• Journal of Communications and Networks
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• 제11권1호
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• pp.57-71
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• 2009

Networking together hundreds or thousands of cheap sensor nodes allows users to accurately monitor a remote environment by intelligently combining the data from the individual nodes. As sensor nodes are typically battery operated, it is important to efficiently use the limited energy of the nodes to extend the lifetime of the wireless sensor network (WSN). One of the fundamental issues in WSNs is the coverage problem. In this paper, the border coverage problem in WSNs is rigorously analyzed. Most existing results related to the coverage problem in wireless sensor networks focused on planar networks; however, three dimensional (3D) modeling of the sensor network would reflect more accurately real-life situations. Unlike previous works in this area, we provide distributed algorithms that allow the selection and activation of an optimal border cover for both 2D and 3D regions of interest. We also provide self-healing algorithms as an optimization to our border coverage algorithms which allow the sensor network to adaptively reconfigure and repair itself in order to improve its own performance. Border coverage is crucial for optimizing sensor placement for intrusion detection and a number of other practical applications.

• Journal of Ubiquitous Convergence Technology
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• 제2권2호
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• pp.97-104
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• 2008

In this paper, we demonstrate the boundary effect of a deployed regions on the effective coverage of a mobile node. A node coverage area is not uniform throughout the entire deployed region. Assuming a uniform coverage can result in significant error in calculations. In this study, we analyze the behavior of a node's coverage area as a function of its transmission range throughout the entire deployed region. Using this analysis, a mathematical model for effective coverage in mobile wireless communications is created. The mathematical model considers the effect of the deployed regions boundaries on the coverage area of a mobile node. Lastly, we present simulation results to verify the analytical model and to compare this model with that of a uniform coverage.

• International Journal of Computer Science & Network Security
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• 제21권2호
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• pp.103-109
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• 2021

The study aimed to analyze the current situation of the electronic portal of the Northern Border University, in terms of content and components, the extent of quality of use, service assurance and integrity, linguistic coverage of objective content, in addition to assessing the efficiency of the Blackboard e-learning platform and measuring the degree of safety of the portal, in addition to measuring the extent of satisfaction, through a sample that included 135 faculty members, as the researcher was keen to apply the case study methodology with the use of the questionnaire as the main tool for measurement, and the study found that there is an average trend among faculty members in the degree of content for the components of the portal and electronic security While it rose to good use, and very good at using the Blackboard platform.

• 대한치과보철학회지
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• 제32권4호
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• pp.515-525
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• 1994

Impression taking is a very important procedure in complete denture fabrication for reproduction of the tissue surface from which obtain retention and support of denture base. Therefore, we can not construct retentive denture without precise impression taking. Retention in complete denture can be obtained by the closest contact between denture base and underlying tissue, maximum coverage and proper displacement of the border tissue for peripheral sealing. Therefore, it is very important to take impression of the border tissue displaced properly. Nowadays, impression of the border tissue is mainly taken by the border molding techniques by means of manual muscle trimming, but due to various muscle trimming methods as clinicians, it is difficult to select proper method. This technique is also bodersome to do and time-consuming procedure. Retention is also likely reduced, because of the recording excessive muscle movement than actural physiological border tissue movement. Therefore, the impression technique that records actual physiologic functional muscle movement is helpful to increase denture retention and easy to do. We named this technique a functional border molding technique. This technique is originally introduced by D. J. Neill and R. I. Nairn in 1968. We tried to fabricate complete denture by the impression by means of functional border molding technique for better retention and the convenience, and obtained good results.

• 한국산학기술학회논문지
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• 제9권5호
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• pp.1279-1283
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• 2008

위성DMB 서비스 시스템에서는 음영 지역을 커버하기 위한 중계기인 갭필러를 운용하고 있다. 하지만, 갭필러의 커버리지 영역에 한계가 있기 때문에 위성DMB 단말기가 갭필러의 커버리지 영역에서 벗어나면 위성으로부터 직접 신호를 수신한다. 여기서, 갭필러신호 서비스 커버리지와 위성신호 서비스 커버리지 사이에 경계지역이 발생하게 되며, 이러한 경계지역에서는 위성으로부터의 신호와 갭필러로부터의 신호간에 단말기의 복조창보다 차이가 큰 지연시간이 발생하므로 서비스 품질 저하가 발생하게 되는 문제점이 있다. 본 논문에서는 위성신호와 갭필러신호 사이에 발생되는 지연시간을 극복할 수 있도록 위성신호와 갭필러신호에 Delay를 추가하여 경계지역의 품질을 개선하는 방법을 제안한다. 갭필러시설이 전국적으로 확대되지 않은 서비스 초기단계에서 이 방법은 품질개선활동에 많은 도움이 되리라 사료된다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권3호
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• pp.901-920
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• 2015

Wireless Sensor Networks (WSNs) are widely used in geographically isolated applications like military border area monitoring, battle field surveillance, forest fire detection systems, etc. Uninterrupted power supply is not possible in isolated locations and hence sensor nodes live on their own battery power. Localization of sensor nodes in isolated locations is important to identify the location of event for further actions. Existing localization algorithms consume more energy at sensor nodes for computation and communication thereby reduce the lifetime of entire WSNs. Existing approaches also suffer with less localization coverage and localization accuracy. The objective of the proposed work is to increase the lifetime of WSNs while increasing the localization coverage and localization accuracy. A novel intelligent unmanned aerial vehicle anchor node (IUAN) is proposed to reduce the communication cost at sensor nodes during localization. Further, the localization computation cost is reduced at each sensor node by the proposed intelligent arc selection (IAS) algorithm. IUANs construct the location-distance messages (LDMs) for sensor nodes deployed in isolated locations and reach the Control Station (CS). Further, the CS aggregates the LDMs from different IUANs and computes the position of sensor nodes using IAS algorithm. The life time of WSN is analyzed in this paper to prove the efficiency of the proposed localization approach. The proposed localization approach considerably extends the lifetime of WSNs, localization coverage and localization accuracy in isolated environments.

• Archives of Plastic Surgery
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• 제33권2호
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• pp.155-160
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• 2006

Although several reports have been introduced about dual plane augmentation mammaplasty, the description of periareolar approach dual plane augmentation mammaplasty was few. This article describes specific characteristics, and different classification and techniques for the periareolar dual plane breast augmentation while postoperative scars resulted from inframammary crease approach caused complaints. A total of 124 patients(248 breasts) had periareolar dual plane augmentation surgery from 1998 to 2004. Anatomic implants were used in 43 cases. Most of the patients were satisfied with the outcomes of periareolar dual plane augmentation. Periareolar dual plane augmentation mammaplasty adjusts implant and tissue relationships to ensure adequate soft-tissue coverage while optimizing implant-breast parenchymal dynamics to offer increased benefits and fewer faults compared to a single pocket location in a wide range of breast types with minimal scars. Two types of dual plane classifications are discussed in this study for the periareolar approach exclusively. The boundaries of retroglandular dissection remain constant, as the costal origin of pectoralis major are divided. Type A dual plane implies that the inferior edge of pectoralis muscle lies below the inferior areolar border, and type B dual plane implies that the inferior edge lies above the superior areolar border.

• 한국의학물리학회지:의학물리
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• 제24권4호
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• pp.230-236
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• 2013

Our purpose is to present a novel technique for delivering craniospinal irradiation in the supine position using a perfect match, field-in-field (FIF) intrafractional feathering, and simple forward-optimization technique. To achieve this purpose, computed tomography simulation was performed with patients in the supine position. Half-beam, blocked, opposed, lateral, cranial fields with a collimator rotation were matched to the divergence of the superior border of an upper-spinal field. Fixed field parameters were used, and the isocenter of the upper-spinal field was placed at the same source-to-axis distance (SAD), 20 cm inferior to the cranial isocenter. For a lower-spinal field, the isocenter was placed 40 cm inferior to the cranial isocenter at a constant SAD. Both gantry and couch rotations for the lower-spinal field were used to achieve perfect divergence match with the inferior border of the upper-spinal field. A FIF technique was used to feather the craniospinal and spinal-spinal junction daily by varying the match line over 2 cm. The dose throughout the target volume was modulated using the FIF simple forward optimization technique to obtain homogenous coverage. Daily, image-guided therapy was used to assure and verify the setup. This supine-position, perfect match craniospinal irradiation technique with FIF intrafractional feathering and dose modulation provides a simple and safe way to deliver treatment while minimizing dose inhomogeneity.

• 대한치과보철학회지
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• 제37권6호
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• pp.819-824
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• 1999

The purpose of this article is to present a clinical case report for palateless complete denture. Despite the contravacy of palatal uncoverage in upper complete denture, palateless complete denture has some merits for upper edentulous patient. Following the uncovering of the palatal portion, the patient became easy to talk and restored the lost good tastes. He is happy despite of the decrease of the retention of the upper complete denture. Palateless complete denture is a compatible alternative fir upper edentulous patients in cases of gagging, large palatal torus and restoring the lost good tastes. The clinical points are as follows : 1. The remaning alveolar ridge should be ovoid and have enough width and height for the sup-port and retention. 2. The patient must have strong wish to the palateless complete denture. 3. Palatal beading made on the palatal peripheral border give good border sealing of the palatal flange and minimaized the prominence of the denture flange 4. The peripheral border of the palatal flange should be reduced as thin as possible for more comfort. 5. Upper artificial posterior teeth should be arranged over the alveolar ridge crest and inner incline of the buccal cusp relieved for denture stability while chewing. 6. For stability of palateless complete denture, bilateral balanced occlusion should be sttained. Palateless complete denture will restore the lost good tastes and more comfortable and physiologic to upper edentulous patients and a good alternative to full palatal coverage complete denture in the properly selected cases.

• Journal of Chest Surgery
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• 제27권10호
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• pp.888-892
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• 1994

Acquired, traumatic tracheoesophageal fistula [TEF] is rare and difficult problem to manage. This 55 years old man met with a roller accident of a tractor. During accident, he received a penetrating injury on the left upper sternal border. At local clinic, he received closed thoracotomy drainage [CTD]for relief of pneumothorax[left]. Three days after CTD, he complained abdominal pain and hematemesis. The endoscopy revealed large ulcer at the stomach, so he received subtotal gastrectomy. On 10th day post subtotal gastrectomy, he developed aspiration and coughing from a TEF. The esophagogram showed large TEF at the mid-trachea level. So he transfered to our hospital for operation. This patient was operated on for late TEF three weeks after injury. We have used absorble 4-0 Vicryl sutures to repair trachea. We repair all esophageal injuries with two layers of nonabsorbable silk suture. Where suture line on the esophagus, the strap muscle was interposed for reinforcement. And for feeding, the feeding jejunostomy was performed. Postoperatively the osteomyelitis of the manubrium site was developed, so on the 30th postoperative day, an ostectomy of manubrium, both clavicle and fight 1st, 2nd ribs, and the pectoralis major musculo-cutaneous flap coverage were performed.