• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.3
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• pp.442-450
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• 2001

Experiments were carried out on agglomeration of bipolarly charged particles in an alternating current electric field. Laboratory-scale setup was built and experiments were conducted at atmospheric condition. DOS(Di-octyl Sebacate) particles with 100% purity were generated by an atomizer. The particles were branched into two, each of which passed through a wire-to-plate type charging section where a positive or a negative DC high voltage was applied and was charged positively or negatively. These bipolarly charged particles together passed through an agglomeration section where an $\pm$20kV AC power was applied between two plates. The resident time in the agglomeration section was adjusted as l sec. Particle sampling was made by a cascade impactor (MOUDI). The effect of agglomeration system on the reduction ratio of particles below l ㎛ was 42∼45%. Effect of AC frequency on the particle size distribution was found insignificant.

• Journal of Korean Clinical Nursing Research
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• v.17 no.3
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• pp.443-454
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• 2011

Purpose: The purpose of this study was to investigate the predictors of delirium in patients after orthopedic surgery. Methods: Participants were 121 orthopedic surgery patients from one university affiliated hospital located in Seoul. The instrument of Delirium Observation Screening Scale (DOS) developed by Schuurmans et al. (2003) was utilized. Data were collected from September 1st, 2010 to March 31st, 2011 and analyzed using SPSS 12.0 with descriptive statistics, t-test, chi-square test and logistic regression. Results: The delirium in patients after orthopedic surgery was occurred in 9 (7.4%) out of 121 patients. Several factors were associated with the delirium occurrence age, admission route, preadmission Activity of Daily Living (ADL), preadmission hearing aid use, preadmission walking degree, diagnosis, type of surgery, Intensive Care Unit (ICU) stay after surgery, restraint, drainage tube, time of admission to surgery, preoperative albumin and preoperative sodium. Preadmission ADL, preoperative sodium and time of admission to surgery were the significant predictors of the delirium occurrence. Conclusion: Study results may help nurses predicting and detecting delirium early and providing preventive measures to the patients with high risk of delirium after orthopedic surgery.

• Imaging Science in Dentistry
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• v.49 no.2
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• pp.171-176
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• 2019

The available methods for veneer evaluation are limited to clinical and radiographic examinations, which may not allow the appropriate identification of failure. In this report, we demonstrate the use of optical coherence tomography (OCT) as a noninvasive diagnostic and follow-up method to evaluate gingival recovery and the adhesive interface in aesthetic oral rehabilitation involving periodontal plastic surgery and ceramic laminate veneers. OCT was efficient for evaluating both soft and hard tissues, as well as the quality of the adhesive interface. In conclusion, OCT was found to be a promising approach for the professional evaluation of aesthetic oral rehabilitation, as it was capable of generating images that enabled the analysis of gingival recovery and the adhesive interface.

• Coupled systems mechanics
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• v.8 no.2
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• pp.129-146
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• 2019

The main goal of this work is to develop a numerical simulator to study an isothermal single-phase two-component flow in a naturally fractured oil reservoir, taking into account advection and diffusion effects. We use the Peng-Robinson equation of state with a volume translation to evaluate the properties of the components, and the discretization of the governing partial differential equations is carried out using the Finite Difference Method, along with implicit and first-order upwind schemes. This process leads to a coupled non-linear algebraic system for the unknowns pressure and molar fractions. After a linearization and the use of an operator splitting, the Conjugate Gradient and Bi-conjugated Gradient Stabilized methods are then used to solve two algebraic subsystems, one for the pressure and another for the molar fraction. We studied the effects of fractures in both the flow field and mass transport, as well as in computing time, and the results show that the fractures affect, as expected, the flow creating a thin preferential path for the mass transport.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.24 no.6
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• pp.528-534
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• 2021

Purpose: Living-donor liver transplant emerged as an alternative treatment for end stage liver disease due to the lack of cadaveric organs availability that met the demand. In Portugal, pediatric living-donor liver transplant (P-LDLT) was initiated in 2001 in Portugal in order to compensate for the scarcity of cadaveric organs for such cases. The aim of this study was to retrospectively analyze the morbi-mortality of the 28 donors included in P-LDLT program performed at Coimbra's Pediatric Hospital (CHUC), a Portuguese reference center. Methods: We retrospectively collected pertinent donor data and stratified complications according to Clavien's scoring system. Results: In total, 28.6% (n=8) of the donors had surgical complications. According to Clavien-Dindo's classification, two donors had major complications (Clavien grade ≥3), four donors had grade 2 complications, and two donors had grade 1 complications. There were no P-LDLT-related mortalities in the present case series. The most common verified complications were biliary tract injuries and superficial incisional infections, which are consistent with the complications reported in worldwide series. Conclusion: These patients from CHUC shows that donor hepatectomy in P-LDLT is a safe procedure, with low morbidity and without mortality.

• Journal of the Korea Society of Computer and Information
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• v.24 no.10
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• pp.41-48
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• 2019

In 2018, Cui et al proposed a three-factor remote user authentication scheme using biometrics. Cui et al claimed that their authentication scheme is vulnerable to eavesdropping attack, stolen smart card attack, and especially Dos(denial-of-service) attack. Also they claimed that it is safe to password guessing attack, impersonation attack, and anonymity attack. In this paper, however, we analyze Cui et al's authentication scheme and show that it is vulnerable to replay attack, insider attack, stolen smart card attack, and user impersonation attack, etc. In addition, we present the design flaws in Cui et al's authentication scheme as well.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.4
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• pp.3-11
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• 2003

It is very important to detect and remove original sources of various attacks through networks. One of the effective method to detect the sources is traceback systems. In this paper, we design and implement an agent-based traceback system that does not require the reaction of routers and administrators and does not need numerous log data. In the design, we introduce a traceback server and traceback agents in each network Using sniffing and spoofing, the server transmits a packet with a specific message. The agents detect the packet and provide the information for the server to trace back the original source.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.5
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• pp.115-124
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• 2005

We propose a new binding update(BU) protocol between mobile node(CN) and correspondent node(CN) for the purpose of preventing redirect attacks and DoS attacks observed from the existing BU protocols and enhancing the efficiency of the BU protocol. Home agent plays a role of both authentication server validating BU message and session key distribution center for MN and CN. Also propose the stateless Diffie-Hellman key agreement based on cryptographically generated address (CGA). Suity of our proposed Protocol is analyzed and compared with other protocols. The proposed protocol is more efficient than previous schemes in terms of the number of message flows and computation overhead and is secure against both redirect and DoS attacks.

• Nuclear Engineering and Technology
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• v.54 no.10
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• pp.3849-3854
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• 2022

The present work aims to optimize the radiation protection efficiency for ion-selective containers used in the liquid treatment for the nuclear power plant (NPP) cooling cycle. Some naturally occurring rocks were examined as filler materials to reduce absorbed dose and equivalent dos received from the radioactive waste container. Thus, the absorbed dose and equivalent dose were simulated at a distance of 1 m from the surface of the radioactive waste container using the Monte Carlo simulation. Both absorbed dose and equivalent dose rate are reduced by raising the filler thickness. The total absorbed dose is reduced from 7.66E-20 to 1.03E-20 Gy, and the equivalent dose is rate reduced from 183.81 to 24.63 µSv/h, raising the filler thickness between 0 and 17 cm, respectively. Also, the filler type significantly affects the equivalent dose rate, where the redorded equivalent dose rates are 24.63, 24.08, 27.63, 33.80, and 36.08 µSv/h for natural rocks basalt-1, basalt-2, basalt-sill, limestone, and rhyolite, respectively. The mentioned results show that the natural rocks, especially a thicker thickness (i.e., 17 cm thickness) of natural rocks basalt-1 and basalt-2, significantly reduce the gamma emissions from the radioactive wastes inside the modified container. Moreover, using an outer cementation concrete wall of 15 cm causes an additional decrease in the equivalent dose rate received from the container where the equivalent dose rate dropped to 6.63 µSv/h.

• Iberoamérica
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• v.11 no.1
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• pp.39-70
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• 2009

Este estudo tem por objetivo analisar, do ponto de vista da alquimia, O Alquimia, considerado uma das obras mais representativas do escritor brasileiro Paulo Coelho. Para tanto, começamos a observar as características da alquimia à qual o próprio autor disse que dedicava 11 anos para estudá-la por volta da década de 1970 quando o mundo estava sofrendo grandes mudanças sociais. Desta observação, entendemos que, sendo uma projeção do 'inconsciente' conforme diz C. G. Jung, a essência da alquimia consiste resumidamente nos seguintes conceitos: união de elementos opostos, transformação e salvação. A partir daí, tentamos estudar como esses coneitos estão diluídos na estrutura de O Alquimia e como a experiência do Paulo Coelho com a alquimia interioriza-se no mundo literário dele. E entendemos que os conceitos simbólicos da alquimia e as mensagens que a experiência do escritor com a alquimia configura em suas obras literárias compartilham a quase mesma dimensão semântica. Percebemos também que em alguns aspectos as idéias do escritor consolidadas em torno da sua pesquisa da alquimia vão às vezes além dos conceitos genéricos da alquimia, atingindo assim uma dimensão bastante peculiar e fundamental para compreender melhor o seu universo literário: para ele que se declara católico, Deus não é católico nem islâmico, nem budista, nem hinduista. Por exemplo, ele diz que Deus é um só e é que o Seu nome varia dependendo da religião, porque cada religião precisa escolher um nome para chamá-lo.