• Journal of information and communication convergence engineering
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• 제11권4호
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• pp.288-292
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• 2013

In this paper, a carbon implant is investigated in detail from the perspectives of performance advantages and side effects for the thick n-type metal-oxide-semiconductor field-effect transistor (n-MOSFET). Threshold voltage ($V_{th}$) adjustment using a carbon implant significantly improves the $V_{th}$ mismatch performance in a thick (3.3-V) n-MOS transistor. It has been reported that a bad mismatch occurs particularly in the case of 0.11-${\mu}m$ $V_{th}$ node technology. This paper investigates a carbon implant process as a promising candidate for the optimal $V_{th}$ roll-off curve. The carbon implant makes the $V_{th}$ roll-off curve perfectly flat, which is explained in detail. Further, the mechanism of hot carrier injection lifetime degradation by the carbon implant is investigated, and new process integration involving the addition of a nitrogen implant in the lightly doped drain process is offered as its solution. This paper presents the critical side effects, such as Isub increases and device performance shifts caused by the carbon implant and suggests an efficient method to avoid these issues.

• KIEAE Journal
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• 제12권6호
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• pp.29-38
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• 2012

The current building energy efficiency rating certification regulation on apartment houses evaluates only the saving rate of energy consumed during operation, i.e. use, of a building, but doesn't consider the energy consumptions and environmental load($CO_2$) emissions occurring during the whole lifetime of a building. So this study calculated the energy consumptions and environmental load emissions occurring during the whole lifetime of a building, selected reference schemes and alternative items by design variables to present a design draft considering energy efficiency and environmental performance, and evaluated the total cost by combining and calculating its direct cost(material and heating cost) and indirect cost(environmental cost), for an existing apartment house as an evaluation object. As a result of analysis, the change of heating cost by alternative items of design variables showed a 4~8% change rate compared to the reference scheme, and the material cost of design variable 7 showed a maximum 4.4 times change rate in the alternative plan 6 compared to the reference scheme. The environmental cost showed a similar change rate to the material cost change rate in general, but showed a similar environmental cost change rate to the heating cost change rate in case of design variables 4-1, 4-2, 7.

• Journal of Information Technology Applications and Management
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• 제24권2호
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• pp.71-80
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• 2017

Software reliability is one of the most elementary and important problems in software development In order to find the software failure occurrence, the instantaneous failure rate function in the Poisson process can have a constant, incremental or decreasing tendency independently of the failure time. In this study, we compared the reliability performance of the software reliability model using the parameters of Pareto life distribution with the intensity decreasing pattern and the shape parameter of Erlang life distribution with the intensity increasing and decreasing pattern in the software product testing. In order to identify the software failure environment, the parametric estimation was applied to the maximum likelihood estimation method. Therefore, in this paper, we compare and evaluate software reliability by applying software failure time data. The reliability of the Erlang and Pareto life models is shown to be higher than that of the Pareto lifetime distribution model when the shape parameter is higher and the Erlang model is more reliable when the shape parameter is higher. Through this study, the software design department will be able to help the software design by applying various life distribution and shape parameters, and providing basic knowledge using software failure analysis.

• 전산구조공학
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• 제3권1호
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• pp.109-116
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• 1990

본 연구에서는 사무실 적재하중을 체계적으로 조사.수집하여 등가등분하중을 산정하였다. 등가등분포하중은 슬래브, 보 기둥등의 부재별로 영향선을 이용하여 분석하였다. 여기에서 하중효과는 보와 슬래브에서는 휨모멘트, 기둥에서는 축력이 고려되었다. 산정된 등가등분포하중 자료로부터 적재하중의 확률적 특성과 영향면적과의 상관관계가 분석되었으며, 다른 하중조사결과와도 비교되었다. 분석된 적재하중의 확률모형을 이용하여 사용기간 동안의 극한값을 산정하였으며, 이 결과는 현행 설계적재하중과 비교되었다. 또한 보다 합리적인 설계적재하중을 결정할 수 있는 기초자료로서 영향면적에 따른 설게하중식을 제안하였다.

• ETRI Journal
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• 제44권3호
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• pp.389-399
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• 2022

Wireless sensor networks (WSNs) are one of the basic building blocks of Internet of Things (IoT) systems. However, the wireless sensing nodes in WSNs suffer from energy constraint issues because the replacement/recharging of the batteries of the nodes tends to be difficult. Furthermore, a number of realistic IoT scenarios, such as habitat and battlefield monitoring, contain mobile sensing elements, which makes the energy issues more critical. This research paper focuses on realistic WSN scenarios that involve mobile sensing elements with the aim of mitigating the attendant energy constraint issues using the concept of radio-frequency (RF) energy extraction. The proposed technique incorporates a cluster head election workflow for WSNs that includes mobile sensing elements capable of RF energy harvesting. The extensive simulation analysis demonstrated the higher efficacy of the proposed technique compared with the existing techniques in terms of residual energy, number of functional nodes, and network lifetime, with approximately 50% of the nodes found to be functional at the 4000th, 5000th, and 6000th rounds for the proposed technique with initial energies of 0.25, 0.5 and 1 J, respectively.

• Earthquakes and Structures
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• 제22권1호
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• pp.95-107
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• 2022

This paper introduces a novel, rigorous, and efficient probabilistic methodology for the performance-based optimal design (PBOD) of semi-active tuned mass damper (SATMD) for seismically excited nonlinear structures. The proposed methodology is consistent with the modern performance-based earthquake engineering framework and aims to design reliable control systems. To this end, an optimization problem has been defined which considers the parameters of control systems as design variables and minimization of the probability of exceeding a targeted structural performance level during the lifetime as an objective function with a constraint on the failure probability of stroke length damage state associated with mass damper mechanism. The effectiveness of the proposed methodology is illustrated through a numerical example of performance analysis of an eight-story nonlinear shear building frame with hysteretic bilinear behavior. The SATMD with variable stiffness and damping have been designed separately with different mass ratios. Their performance has been compared with that of uncontrolled structure and the structure controlled with passive TMD in terms of probabilistic demand curves, response hazard curves, fragility curves, and exceedance probability of performance levels during the lifetime. Numerical results show the effectiveness, simplicity, and reliability of the proposed PBOD method in designing SATMD with variable stiffness and damping for the nonlinear frames where they have reduced the exceedance probability of the structure up to 49% and 44%, respectively.

• 한국전기전자재료학회논문지
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• 제37권3호
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• pp.309-313
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• 2024

The key to determining the lifetime of OLED device is how much brightness can be maintained. It can be said that there are internal and external causes for the degradation of OLED devices. The most important cause of internal degradation is bonding and degradation in the excited state due to the electrochemical instability of organic materials. The structure of OLED modeled in this paper consists of a cathode layer, electron injection layer (EIL), electron transport layer (ETL), light emission layer, hole transport layer (HTL), hole injection layer (HIL), and anode layer on a glass substrate from top to bottom. It was confirmed that the temperature generated in OLED was distributed around the maximum of 343.15 K centered on the emission layer. It can be seen that the heat distribution generated in the presented OLED structure has an asymmetrically high temperature distribution toward the cathode, which is believed to be because the sizes of the cathode and positive electrode are asymmetric. Therefore, when designing OLED, it is believed that designing the structures of the cathode and anode electrodes as symmetrically as possible can ensure uniform heat distribution, maintain uniform luminance of OLED, and extend the lifetime. The thermal distribution of OLED was analyzed using the finite element method according to Comsol 5.2.

• 한국임상약학회지
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• 제26권1호
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• pp.59-69
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• 2016

Background: The subcutaneous formulation of biologic disease-modifying antirheumatic drugs (DMARDs) was preferred due to favored self-administration and would be an economical treatment option for patients with rheumatoid arthritis. This study was to compare the economic impact of biologic DMARDs administered by subcutaneous injection in patients with rheumatoid arthritis who had inadequate response to conventional DMARDs. Methods: The cost-minimization analysis was conducted to estimate the lifetime health care costs of treatment sequences with subcutaneous biologic DMARDs as first-line therapy from a health care system perspective. The Markov model was developed to represent the transitions through treatment sequences based on American College of Rheumatology response rate and discontinuation rate. The health care costs comprised the cost of medications, administration, dispensing, outpatient visits, test/diagnostic examination, palliative therapy and treatment of serious infection. All costs were expressed in 2016 Korean Won (KRW) and discounted at 5%. Results: The mean lifetime health care cost per patient was lowest in the etanercept sequence, which was estimated at KRW 63,441,679. The incremental costs of the treatment sequence started with adalimumab, golimumab, abatacept, and tocilizumab were KRW 7,985,730, KRW 4,064,669, KRW 2,869,947, and KRW 4,282,833, respectively, relative to etanercept sequence. These differences in costs mainly were attributable to medication costs. One-way and probabilistic sensitivity analyses confirmed that etanercept represented the option with the lowest cost compared with comparators. Conclusion: This study found that etanercept is likely a cost-saving treatment option among subcutaneous biologic DMARDs in patients with rheumatoid arthritis.

• 한국진공학회지
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• 제22권5호
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• pp.250-256
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• 2013

양전자 소멸 분광법으로 발광 박막 시료에 3.0 MeV 에너지를 가진 양성자 빔을 $0.0{\sim}20.0{\times}10^{13}$ protons/$cm^2$의 조사에 의해 생성된 결함을 측정하여 박막구조 특성에 대하여 실험하였다. 동시 계수 도플러 넓어짐 양전자 소멸법 스펙트럼의 수리적 해석 방법인 S-변수를 사용하고, 양전자 수명 측정 방법에 의한 양전자 수명 ${\tau}_1$과 ${\tau}_2$, 이에 따른 세기 $I_1$과 $I_2$를 사용하여, 박막구조에 대한 결함 특성 변화를 측정하였다. 측정된 S-변수는 박막에 조사된 양성자의 빔 조사량에 따라 양성자가 빈자리에 포획되어 감소하는 값을 보였다. 양전자 수명 ${\tau}_1$은 증가하고, ${\tau}_2$은 일정한 값을 나타내었으나, 반면에 세기 $I_1$과 $I_2$는 큰 변화가 없었다. 그 이유는 양성자 조사 빔의 변화에 따라서 단일 빈자리의 크기는 증가하고, 다 결정체 알갱이 빈자리 때문에 양성자에 의한 다수의 빈자리 결함의 양은 큰 차이가 없기 때문이다. 그리고 Bragg 피크로 인하여 박막 시료의 특정 깊이에 결함을 형성하여 박막 전체의 결함으로 잘 나타나지 않기 때문으로 판단된다.

• 생약학회지
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• 제33권1호통권128호
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• pp.57-63
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• 2002

The purpose of this research was to investigate the effects of dried orange peel compound intaking and exercise training on the physique, body fat, and concentration bloodlipid in obese women. Ninety-seven volunteers(mean age 21.47 ${\pm}$ 1.47 yrs), all over 30% of body fat, agreed to Participate and were placed in 4 groups: dried orange peel compound intaking and exercise group(n=25), only exercise group(n=25), only dried orange peel compound intaking group(n=24), and control group(n=20). The subjects who joined this project were asked to take dried orange peel compound(2 times/day, 30 ml/time) or participate in exercise program(3 times/week, 70 min/day), depending on particular group for 12 weeks. They were tested on their height, weight, circumference of chest, abdomen, hip, and thigh, body fat%, total-cholesterol(TC), HDL-C, LDL-c, and triglyceride(TG) at the beginning and the end of the 12-weeks program. For data analysis, paired t-tests and ANCOVAs were used. The intaking of dried orange peel compound was influenced on weight, circumference of chest, abdomen, hip, and thigh, body fat%, HDL-C, LDL-C, and TG. The exercise participation had almost same effects on those dependent variables. Furthermore, the dried orange peel compound intaking along with exercise training was the most effective on those dependent variables among them. Therefore, these results indicate that dried orange peel compound intaking, like exercise, may be useful for controling weight, body fat, HDL-C, LDL-C, and TG.