• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.132-132
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• 2011

For the programming volume of PRAM, Ge2Sb2Te5(GST) thin films have been dominantly used and prepared by physical vapor deposition (PVD), chemical vapor deposition (CVD), atomic layer deposition (ALD). Among these methods, ALD is particularly considered as the most promising technique for the integration of PRAM because the ALD offers a superior conformality to PVD and CVD methods and a digital thickness control precisely to the atomic level since the film is deposited one atomic layer at a time. Meanwhile, although the IST has been already known as an optical data storage material, recently, it is known that the IST benefits multistate switching behavior, meaning that the IST-PRAM can be used for mutli-level coding, which is quite different and unique performance compared with the GST-PRAM. Therefore, it is necessary to investigate a possibility of the IST materials for the application of PRAM. So far there are many attempts to deposit the IST with MOCVD and PVD. However, it has not been reported that the IST can be deposited with the ALD method since the ALD reaction mechanism of metal organic precursors and the deposition parameters related with the ALD window are rarely known. Therefore, the main aim of this work is to demonstrate the ALD process for IST films with various precursors and the conformal filling of a nano size programming volume structure with the ALD?IST film for the integration. InSbTe (IST) thin films were deposited by ALD method with different precursors and deposition parameters and demonstrated conformal filling of the nano size programmable volume of cell structure for the integration of phase change random access memory (PRAM). The deposition rate and incubation time are 1.98 A/cycle and 25 cycle, respectively. The complete filling of nano size volume will be useful to fabricate the bottom contact type PRAM.

• 대한기계학회논문집B
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• 제35권11호
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• pp.1177-1184
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• 2011

GTS 기술은 천연가스 하이드레이트 생산, 해양수송 및 재기화의 3 단계로 구성되며, 대규모 재기화 플랜트의 효율적 운용을 위해서는 하이드레이트 펠릿의 재기화에 필요한 열수 온도와 유량의 정확한 예측이 필수적이다. 하이드레이트 펠릿이 열수에서 해리할 때 펠릿 표면에서 분출되는 가스는 주변 유동장과 열전달 특성에 영향을 미칠 것이며 본 실험에서는 가압된 용기내의 중저온 열수에서 해리하는 메탄가스 하이드레이트 펠릿의 용해특성을 연구하였다. 해리과정 중 변화하는 펠릿 형상을 관찰하고 해리 완료시간을 측정함으로써 하이드레이트 전환율, 열수 온도 및 유동속도가 해리에 미치는 영향을 파악하였으며, 펠릿 표면에서 분출되어 상승하는 메탄가스 기포류가 유발한 2 차유동이 열전달률을 증가시켜 해리 완료시간이 단축됨을 확인하였다.

• 한국강구조학회 논문집
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• 제19권4호
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• pp.345-355
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• 2007

장대레일은 동절기에 기온하강으로 인한 인장력을 발생하는데 중위온도 이하로 떨어져 파단이 발생되면 인장파단과 레일 간에 틈이 발생되며 이를 개구부라 한다. 이 개구부를 차륜이 통과하면 충격하중이 발생하며, 큰 손실이 발생할 수 있는 열차탈선이 발생할 수 있다. 본 연구에서는 동적해석을 위해 개구부를 가진 궤도와 차량의 상호작용을 고려한 동적해석모델을 제안하였다. 궤도와 차량의 선형시스템은 비선형 헤르찌안 접촉 스프링에 의해 연성되었으며 전체 궤도-차량 시스템 운동방정식을 정식화하였다. 그리고 개구부에서의 상호작용 현상을 고려하여 궤도 불균일부의 함수를 정의하고 개구부에서의 전후방 레일 사이의 개구량을 고려하였다. 비선형 방정식을 풀기위해 동적해석은 수정된 Newton-Raphson 방법에 근거한 Newmark - $\beta$ 방법에 의해 수행되었다. 그리고 차량속도, 개구량, 레일지지강성에 따른 매개변수를 조건으로 수치해석을 수행하였다.

• 한국가금학회지
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• 제7권2호
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• pp.18-27
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• 1980

IBDV는 양계업이 전업화된 모든지역에서 발생하고 있다. 이 질병의 임상증상은 매우 특징적이기도 하지만 IBDV 감염시의 닭의 연령 또는 바이러스의 병원성에 따라 임상증상 업이 내과 하기도 한다. IBDV에 의한 BF의 종장이나 출혈성 병변은 감염 후 짧은 기간에만 관할되며 질병이 경과함에 따라 BF는 위축된다. IBDV는 감염력이 극히 높으며, 오염된 계분, 사료, 물 등에 의하여 전파된다. 이 바이러스는 외계 환경에 대하여 극히 높은 저항성을 갖고 있으며 Ribovirus군의 Diplorna 바이러스로서 크기는 55-60nm이다. IBDV는 계태아나 계태아 조직 또는 감수성이 있는 닭의 BF에서 용이하게 증식시킬 수 있다. agar gel을 사용한 면역 확산법은 IBDV 감염을 진단할 수 있는 가장 간편한 방법이다. IBDV에 대한 항체는 감염 후 1주일 후부터 증명되며 장기간 지속된다. 감수성 계군일 경우 높은 역가의 항체형성이나 지속은 계군의 연령에 비례한다. IBDV에 대한 모체이행 항체는 critical age때의 병아리를 야외 감염으로부터 보호하여 준다. IBDV 단독 감염에 의한 IBD 피해는 경미한 것이지만 면역부전증에 의하여 유발되는 복합성 질병인 Inclusion body hepatitis, 전염성 빈혈, 괴저성 피부염 등은 닭의 생산성을 크게 저하시킨다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.506-508
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• 2005

In general, organic TFTs are comprised of four components: gate electrode, gate dielectric, organic active semiconductor layer, and source and drain contacts. The TFT current, in turn, is typically determined by channel length and width, carrier field effect mobility, gate dielectric thickness and permittivity, contact resistance, and biasing conditions. More recently, a number of techniques and processes have been introduced to the fabrication of OTFT circuits and displays that aim specifically at reduced fabrication cost. These include microcontact printing for the patterning of metals and dielectrics, the use of photochemically patterned insulating and conducting films, and inkjet printing for the selective deposition of contacts and interconnect pattern. In the fabrication of organic TFTs, microcontact printing has been used to pattern gate electrodes, gate dielectrics, and source and drain contacts with sufficient yield to allow the fabrication of transistors. We were fabricated a pentacene OTFTs on flexible PEN film. Au/Cr was used for the gate electrode, parylene-c was deposited as the gate dielectric, and Au/Cr was chosen for the source and drain contacts; were all deposited by ion-beam sputtering and patterned by microcontact printing and lift-off process. Prior to the deposition of the organic active layer, the gate dielectric surface was treated with octadecyltrichlorosilane(OTS) from the vapor phase. To complete the device, pentacene was deposited by thermal evaporation and patterned using a parylene-c layer. The device was shown that the carrier field effect mobility, the threshold voltage, the subthreshold slope, and the on/off current ratio were improved.

• Geomechanics and Engineering
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• 제2권1호
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• pp.1-18
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• 2010

The analysis of structure response and design of buried structures subjected to dynamic destructive loads have been receiving increasing interest due to recent severe damage caused by strong earthquakes and terrorist attacks. For a comprehensive design of buried structures subjected to blast loads to be conducted, the whole system behaviour including simulation of the explosion, propagation of shock waves through the soil medium, the interaction of the soil with the buried structure and the structure response needs to be simulated in a single model. Such a model will enable more realistic simulation of the fundamental physical behaviour. This paper presents a complete model simulating the whole system using the finite element package ABAQUS/Explicit. The Arbitrary Lagrange Euler Coupling formulation is used to model the explosive charge and the soil region near the explosion to eliminate the distortion of the mesh under high deformation, while the conventional finite element method is used to model the rest of the system. The elasto-plastic Drucker-Prager Cap model is used to model the soil behaviour. The explosion process is simulated using the Jones-Wilkens-Lee equation of state. The Concrete Damage Plasticity model is used to simulate the behaviour of concrete with the reinforcement considered as an elasto-plastic material. The contact interface between soil and structure is simulated using the general Mohr-Coulomb friction concept, which allows for sliding, separation and rebound between the buried structure surface and the surrounding soil. The behaviour of the whole system is evaluated using a numerical example which shows that the proposed model is capable of producing a realistic simulation of the physical system behaviour in a smooth numerical process.

• 대한두개안면성형외과학회지
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• 제22권1호
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• pp.33-37
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• 2021

Background: Children with cleft lip and/or palate can be undernourished due to feeding difficulties after birth. A vicious cycle ensues where malnutrition and low body weight precludes the child from having the corrective surgery, in the absence of which the child fails to gain weight. This study aimed to identify the proportion of malnutrition, including the deficiency of major micronutrients, namely iron, folate and vitamin B12, in children with cleft lip and/or palate and thus help in finding out what nutritional interventions can improve the scenario for these children. Methods: All children less than 5 years with cleft lip and/or cleft palate attending our institute were included. On their first visit, following were recorded: demographic data, assessment of malnutrition, investigations: complete blood count and peripheral blood film examination; serum albumin, ferritin, iron, folate, and vitamin B12 levels. Results: Eighty-one children with cleft lip and/or palate were included. Mean age was 25.37±21.49 months (range, 3-60 months). In 53% of children suffered from moderate to severe wasting, according to World Health Organization (WHO) classification. Iron deficiency state was found in 91.6% of children. In 35.80% of children had vitamin B12 deficiency and 23.45% had folate deficiency. No correlation was found between iron deficiency and the type of deformity. Conclusion: Iron deficiency state is almost universally present in children with cleft lip and palate. Thus, iron and folic acid supplementation should be given at first contact to improve iron reserve and hematological parameters for optimum and safe surgery.

• International Journal of Computer Science & Network Security
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• 제22권2호
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• pp.341-347
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• 2022

This research is designed to help and offer hold up to complete the requirements of aged and disable in a home. The control approach and the tone approach are used to manage the house appliances. The major organize system implementation in technology of wireless to offer distant contact from a phone Internet Protocol connectivity for access and calculating strategy and appliance remotely. The planned system no need a committed server PC with value of parallel systems and offers a new communication-protocol to observe and control a house environment with more than just the switch functionality. To express the possibility and efficiency of this system, devices like as lights switches, power plugs, and motion-sensors have been included with the planned home control system and supply more security manage on the control with low electrical energy activate method. The rank of switches is corresponding in all this control system whereby all user interfaces indicate the real time existing status. This system planned to manage electrical-appliances and devices in house with reasonably low cost of design, user friendly interface, easily install and provide high security. Research community generally specified that the network "Reconnaissance Attacks" in IPv6 are usually impossible due to they will take huge challenge to carry out address scanning of 264 hosts in an IPv6 subnet."It being deployed of IPv6 shows that it definitely enhances security and undermines the probability". This research of the IPv6 addressing-strategies at present utilizes and planned a new strategy and move toward to "mitigate reconnaissance attacks".

• Journal of Electrochemical Science and Technology
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• 제12권4호
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• pp.458-464
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• 2021

Lithium ion batteries (LIBs) is a kind of rechargeable secondary battery, developed from lithium battery, lithium ions move between the positive and negative electrodes to realize the charging and discharging of external circuits. Zeolitic imidazolate frameworks (ZIFs) are porous crystalline materials in which organic imidazole esters are cross-linked to transition metals to form a framework structure. In this article, ZIF-67 is used as a sacrificial template to prepare nano porous carbon (NPC) coated cobalt nanoparticles. The final product Co/NPC composites with complete structure, regular morphology and uniform size were obtained by this method. The conductive network of cobalt and nitrogen doped carbon can shorten the lithium ion transport path and present high conductivity. In addition, amorphous carbon has more pores that can be fully in contact with the electrolyte during charging and discharging. At the same time, it also reduces the volume expansion during the cycle and slows down the rate of capacity attenuation caused by structure collapse. Co/NPC composites first discharge specific capacity up to 3115 mA h/g, under the current density of 200 mA/g, circular 200 reversible capacity as high as 751.1 mA h/g, and the excellent rate and resistance performance. The experimental results show that the Co/NPC composite material improves the electrical conductivity and electrochemical properties of the electrode. The cobalt based ZIF-67 as the precursor has opened the way for the design of highly performance electrodes for energy storage and electrochemical catalysis.

• 한국환경과학회지
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• 제31권4호
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• pp.365-368
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• 2022

The purpose of this study was to investigate the effects of desensitization and flooding on the behavior of dogs during grooming, focusing on their response to the sound and skin stimulation while using a clipper. A total of 20 adult dogs over two years of age with complete personality formation were included in the study. Ten dogs, of which three were Bichons (average weight 5 kg), four were Poodles (average weight 5 kg), and three were Malteses (average weight 4 kg), were subjected to the desensitization process. The remaining 10 adult dogs were subjected to the flooding experiment, and were of the same breed and average weight as the adult dogs used in the desensitization process. The desensitization and the flooding were performed three times a day (approximately 1 min per session) for 10 days. For desensitization, statistical significance was observed only on the fifth day, when compared by breed (p<0.05). Overall, when compared by measurement day, the results of desensitization for Bichon, Poodle and Maltese dogs were statistically significant (p<0.05). The results for the Bichon, Poodle, and Maltese dogs that were subjected to flooding were found to be statistically significant (p<0.05). There was a significant difference in the results of the flooding on the second and ninth days (p<0.05); however, flooding had no effect on the other days (p>0.05). Desensitization using the clipper, a beauty tool, was faster than flooding in achieving stabilization. In conclusion, desensitization and flooding showed positive results on the stress relief and emotions of dogs during grooming, with respect to cosmetic fear response.