• The korean journal of orthodontics
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• v.28 no.4 s.69
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• pp.547-561
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• 1998

Obstructive sleep apnea (OSA) is a disorder characterized by repetitive episode of upper airway collapse during sleep. Recent studies showed that not only the anatomic factors but the physiologic factors of the upper airway also have effcts on the occurrence of apnea and that the genioglossus muscle also plays an important role in the maintenance of the upper airway. A variety of therapies were performed to treat OSA, and among them the use of mandibular repositioning appliances showed reasonable results. But there is still a lack of research on the structural and physiological mechanism upon the use of mandibular repositioning appliances. The author selected 26(male 17, female 9) OSA patients that came to the Yonsei University Dental Hospital, Department of Orthodontics, and 20 normal adults (male 10, female 10) and took cephalometric radiographs of them in a supine position before and after the placement of the mandibular repositioning appliance to see the structural changes of the upper airway and compare the therapeutic effects between the two groups. We also studied the waking genioglossus muscle activity in OSA patients and investigated the difference in the electromyogram of the genioglosssus muscle upon the change in body posture and the use of mandibular repositioning appliance. Following results were obtained. 1. Among the cephalometric measurements of the upper airway structure, the length of the soft palate, maximum thickness of the soft Palate and SPAS, MAS, VAL, H-H1, MP-H showed statistically significant differences between the normal and OSA groups, but the IAS and EAS showed no statistically significant differences between the two groups. 2. In both the normal and OSA groups, as the epiglottis moved forward on wearing the mandibular repositioning appliance, the epiglottis level of the upper airway increased and the maximum thickness of the soft palate changed and the hyoid bone also moved forward, but the IAS in both groups showed various results and the effect of the mandibular repositioning appliance on the structure of the upper airway was different in the two groups. 3. Upon changing the position, the electromyogram of the genioglossus muscle showed a increasing tendency but there was no statistically significant differences, and when the mandibular repositioning appliance were worn there was a statistically significant increase in the electromyogram of the genioglossus muscle in both the upright and supine positions. The mandibular repositioning appliances not only have an effect on the anatomical structure of the upper airway but also on the physiology of the upper airway. There are different responses to the use of mandibular repositioning appliance between the normal and OSA groups therefore it could be considered to have the different physiology of the upper airway between the two groups.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.2
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• pp.184-199
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• 1996

The challenges to achieve three dimensional facial proportionality and occusal stability in many patients with complex dentofacial deformity have been met by the development and use of the maxilla, mandible, and chin surgery techniques in combination with efficient orthodontic treatment. There is a clinical, biological, and biomechanical foundation for simultaneous surgical repositioning of the maxilla, mandible, and chin in a significant proportion of adult and adolescent patients. A combination of the surgical and orthodontic approach may provide increased treatment efficiencies and optimal esthetic results. Art and science to determine the treatment objectives, specifically, the desired soft tissue changes are firstly established by using the clinician's "esthetic sense" of the facial beauty and proportion aided to a few cephalometric guidelines. In this sense, the dependence on the clinician's "esthetic eye" by Dr. Bell is more important in analyzing the facial proportion than the satisfaction of rigid cephalometric norms. The purpose of this article was to elucidate the indication for simultaneous surgical repositioning of the maxilla, mandible, and chin, and to describe the clinical cephalometric analysis for orthognathic surgery. Representative 6 case reports were presented and discussed to illustrate the esthetic, orthodontic, and surgical treatment objectives with long-term follow-up.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.2
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• pp.36-42
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• 2021

This paper deals with a vehicle routing problem with resource repositioning (VRPRR) which is a variation of well-known vehicle routing problem with pickup and delivery (VRPPD). VRPRR in which static repositioning of public bikes is a representative case, can be defined as a multi-objective optimization problem aiming at minimizing both transportation cost and the amount of unmet demand. To obtain Pareto sets for the problem, famous multi-objective optimization algorithms such as Strength Pareto Evolutionary Algorithm 2 (SPEA2) can be applied. In addition, a linear combination of two objective functions with weights can be exploited to generate Pareto sets. By varying weight values in the combined single objective function, a set of solutions is created. Experiments accomplished with a standard benchmark problem sets show that Variable Neighborhood Search (VNS) applied to solve a number of single objective function outperforms SPEA2. All generated solutions from SPEA2 are completely dominated by a set of VNS solutions. It seems that local optimization technique inherent in VNS makes it possible to generate near optimal solutions for the single objective function. Also, it shows that trade-off between the number of solutions in Pareto set and the computation time should be considered to obtain good solutions effectively in case of linearly combined single objective function.

• Journal of The Korean Society of Integrative Medicine
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• v.5 no.2
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• pp.11-17
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• 2017

Purpose : The aim of this study was to verify differences in cervicocephalic joint position sense error after different sustained sitting postures in healthy young adults. Methods : Twenty-five healthy adults(12 men, 13 women) participated in this study. Repositioning errors of neck movement were observed in participants during joint repositioning tasks. During 2 test days with a 1-week interval, the participants performed forward head posture and upright sitting posture in random order. Both head-to-neutral(HTN) and head-to-target(HTT) tasks were performed on each day. On the first day, the participants sat slouched or upright for 10 minutes. Then, they sat upright and moved their heads at a self-selected speed with their eyes-closed to pre-determined neutral and target positions as accurately as possible. The participants noticed that when they reached a pre-determined position, the errors between pre-determined neutral and target positions and current position was recorded. The tasks consisted of flexion, extension and lateral bending. On the second day, the same test was performed after another sitting posture for 10 minutes. Repositioning error values were collected by using a smart phone-based inclinometer. The mean value for three trials was used for data analysis. A paired t-test was used for statistical analysis. Results : Significant differences in joint repositioning errors were found between the repositioning error after different sitting postures on the sagittal plane for both the HTN and HTT tasks (P<.05). No significant differences in errors on the coronal plane were found (P>.05). Conclusion : Cervicocephalic joint position sense can be affected by sitting postures, especially on the sagittal plane.

• Journal of KIISE
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• v.42 no.1
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• pp.15-22
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• 2015

In this paper, we present a case study for a drug repositioning simulation based on distributed supercomputing technology that requires highly efficient processing of large-scale computations. Drug repositioning is the application of known drugs and compounds to new indications (i.e., new diseases), and this process requires efficient processing of a large number of docking tasks with relatively short per-task execution times. This mechanism shows the main characteristics of a Many-Task Computing (MTC) application, and as a representative case of MTC applications, we have applied a drug repositioning simulation in our HTCaaS system which can leverage distributed supercomputing infrastructure, and show that efficient task dispatching, dynamic resource allocation and load balancing, reliability, and seamless integration of multiple computing resources are crucial to support these challenging scientific applications.

• IE interfaces
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• v.14 no.3
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• pp.255-262
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• 2001

Containerization of cargo transportation has been norm in the word wide maritime services, but containerized trades are typically unbalanced in terms of the number of inbound and outbound containers. Therefore it is critical for shipping companies to find operating policy such as the repositioning of empty containers or replenishing of short-term leasing containers from leasing companies to satisfy the freighter's demands of containers. This paper develops a simulation model using ARENA to establish shipping company's operational policy to relocate and replenish empty containers. Furthermore, this study proposes simple and heuristic empty container repositioning rules to minimize the relevant cost in terms of leasing, repositioning, and inventory holding costs.

• IE interfaces
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• v.24 no.2
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• pp.164-172
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• 2011

H maritime company in Korea had a long history of difficulty in obtaining enough empty containers to transport its commodities. Despite efforts to resolve the problem, the repositioning of empty containers between depots was still planned manually, which consumed much worker time. To automate the generation of reposition plans, we developed a planning system to optimize the company's reposition of empty containers between global depots with a linear programming model functioning as a key decision engine in the system. The model determines the route, volume and mode of transportation for repositioning empty containers from depots with surplus containers to those requiring containers, as well as the empty space of ships generated from the unloading or loading of full and empty containers. The system has been in operation in the company's global network since March 2008.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.3
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• pp.734-739
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• 2009

Benign paroxysmal positional vertigo(BPPV) is the most common peripheral vestibular disorder clinically. It causes dizziness or vertigo, lightheadedness, imbalance, and nausea. by a change of position of the head with respect to gravity. BPPV is very well explained by mechanical consequences of loose debris within the inner ear and oriental medical theory of vertigo resulting from Phlegm(痰). Therefore, for treatment of BPPV, we can consider not only oriental medical therapy but also Canalith Repositioning Procedure. We report four improved cases of dizziness patient diagnosed BPPV and Dam Hun(痰暈) treated by canalith repositioning procedure and herbal medication and acupuncture.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.3
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• pp.231-233
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• 2002

Temporary reconstruction of the mandibular continuity defect resulting from the ablative tumor surgery with a reconstruction plate can be used for the preservation of normal facial contour and oral function and for periodic follow up of recurrence. Reconstruction plates are adapted to the bone before the resection and provisionally fixated with some screws. Accurate contouring and adaptation are very important for the prevention of displacement of bony stumps and decubituous skin ulcer. However, if there is large expanding buccal tumor mass in mandible, it is very difficult or even impossible to contour the plate before resection. I, therefore, introduce the reconstruction plate application technique using a simple condylar repositioning miniplate after segmental mandibular resection.

• Journal of Oral Medicine and Pain
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• v.23 no.3
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• pp.277-280
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• 1998

The treatment of anterior disc displacement without reduction patients needs speicific treatment methods different from other Craniomandibular Disorders. Those are manual manipulation, anterior repositioning splint; ARS and step-back. It is well known that the use of Anterior Repositioning Splint is effective on relief of TMJ symptom. But the side effect of long- term ARS wearing, which is irreversible posterior open bite induction, has made many clinicians avoid ARS treatment. This report introduces a clinical case recently proven part- time wearing ARS method for treatment of Disc Displacement without reduction patient' that can reduce side effects with good efficacy. But now clinical statistical studies and basical histophysiological studies are more needed.