• 소음진동
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• 제10권6호
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• pp.1083-1093
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• 2000

이 논문은 지능구조물의 실시간 적응진동제어를 위해 유전자 알고리즘을 이용하여 Positive Position Feedback(PPF) 제어기를 조정하는 것과 관련이 있다. 유전자 알고리즘은 최적변수를 찾는데 있어 국소 최소점이 아닌 전체적인 최적점을 찾을 수 있는 능력이 있다. PPF 제어기는 다른 진동모드에 영향을 주지 않으면서 특정 진동모드의 감쇠를 증가시킬 수 있는 장점을 가지고 있는 반면에 효과적인 진동제어를 위해서는 제어하고 자하는 진동모드의 고유진동수를 정확히 알아야하는 단점이 있다. 본 연구에서는 유전자 알고리즘을 이용하여 실시간으로 PPF 제어기가 필요로 하는 변수값을 추적할 수 있는 알고리즘을 개발하여 그 타당성을 실험으로 증명하였다. 실험결과는 PPF 제어기의 실시간 조정이 성공적으로 이루어져 진동제어가 효과적으로 이루어졌음을 보여주고 있다.

• Journal of Astronomy and Space Sciences
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• 제18권1호
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• pp.1-6
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• 2001

In this paper we investigate the properties of advection-dominated accretion flows (ADAFs) in case that outflows carry away infalling matter with its angular momentum and energy. Positive Bernoulli number in ADAFs allow a fraction of the gas to be expelled in a form of outflows. The ADAFs are also unstable to convection. We present self-similar solutions for advection-dominated accretion flows in the presence of outflows from the accretion flows(ADIOS). The axisymmetric flow is treated in variables integrated over polar sections and the effects of outflows on the accretion flow are parameterized for possible configurations compatible with the one dimensional self-similar ADAF solution. We explicitly derive self-similar solutions of ADAFs in the presence of outflows and show that the strong outflows in the accretion flows result in a flatter density profile, which is similar to that of the convection-dominated accretion flows(CDAFs) in which convection transports the angular momentum inward and the energy outward. There two different versions of the ADAF model should show similar behaviors in X-ray spectrum to some extent. Even though the two models may show similar behaviors, they should be distinguishable due to different physical properties. We suggest that for a central object of which mass is known these two different accretion flow should have different X-ray flux value due to deficient matter in the wind model.

• Spatial Information Research
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• 제15권1호
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• pp.1-14
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• 2007

최근 'u-City'라는 명제 하에 도시민의 일상적인 삶의 토대로서의 물리적 도시환경과 첨단정보기술의 통합이 본격적으로 시도되고 있다. 이에 따라 u-City의 효용성과 파급효과에 대한 기대심리와 u-City 구현의 걸림돌이 되는 다양한 법제도 및 기술적 제약요인들로 인한 우려의 목소리가 공존하고 있다. 이에 본 연구는 u-City의 성공적인 구현을 위해 시급히 해결해야 할 현안과제를 도출하고 시사점을 제시함으로써, u-City 구현에 대한 회의적이고 부정적인 시각을 해소해나가고자 한다. 이러한 취지에서 이 연구에서는 u-City구현과 관련된 각계 각층의 전문가들의 의견을 수렴하여 u-City구현을 위한 u-인프라, u-서비스, 정책(법제도)측면의 현안과제와 u-City의 추진단계별 현안 과제를 도출하고 시사점을 제시하였다.

• 지식경영연구
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• 제14권5호
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• pp.55-79
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• 2013

This study primarily focused on the opportunity realization process of a korean venture firm based on university. This research examined the relationship between entrepreneurial intent and organizational learning produced in a sustainable opportunity realization process with technology/market domain shifts. Therefore, this research explores the determinants of sustainable growth of a venture firm at the organizational level and suggests optimal solutions for promoting entrepreneurial intent and opportunity realization for many entrepreneurs. The results showed that CEO's entrepreneurial intent is a key driving factor that can positive impacts on opportunity recognition and organizational learning based on university's expertise. Furthermore, the orientation of a entrepreneur can affect venture's technology/market domain shift through the advanced technological knowledge of university. In conclusion, this research sheds light on the growth of a venture firm based on university suggesting more customized solutions for many entrepreneurs. Implications for the results and the future directions are discussed.

• 대한간호학회지
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• 제37권5호
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• pp.724-735
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• 2007

Purpose: The purpose of this study was to explore and describe the experiences of the family caregivers using a nursing home for their elderly family members. Method: Participants for this study were 1 man and 9 women caregivers. Data was collected through in-depth interviews from October, 2005 to April, 2006 and analyzed using Strauss and Corbin's grounded theory methodology. Results: "Finding a way to live together" emerged as a core category and it reflected expanding consciousness allowing them to see each other in a more positive view. The basic social process of "finding a way to live together" includes 3 phases: 1) recognizing the problems, 2) finding solutions to the problems, and 3) accepting the changes in their surrounding. Lack of privacy, family troubles, extreme distress, and unavailable caregivers are reflected in the process of recognizing the problems. The process of finding solutions was making a decision, obtaining family agreement, choosing the best nursing home, and enduring the financial burden. Possible outcomes of the last phase include recovering peace of mind and continuing conflict. Conclusion: Findings from this study offer suggestions for developing a strategy to help not only the elderly but also the family caregivers.

• The Journal of Asian Finance, Economics and Business
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• 제8권5호
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• pp.335-343
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• 2021

Profit generation is one of the main goals of small- and medium-sized enterprises (SMEs). SMEs have deployed a number of solutions to increase profits, including solutions to improve their financial advantage. The question is how to help SMEs make better and more effective decisions to improve their competitive advantage in order to improve their financial performance. The aim of this research is to examine the impact of competitive advantage on financial performance in small- and medium-sized enterprises (SMEs) in Hanoi. A survey of 120 accountants, sales staff and boards of directors of SMEs was conducted to collect data. Through quantity methodology, we used Cronbach's Alpha, EFA and correlation analysis to determine the relationship between competitive advantage and dependent variable - financial performance. The results showed that the competitive advantage had a positive relationship with financial performance. There is not, statistically, significant difference in the level of financial performance in SMEs in Hanoi in terms of genders and between the mentioned three groups of job descriptions. From the findings, this study suggests several recommendations to improve financial performance such as increase sales and increase profits. The results are considered as a useful reference for establishing policies to attract customers toward sustainable development of firms.

• Journal of the Korean Wood Science and Technology
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• 제47권1호
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• pp.110-123
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• 2019

This work was conducted to examine the relationship between lignin content and the durability of larch (LAR) pellets. LAR sawdust was immersed in tap water (TW), sulfuric acid (AC) and sodium hydroxide (AK) solutions, and then the immersed sawdust was used for pellet fabrication. Klason lignin (KL) content of the immersed LAR, contents of soluble lignin (SL) and monomeric sugars liberated from the immersion of LAR, and durability of LAR pellets were measured. KL content decreased as the concentration of AC and AK solutions increased, but glucose content increased with increase in AC and AK concentration. Durability of wood pellets fabricated using non-immersed LAR sawdust was the highest, followed by those made using TW-, AK- and AC-immersed sawdust. LAR pellets became more durable as the concentration of KL and SL increased, but a significant positive correlation was found only between pellet durability and KL content. Through the fluorescent microscopic observation and SEM-EDX analysis, it was verified that lignin content of non-immersed LAR pellets was higher than that of AC- and AK-immersed LAR pellets. These results suggest that lignin might contribute to an increase in inter-particle bonding in wood pellets.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권1호
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• pp.20-34
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• 2021

Today, IoT devices are flooding, and traffic is increasing rapidly. The Internet of Things creates a variety of added value through connections between devices, while many devices are easily targeted by attackers due to security vulnerabilities. In the IoT environment, security diagnosis has problems such as having to provide different solutions for different types of devices in network situations where various types of devices are interlocked, personal leakage of security solutions themselves, and high cost, etc. To avoid such problems, a TCP-based active scan was presented. However, the TCP-based active scan has limitations that it is difficult to be applied to real-time systems due to long detection times. To complement this, this study uses UDP-based approaches. Specifically, a lightweight active scan algorithm that effectively identifies devices using UPnP protocols (SSDP, MDNS, and MBNS) that are most commonly used by manufacturers is proposed. The experimental results of this study have shown that devices can be distinguished by more than twice the true positive and recall at an average time of 1524 times faster than Nmap, which has a firm position in the field.

• 유통과학연구
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• 제19권9호
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• pp.53-64
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• 2021

Purpose: The current study aims and reviews the current state of research in green awareness' distribution structure using the ecological theory of Ted Hughes who was regarded as one of the best English poets of the 20 century. Ted poetry has innovated ecological distribution. It has inspired so many young people to have a positive energy impact on the environment. Research design, data and methodology: Action research design is an approach used extensively in qualitative content analysis. This design starts by adopting an exploratory claim that develops the research objectives, hence instigating the action process, which involves several strategies. This type of design involves a cyclic process of stance then action. Results: According to the investigation, there are nine solutions that can deal with the green distribution based on previous literature review, applying an ecological approach of Ted Hughes to green awareness distribution. The solutions figured out that Ted's novels had an innovative impact on the environment as it is clear that information is given to society. Conclusions: It is observed that having a highly professional environment is good enough for a structure to go green. But, on the other hand, polluting our environment can endanger species by causing health diseases and environmental problems.

• Asian-Australasian Journal of Animal Sciences
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• 제17권9호
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• pp.1277-1280
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• 2004

The effect of duodenal infusion with feed oligo-peptide solution on portal absorption of amino acids was investigated in poultry under unanaesthetized conditions. Four peptide solutions were used in the experiment: enzymatic hydrolysates from fish meal, soybean meal, cottonseed meal and rapeseed meal proteins with average molecular weights less than 3,000 Da and 1,000 Da, respectively. Intestinal absorptions of these oligo-peptide solutions were compared by determining the concentration of free amino acid (FAA) in portal blood after the duodenal administrations of oligo-peptide solutions. Absorptive intensity and balance were used to estimate the intestinal absorption rate of amino acids. The absorptive intensities of amino acids were highest for the fish and soybean meal oligo-peptides. The ratios of amino acids absorbed in the portal blood from fish and soybean meal oligo-peptides were more similar to the composition of the infused amino acids than that observed from the cottonseed and rapeseed meal oligo-peptides. A positive correlation was found between absorption rate and proportion of PAA in the oligo-peptides. The higher absorption rate could be contributed to the higher proportion of peptide bound amino acids (PAA). The results suggest that fish and soybean meal protein are significantly more easily hydrolyzed into oligo-peptides (p<0.05) in the gastrointestinal tracts of poultry and as such can be utilized more effectively by body tissues.