenced by nitrous oxide, a representative pollutant, and (ii) a friction index between trips for attending elementary school and freight vehicle trips. It was found that from the perspective of physical distribution efficiency and traffic circulation, the "before" alternative is better than "after". However, from the aspect of traffic safety and environmental impacts the "after" alternative is better than "before". It is expected that the proposed evaluation method in this study would be useful when identifying reasonable policies for truck route management in urban areas.

• The Korean Journal of Archival Studies
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• no.5
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• pp.3-37
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• 2002

Today the market of EDMS is esteemed more than 100 billions won. It signifies a comming of age of electronic records. The traditional archival theories which are based on the paper records are confronted with a new challenge. In some leading countries of archival studies reorientation of archives management has been tried by a number of distinguished specialists such as Bearman and Hedstrom since 10 years. As a consequence new paradigm of archival theories has been developed. Also in Korea this new paradigm has been introduced by some expert such as Lee, Sang-Min, Sul, Moon-won, Lee, Seung-Eok. However their arguments are too general to offer a concrete clue for new paradigm. Faced by new age of electronic records, it's important to start a discussion for the reasonable methods of electronic records management at once. The most drastically changed part of record management by the electronic technique is the life-cycle of records. The commonly practiced three-stage life-cycle is to be reduced to the two-stage life-cycle, and the concept of the spatial movement of records is to be changed. It can be also pointed that the public emerges as user from the early creating stage of records beyond time and space. Thus is can be said that the method of the management features dynamic and cohesive. The method of appraisal must be also changed and reproduced, so that it can reflect the various levels considering dynamics of the electronic records. Supposedly it will be a core factor that causes the change of methodology in records management with the change of life-cycle theory. It must be noted that various subjects would be involved in the work of classification and description over time and space and that feedback between them is of important. Description also tends to be made at the crating stage of records and structured dynamically. It results from the change of life-cycle and the introduction of the concept of continuum. Such trend allows us to start discussions on the assumption that description of both creator and archival professionals act together an important role. Of course, it is linked with the methodology in which most descriptions are made automatically at the early drafting stage of the structure. The meat date is formed on the assumption that there should be feedback between areas of automatic description, description of creators and archival professionals. The most important thing in description is to develop a suitable way how it is structured. An alternative must be offered for managing data set. As iweb that is being operated by Myongji university shows, records created in daily business are managed not as electronic records but as date base. This is because they exist outside the repository in the EDMS system. Since data set often has various sources, an alternative for classification needs to be developed. It is now likely that database is filed according to the created year to be transferred automatically to the repository. Over a long-term the total management of database, electronic records and electronic information will be a topic. A right direction of new paradigm will be found for both iweb and E-government, when practice and studies of theories are combined and interacted.

• Journal of Korean Neurosurgical Society
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• v.67 no.6
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• pp.646-653
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• 2024

Objective : Microscopic microvascular decompression (MVD) has been considered to be a useful treatment modality for medically refractory hemifacial spasm (HFS) and trigeminal neuralgia. But, the advent of the endoscopic era has presented new possibilities to MVD surgery. While the microscope remains a valuable tool, the endoscope offers several advantages with comparable clinical outcomes. Thus, fully endoscopic MVD (E-MVD) could be a reasonable alternative to microscopic MVD. This paper explores the safety and efficacy of the fully E-MVD technique. Methods : A single-center retrospective study was conducted in 25 patients diagnosed with HFS between September 2019 and July 2023. All surgeries were performed by a single neurosurgeon using the fully E-MVD technique without any assistance of a microscope. The study reviewed intraoperative brainstem auditory evoked potentials and disappearance of the lateral spread response. Outcomes were assessed based on the patients' clinical status immediately after surgery and at their last follow-up. Complications, including facial palsy, hearing loss, ataxia, dysphagia, palsy of other cranial nerves, and cerebrospinal fluid leakage, were also examined. Results : The most common offending artery was the anterior inferior cerebellar artery (AICA) in 15 cases (60.0%), followed by the posterior inferior cerebellar artery in eight cases (32.0%), vertebral artery (VA) in one case (4.0%), tandem lesions involving the AICA and VA in one case (4.0%). Ten patients (40.0%) had pre-operative facial palsy on the ipsilateral side, and eight patients (32.0%) experienced delayed facial palsy on the ipsilateral side, from which they fully recovered by the last follow-up. The median operation time was 105 minutes. All patients were symptom free immediately after surgery and at the last follow-up. One patient experienced a permanent complication, such as high-frequency hearing loss, from which he partially recovered over time. Conclusion : Fully E-MVD demonstrated similar clinical outcomes to microscopic MVD. It offered a similar complication rate, shorter operation time, and a panoramic view with a smaller craniectomy size. Although there is a learning curve associated with fully E-MVD, it presents a viable alternative in the endoscopic era.

• Journal of Soil and Groundwater Environment
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• v.12 no.3
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• pp.10-16
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• 2007

The slug test by adding water to well and measuring falling head was conducted to investigate the hydrogeological property of unsaturated or partially saturated mine tailings in the Imgi abandoned mine in Busan. In case that wells were installed with a full screen through two layers with different hydraulic properties, Bouwer and Rice method was useful to estimate the hydraulic conductivity and the depth of mine tailings. In particular, when groundwater dried out in the dry season, the slug test performed by adding water into well to form artificial water table and then conducting falling head test produced the reasonable hydraulic conductivity values. The slug test using falling head test can be an alternative to investigate the hydrogeological property of abandoned mine tailings.

• Health Policy and Management
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• v.19 no.2
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• pp.21-35
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• 2009

Limited studies examined Medical Aid recipients' perception for amount of medical use. This study aimed to identify self-perception(optimal, under and overutilization) for amount, and real amount of medical use, and to determine factors associated with the perception. Subjects were 2,489 Medical Aid recipients among top 2% overusers in 2005. 200 case managers(CM) managing them conducted survey. CM interviewed them using 2005 medical claiming data from the Health Insurance Review & Assessment Service and structured questionnaire. Despite of overusers, perception of overutilization was only 26.9% and 23.6% in Class I and Class II, and that of underutilization was 21.4% and 18.7% respectively. In Class I, monthly total outpatient cost per capita of overutilization perception in 2006 was 206 thousand won higher than 150 thousand won of optimal utilization. Amounts of outpatient visit-days and prescribed cases of overutilization perception were higher than those of optimal and underutilization(p <0.0001). In Class II, overutilization perception had more prescribed cases(p 0.004). After adjustment of confounding factors including age and sex, the associated factors(odds ratio) with overutilization perception were hypertension(1.25), arthritis(1.32), depression(1.66), visit of multi medical institutions(3.09), and those of the underutilization were female(1.34), disabled(1.27), no family support(1.49), living in medium and small city(1.48), experience of unabled-visit to medical institution(2.54), frequent visit-recommendation from physician (1.36). In conclusion, education and consult are needed for subjects to improve the reasonable decision of medical use, and the self-care ability to manage diseases and symptoms. We suggest reinforcing the alternative service in community instead of costly medical institution.

• Journal of Ecology and Environment
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• v.38 no.4
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• pp.397-403
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• 2015

Rice (Oryza sativa L.) is an important feeding crop in Asia, and utilization of genetically modified (GM) rice is highly demanding. For co-existence of GM rice and non-GM rice, the proper confinement measures should be provided. Thus, we surveyed gene flow from herbicide resistant GM rice to the conventional rice cultivars in the field tests. Gene flow frequency decreased with increasing distance between the pollen donor and recipients and did not exceed more than 1% even at the nearest distance. In single recipient model plot, a maximum gene flow frequency was observed at the shortest distance and hybrid was detected up to 12 m from the pollen donor. The direction of gene was coincided with the dominant wind direction. Gene flow assessment to multiple recipient plots was conducted under the high raining season by chance, and abrupt decline of gene flow frequency and maximum distance were resulted. According to the survey results, current regulation for isolation distance is reasonable for environmental safety or for general crop production. However, we suggest an alternative measure for GM rice cultivation that should be supplemented to overcome the out of estimation and in the environment asking higher security levels.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.2
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• pp.634-645
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• 2014

VoIP (Voice over Internet Protocol) is a technology of transmitting and receiving voice and data over the Internet network. As the telecommunication industry is moving toward All-IP environment with growth of broadband Internet, the technology is becoming more important. Although the early VoIP services failed to gain popularity because of problems such as low QoS (Quality of Service) and inability to receive calls as the phone number could not be assigned, they are currently established as the alternative service to the conventional wired telephone due to low costs and active marketing by carriers. However, VoIP is vulnerable to eavesdropping and DDoS (Distributed Denial of Service) attack due to its nature of using the Internet. To counter the VoIP security threats efficiently, it is necessary to develop the criterion or the model for estimating the information security level of VoIP service providers. In this study, we developed reasonable security indicators through questionnaire study and statistical approach. To achieve this, we made use of 50 items from VoIP security checklists and verified the suitability and validity of the assessed items through Multiple Regression Analysis (MRA) using SPSS 18.0. As a result, we drew 23 indicators and calculate the weight of each indicators using Analytic Hierarchy Process (AHP). The proposed indicators in this study will provide feasible and reliable data to the individual and enterprise VoIP users as well as the reference data for VoIP service providers to establish the information security policy.