• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.102-103
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• 2006

An important challenge in polymer-based advanced materials aimed at the fabrication of individualized functional molecular objects exhibiting specific and well-defined properties. The strategy developed in our group involves the construction of single giant highly branched macromolecules with controlled architecture and topology. Our presentation will be focused on the design of a series of comb copolymers with (a) PS-PI diblock branches, (b) randomly distributed PS and PI branches and janus type PS-comb-b-PI-comb diblocks. Their synthesis and a study of their behavior in solution and in bulk will be described.

• Journal of Korean Neurosurgical Society
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• v.47 no.3
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• pp.210-212
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• 2010

Sildenafil citrate ($Viagra^{(R)}$ Pfeizer US Pharmaceutical Group, New York, NY, USA) is a potent vasodilating agent to treat male erectile dysfunction. Among its adverse effects, hemorrhagic stroke has not been widely reported yet. We present a case of a 33-year-old healthy man who ingested 50 mg sildenafil a half hour before onset of headache, nervousness and speech disturbance. Head computed tomogram of this stuporous man showed huge intracerebral hemorrhage and thick subarachnoid hemorrhage, but angiography failed to disclose any vascular anomalies. Subsequent surgical procedure was followed, and rehabilitation was provided thereafter. Sildenafil seems to act by redistributing arterial blood flow, and concurrent sympathetic hyperactivity, which lead to such hemorrhagic presentation. Extreme caution should be paid on even in a young adult male patient wven without known risk factors.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2030-2035
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• 2005

In this paper, we study the distributed coordination of a set of synchronous, anonymous, memoryless mobile robots that can freely move on a two-dimensional plane but are unable to communicate directly. Based on this model, we analyze the application problem that consists in having a group of robots form a barricade line to protect from car traffic a crowd of demonstrators parading on the street. For the sake of robustness, we privilege fully decentralized solutions to the problem. In particular, we give a self-stabilizing distributed algorithm to address the problem, in this presentation

• Korean Journal of Bronchoesophagology
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• v.4 no.2
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• pp.205-210
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• 1998

Benign salivary gland tumors have relatively lower incidence, but it have various histopathologic diagnosis and biological behavior. Authors analyzed retrospectively 77 patients with benign salivary gland tumor who were treated surgically and had the following results. The most frequent age group was 5th decade, and sex distribution was not specific. The most common location was parotid gland(75.3%) and submandibular gland(20.8%) was next. Histopathologically, the most common salivary gland tumor was pleomorphic adenoma(82.7%) and Warthin's tumor(8.6%) was next. An asymptomatic mass was the most common presentation. Duration of symptoms and signs were mostly under the 5years(90.9%). Diameter of tumors was mostly under 4cm(76.7%). Parotid gland tumors were treated mostly with superficial parotidectomy and submandibular gland tumors were treated mostly with submandibular gland resection. The most common complication was facial nerve palsy(9 cases).

• International Journal of Internet, Broadcasting and Communication
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• v.6 no.1
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• pp.16-22
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• 2014

Clustering methods such as k-means and EM are the group of classification and pattern recognition, which are used in management science and literature search widely. In this paper, k-means and EM algorithm are compared the performance using by Weka. The winning Lottery numbers of 567 cases are experimented for our study and presentation. Processing speed of the k-means algorithm is superior to the EM algorithm, which is about 0.08 seconds faster than the other. As the result it is summerized that EM algorithm is better than K-means algorithm with comparison of accuracy, precision and recall. While K-means is known to be sensitive to the distribution of data, EM algorithm is probability sensitive for clustering.

• Imaging Science in Dentistry
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• v.43 no.1
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• pp.59-62
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• 2013

Non-Hodgkin's lymphoma (NHL) constitutes a group of malignancies those arises from cellular components of lymphoid or extranodal tissues. The head and neck is the most common area for the presentation of these lymphoproliferative disorders. Primary involvement of salivary glands is uncommon. This report described a case of a 73-year-old female patient who presented with involvement of both nodal and extranodal sites, with predominant involvement of salivary glands. The tumor staging worked up along with imaging, histopathological, and immunohistochemical findings were discussed. Computed tomographic images showed the involvement of Waldeyer's ring, larynx, orbit, and spleen. This report described imaging and prognostic tumor markers in diagnosing, treatment planning, and prognosis.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2002.12a
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• pp.383-386
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• 2002

In this paper, we investigated the pattern recognition performance of the numeric patterns (from 0 to 9) using DNA coding method. The pattern recognition performance of the DNA coding method is compared to the that of the GA(Genetic Algorithm). GA searches effectively an optimal solution via the artificial evolution of individual group of binary string using binary coding, while DNA coding method uses four-type bases denoted by A(Adenine), C(Cytosine), G(Guanine) and T(Thymine), The pattern recognition performance of GA and DNA coding method is evaluated by using the same genetic operators(crossover and mutation) and the crossover probability and mutation probability are set the same value to the both methods. The DNA coding method has better characteristics over genetic algorithms (GA). The reasons for this outstanding performance is multiple possible solution presentation in one string and variable solution string length.

• Journal of Korean Neurosurgical Society
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• v.65 no.3
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• pp.397-407
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• 2022

Abusive head trauma (AHT) is the most common and serious form of child abuse and a leading cause of traumatic death in infants and young children. The biomechanics of head injuries include violent shaking, blunt impact, or a combination of both. Neuroimaging plays an important role in recognizing and distinguishing abusive injuries from lesions from accidental trauma or other causes, because clinical presentation and medical history are often nonspecific and ambiguous in this age group. Understanding common imaging features of AHT can increase recognition with high specificity for AHT. In this review, we discuss the biomechanics of AHT, imaging features of AHT, and other conditions that mimic AHT.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.2
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• pp.46.2-46.2
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• 2019

The software group in Giant Magellan Telescope Organization (GMTO) is developing the GMT Software Development Kit (SDK) for the device control and the telescope operations. The SDK is dived into the modeling and the operation defining. In the modeling process, Domain Specific Language (DSL) can validate the availability of a model and generate a skeleton code automatically. After the modeling, the developer can simply define the device operation. All devices are connected via EtherCAT, and the SDK simplifies the network connection. This presentation will give an overview of the modeling process and development examples using the GMT SDK.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.8
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• pp.957-965
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• 1999

그룹간 공동 작업이나 화상 회의와 같은 그룹 통신의 수요가 늘어나면서 멀티캐스팅을 이용한 효율적인 데이타 전송에 대한 요구가 증가하고 있다. 특히 오디오나 비디오 데이타와는 달리 공동 문서 작업이나 그룹간 문서 전송을 위한 데이타 처리를 위해서는 어느 정도의 시간 손실이 있더라도 신뢰성을 보장할 수 있는 멀티캐스트 프로토콜이 요구된다. 그러나 멀티캐스트 전송에서의 신뢰성을 보장하기 위하여 손실 패킷에 대한 재전송 패킷이 전체 그룹으로 멀티캐스트 되는 것은 네트워크 상에 트래픽을 폭증시키는 요인이 된다. 이에 본 논문에서는 지역 그룹에서의 오류 회복을 위한 재전송 제한 기법을 제안하여 손실 패킷의 재전송 과정에서 발생하는 트래픽의 폭주를 제어하고자 한다. 이것은 재전송 패킷이 중복없이 다중 수신자에게 전송될 수 있도록 하여 그룹 내의 재전송 패킷의 양을 줄이고 필요없는 중복 패킷이 네트워크의 효율을 저하시키는 것을 방지하고자 하는 데 그 목적이 있다. Abstract As the size and the geographic span of communication groups increases, efficient data transmission schemes using Multicast service become more and more essential. Especially, unlike audio and video applications, for some collaborative applications and other data delivery components which require ordered and lossless delivery of data, Reliable Multicast Service is needed to ensure consistent presentation across multiple views. Thus error recovery by retransmission of loss data is provided in order to guarantee the reliability of multicast transmission protocol. However, redundant retransmission packets by multicast may cause traffic implosion on the Internet and it can be aggravated with continuous retransmission.This paper describes a Restricted Retransmission Mechanism as an error recovery method of multicast service in a local group, which can handle traffic implosion in retransmission process. It reduces redundant retransmission packets flowing into a local group and supports reliable multicast transmission. The goal of this mechanism is to reduce retransmission packets and decrease the load for group members and networks.