• Journal of Korean Neurosurgical Society
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• 제30권6호
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• pp.769-773
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• 2001

Moyamoya disease is defined as the development of collateral pathways, associated with bilateral chronic progressive stenosis of the carotid fork. Persistent trigeminal artery is the vessel most frequently observed to persist into adult life among persistent carotid-basilar and carotid-vertebral anastomotic vessels. The authors present a man who had a sudden, severe headache and brain CT showed subarachnoid hemorrhage in left interpeduncular and prepontine cistern. Four-vessel angiogram revealed moyamoya disease associated with aneurysm arising from the junction of persistent trigeminal artery aneurysm and basilar artery. As a treatment, coil embolization was tried but it was failed because of anatomical difficulty of aneurysm. The aneurysm was successfully treated with clipping surgery 10 days later. To our knowledge, this is the first case being reported.

• 한국CDE학회논문집
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• 제11권1호
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• pp.27-40
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• 2006

The exchange of parameterized feature-based CAD models is important for product data sharing among different organizations and automation systems. The role of feature-based modeling is to gonerate the shape of product and capture design intends In a CAD system. A feature is generated by referring to topological entities in a solid. Identifying referenced topological entities of a feature is essential for exchanging feature-based CAD models through a neutral format. If the CAD data contains the modification history in addition to the construction history, a matching mechanism is also required to find the same entity in the new model (post-edit model) corresponding to the entity in the old model (preedit model). This problem is known as the persistent naming problem. There are additional problems arising from the exchange of parameterized feature-based CAD models. Authors have analyzed previous studies with regard to persistent naming and characteristics for the exchange of parameterized feature-based CAD models, and propose a solution to the persistent naming problem. This solution is comprised of two parts: (a) naming of topological entities based on the object spore information (OSI) and secondary name (SN); and (b) name matching under the proposed naming.

• The Korean Journal of Pain
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• 제18권2호
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• pp.222-225
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• 2005

Hiccups are due to an intermittent clonic spasm of the diaphragm. In most cases, hiccups are self-limiting disease, but persistent hiccups may be related to the presence of serious underlying systemic disease. Two patients who had persistent hiccups that were not controled by conventional methods and medications were referred to the pain clinic. We administered a single oral medication of gabapentin, and then the hiccups disappeared in both cases. We concluded that gabapentin should be considered as an alternative therapy to control persistent or intractable hiccup. It could be particularly useful for those patients with solid malignancies, either alone or as an "add-on therapy" with other oral agents.

• 한국통신학회논문지
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• 제32권9B호
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• pp.589-597
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• 2007

In this paper, a WDM metro ring consisting of access nodes with $FT-FR^n$ (Fixed Transmitter - n Fixed Receivers) is considered. A trade-off exists between node throughput and transmission fairness because the access nodes share wavelength channels. In order to eliminate the transmission unfairness and to increase throughput, the p-persistent medium access control (MAC) protocol is proposed: each node uses an empty optical slot to transmit a packet and make it available with the extraction of a transferred packet at the source access node, called source-stripping. The local empty slot can be used to transfer a head-of-line packet in the local buffer with probability p or it is used for the next downstream nodes with 1-p. The proposed MAC protocol provides better node throughput than the non-persistent protocol and exhibits better fairness index than the 1-persistent protocol in WDM ring networks. In addition, numerical analysis shows that the proposed MAC protocol maximizes the node throughput under uniform traffic conditions. For more detailed results, we use the network simulation under Poisson and self-similar traffic. Furthermore, unpredictable traffic constructed by the combination of the former and the latter is also considered. The reasonable probability of the p-persistent protocol for a given architecture can be determined through simulation.

• 사상체질의학회지
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• 제16권2호
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• pp.105-113
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• 2004

1. Objectives Hiccup is one of common symptoms clinically and caused by various etiologies. Persistent hiccup is defined as hiccup lasting more than 48 hours. We have tried researching effect of herbal medicines(Dokhwaljihwang-tang, Yangkyuksanhwa-tang). 2. Methods To heal the persistent hiccup, we used Dokhwaljihwang-tang and Yangkyuksanhwa-tang. 3. Results A Soyangin patient diagnosed to have persistent hiccup was, treated with Soyangin herbal medicines (Dokhwaljihwang-tang and Yangkyuksanhwa-tang), and change of his symptom & general condition was managed. 4. Conclusions The constitutional treatment with Soyangin herbal medicines(Dokhwaljihwang-tang, Yangkyuksanhwa-tang) may have an effect on management of persistent hiccup. Further study on management of this disease is needed.

• Computers and Concrete
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• 제17권6호
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• pp.723-737
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• 2016

In this paper an approach was described for determination of direction of sliding block in rock slopes containing planar non-persistent open joints. For this study, several gypsum blocks containing planar non-persistent open joints with dimensions of $15{\times}15{\times}15cm$ were build. The rock bridges occupy 45, 90 and $135cm^2$ of total shear surface ($225cm^2$), and their configuration in shear plane were different. From each model, two similar blocks were prepared and were subjected to shearing under normal stresses of 3.33 and $7.77kg/cm^{-2}$. Based on the change in the configuration of rock-bridges, a factor called the Effective Joint Coefficient (EJC) was formulated, that is the ratio of the effective joint surface that is in front of the rock-bridge and the total shear surface. In general, the failure pattern is influenced by the EJC while shear strength is closely related to the failure pattern. It is observed that the propagation of wing tensile cracks or shear cracks depends on the EJC and the coalescence of wing cracks or shear cracks dominates the eventual failure pattern and determines the peak shear load of the rock specimens. So the EJC is a key factor to determine the sliding direction in rock slopes containing planar non-persistent open joints.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제25권4호
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• pp.296-311
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• 2021

Topological Data Analysis (TDA), a relatively new field of data analysis, has proved very useful in a variety of applications. The main persistence tool from TDA is persistent homology in which data structure is examined at many scales. Representations of persistent homology include persistence barcodes and persistence diagrams, both of which are not straightforward to reconcile with traditional machine learning algorithms as they are sets of intervals or multisets. The problem of faithfully representing barcodes and persistent diagrams has been pursued along two main avenues: kernel methods and vectorizations. One vectorization is the Betti sequence, or Betti curve, derived from the persistence barcode. While the Betti sequence has been used in classification problems in various applications, to our knowledge, the stability of the sequence has never before been discussed. In this paper we show that the Betti sequence is unstable under the 1-Wasserstein metric with regards to small perturbations in the barcode from which it is calculated. In addition, we propose a novel stabilized version of the Betti sequence based on the Gaussian smoothing seen in the Stable Persistence Bag of Words for persistent homology. We then introduce the normalized cumulative Betti sequence and provide numerical examples that support the main statement of the paper.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 춘계학술대회
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• pp.203-205
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• 2022

Covid-19이 앞당긴 디지털 트랜스포메이션과 함께 원격근무 환경이 보편화되면서 정보 유출 공격에 의한 산업기밀과 개인정보 유출 피해 규모가 증가하고 있다. 최근 지능적이고 지속적인 정보 유출 공격은 대량의 정보를 빠르게 유출하는 것이 아니라 소량의 정보를 장기간에 걸쳐 지속해서 유출하기 때문에 탐지가 어려워 심각한 보안 위협이 되고 있다. 본 연구에서는 트래픽 특징을 기반으로 지능적이고 지속적인 정보 유출 공격을 탐지하는 프레임워크를 제안한다. 제안하는 방법은 페이로드가 암호화되어 있더라도, 트래픽 패턴, 패킷 사이즈, 메타데이터를 활용하여 지능적이고 지속적인 정보 유출 공격을 효과적으로 탐지할 수 있다.

• 한국초전도ㆍ저온공학회논문지
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• 제11권1호
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• pp.30-34
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• 2009

This paper deals with charging and persistent-current mode operating characteristics of BSCCO magnet load using high-temperature superconducting (HTS) power supply. The HTS power supply consists of two heater-triggered switches, an iron-core transformer with the primary copper winding and the secondary BSCCO solenoid, and a BSCCO magnet load. The magnet load was fabricated by double pancake winding and its inductance is about 21 mH. A hall sensor was installed at the middle of the magnet load to measure the current in the load. In order to investigate the efficient pumping characteristics, operating tests of heater-triggered switch with respect to dc heater current were carried out, and the electromagnet current was determined by considering saturation characteristics of its iron core. The saturation characteristics of charged current in the magnet load were observed with respect to various pumping periods: 12 s, 14 s, 24 s and 32 s. After charging the magnet load, the persistent current was measured. The operating characteristics of the persistent current mode were mainly determined by joint resistance and magnet load.

• Restorative Dentistry and Endodontics
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• 제47권3호
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• pp.26.1-26.10
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• 2022

Wegener's granulomatosis (WG) is a condition with immune-mediated pathogenesis that can present oral manifestations. This report describes the case of a patient diagnosed with WG 14 years previously, who was affected by persistent pain of non-odontogenic origin after successful endodontic treatment. A 39-year-old woman with WG was diagnosed with pulp necrosis and apical periodontitis of teeth #31, #32, and #41, after evaluation through a clinical examination and cone-beam computed tomography (CBCT). At the first appointment, these teeth were subjected to conventional endodontic treatment. At 6- and 12-month follow-up visits, the patient complained of persistent pain associated with the endodontically treated teeth (mainly in tooth #31), despite complete remission of the periapical lesions shown by radiographic and CBCT exams proving the effectiveness of the endodontic treatments, thus indicating a probable diagnostic of persistent pain of non-odontogenic nature. After the surgical procedure was performed to curette the lesion and section 3 mm of the apical third of tooth #31, the histopathological analysis suggested that the painful condition was likely associated with the patient's systemic condition. Based on clinical, radiographic, and histopathological findings, this unusual case report suggests that WG may be related to non-odontogenic persistent pain after successful endodontic treatments.