• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 추계학술대회논문집
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• pp.667-673
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• 2000

A number of issues related with the vibrational behavior of pretwisted rotating beams featuring anisotropic properties and incorporating adaptive capabilities are considered in this paper. The adaptive capabilities are provided by a system of piezoactuators bonded or embedded into the structure. Based on the converse piezoelectric effect and on the out of phase activation, boundary control moments are pizoelectrically induced at the beam tip. A feedback control law relating the induced bending moments with the kinematical response quantities appropriately selected is used, and its beneficial effects, considered in conjunction with that of the beam anisotropy and structural pretwist upon the eigenvibration characteristics are highlighted

• 대한수학회보
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• 제53권2호
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• pp.561-568
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• 2016

In this paper, the effect of absolute values on the behavior of functions f in the spaces $\mathcal{Q}_K$ is investigated. It is clear that $g{\in}\mathcal{Q}_K({\partial}{\mathbb{D}}){\Rightarrow}{\mid}g{\mid}{\in}\mathcal{Q}_K({\partial}{\mathbb{D}})$, but the converse is not always true. For f in the Hardy space $H^2$, we give a condition involving the modulus of the function only, such that the condition together with ${\mid}f{\mid}{\in}\mathcal{Q}_K({\partial}{\mathbb{D}})$ is equivalent to $f{\in}\mathcal{Q}_K$. As an application, a new criterion for inner-outer factorisation of $\mathcal{Q}_K$ spaces is given. These results are also new for $Q_p$ spaces.

• Structural Engineering and Mechanics
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• 제19권5호
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• pp.477-501
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• 2005

In this study, a new smart beam finite element is proposed for the finite element modeling of beam-type smart structures that are equipped with bonded plate-type piezoelectric sensors and actuators. Constitutive equations for the direct piezoelectric effect and converse piezoelectric effect of piezoelectric materials are considered in the formulation. By using a variational principle, the equations of motion for the smart beam finite element are derived. The proposed 2-node beam finite element is an isoparametric element based on Timoshenko beam theory. The proposed smart beam finite element is applied to the free vibration control adopting a constant gain feedback scheme. The electrical force vector, which is obtained in deriving an equation of motion, is the control force equivalent to that in existing literature. Validity of the proposed element is shown through comparing the analytical results of the verification examples with those of other previous researchers. With the use of smart beam finite elements, simulation of free vibration control is demonstrated by sensing the voltage of the piezoelectric sensors and by applying the voltages to the piezoelectric actuators.

• 한국식품영양과학회지
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• 제23권6호
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• pp.1027-1031
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• 1994

A method for the process of making fig conserves to prevent the denaturation of ficin (EC3.422.3) that is a proteolytic enzyme in fig (Fixus carica L. ) has been developed. The suutable composition ratio of materials such as, fig, sugar, citric acid and potassium sorbate, to make fig conserves was 1,000, 600 , 1.0 and 0.67g , respectively. to maintain the ficin activity, it was necessary that these materials were heated on 55$^{\circ}C$ and concentrated in the reduced pressure. At a result of sensory evaluation , meat treated with fig was the softest among samples. Then the treated beef with 55$^{\circ}C$ converse, 7$0^{\circ}C$ conserves, sugar and control have been shown the decreased rate respectively. There was significantly different in the effect of tenderness between each group(0.1%) . The nitrogen content of connective tissue was relatively low in the groups of the treated beef with fig and 55$^{\circ}C$ converses, 7$0^{\circ}C$ converses sugar and control , which was similar to the order of the ficin activity. This research revealed that the constituent protein of meat muscle was decomposed by ficin and its solubility was relatively higher than before.

• 환경위생공학
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• 제6권2호
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• pp.17-31
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• 1991

The effects of environmental agents on health are great concern for all. It was recognized that each human has differential susceptibility to environmental effects. Susceptibility are changed by many factors includin gdevelopmpntal processes, genetic factors, nutritional stratus, preexisting disease conditions, life style and personal habits. Of all factors nutritional factors seem to be the area most modifiable. Consequently, It is an area that must be more thoroughly evaluated. In this paper, nutrient and environment interactions are reviewed briefly with published literatures. This paper deals with the influence of micronutrients(energy, protein and fat), Vitamins (vitamin 4, vitamin B-complex, vitamin C, vitamin D and vitamin I) and Minerals(calcium, iron, selenium, zinc and other minerls) on environmental effects. The role of arch nutrient was assessed in modifyine the expression of environmental pollutant toxicity with available litertures. In each nutrient section, the effect of environment was considered in following agents : heavy metals(lead, cadmium, mercury, silver and etc), inorganic agents(nitwits, sulfite, fluoride and etc), organic agents(benzene, carbon tatra-chloride, aflatoxin, auto dye, dialbrin etc), Irritant gas(ozone, carbon monooxide and etc), physical agents(X-irradiation, ultra violet, temperature and noise) and insectcides. The extent to which nutritional status modifies environmental effects 3nd its converse, how envirollments affects nutritional status is very complex. In deed, at the present time there are more than 50 chelnical/phycical agents that affect the nutrient metabolism and/or have their toxicity either directly diminished or enhanced by nutrients of those agents, small number of agents for each nutrients have sufficient evidence to warrant any reasonable degree of confidence in their hypothesized associtation. With these information at this present time it is hard to conclude that the recommended dietary allowance for each nutrient should be reconsidered.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.2050-2052
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• 2000

In this paper, the effect of $O_2$ concentration on NO removal and $NO_2$ generation by corona discharge from simulated flue gas was measured and estimated for the wire-plate reactor. $NO_2$ removal rate was 0$\sim$30[%] under about 3.4[%] of oxygen concentration, however, it was difficult to remove NOx over 3.4[%] of oxygen concentration. It may be due to generate $NO_2$ from $N_2$ and $O_2$ molecules and converse NO to $NO_2$ by 0 and $O_3$. Magnetic field applied to electric field in plasma was very effective for NOx removal under 2[%] of $O_2$ concentration.

• 한국기계기술학회지
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• 제13권2호
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• pp.123-128
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• 2011

It has been stand high in estimation to converse from Carbon dioxide to Dimethyl Ether in new alternative fuel energy division in 21C, especially Using of DME in point of view of transportation fuel has been discussed of a new clean energy which is very lower of exhaust gas than gasoline and diesel energy. In this paper it is used ZSM-5 and I developed new catalyst by addition of cerium to control acidity. The new catalyst was proved high conversion rate, when it was conversed from methanol to DME, there wasn't any additional material except DME and water, and I overlooked reaction temperature, reaction time, amount of catalyst, amount of added cerium, effect of water content in methanol, reaction temperature by making change of reaction time. I have conclude that conversion rate to DME was increased as increased of catalyst amounts. The best catalyst condition of without additional product was treated poisoning from ZSM-5 to 5% cerium and new catalyst was not effected in purity of fuel methanol.

• 한국전산구조공학회논문집
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• 제16권2호
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• pp.183-195
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• 2003

본 연구에서는 판형태의 압전감지기와 압전작동기가 접착되어 있는 보형태의 스마트구조물의 자유진동제어에 대한 유한요소모형화 방법을 제안한다. 압전재료의 직접압전효과와 역압전효과에 대한 구성방정식을 고려하고 변분원리를 이용하여 스마트보유한요소의 운동방정식을 유도한다. 이러한 2절점 보 유한요소근 등매개변수요소로서 Timoshenko 보이론을 기초로 한다. 따라서, 보형태의 스마트구조물을 제안하는 스마트보 유한요소에 의하여 해석함으로써 전압이 작용되는 압전작동기에 의한 구조물의 제어와 전압을 측정하는 압전감지기에 의한 구조물의 모니터링에 대한 수치적인 시뮬레이션이 가능해진다 이러한 스마트보유한요소와 Constant-gain feed back control 기법을 이용하여 압전감지기와 압전작동기를 이용한 보구조물의 자유진동제어에 대한 유한요소 모델을 제안한다

• 농촌계획
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• 제22권4호
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• pp.103-114
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• 2016

The global trade partners have been diversified and mixed in agricultural market, which is expended the international agri-food market through the Regional Trade Agreement and World Trade Organization, etc. The aim of this study is to derive influential factors for exports increases of agricultural products targeting to Association of South-East Asian Nations (ASEAN). We set the equation for agricultural products exports referred to panel gravity model considering panel fixed effect for controlling endogeneity within variables. The results of this study are the follows; (1) Social economic distance considering international oil price negatively affects in the mushroom model; (2) Korean GDP affects (-) in a mushroom model and (+) in a vegetable model, however, ASEAN's per capita GDP indicates opposite influence in the same model; (3) Relative exchange rate shows negative impact in a vegetable model; (4) The entry status into WTO and the status in force of FTA have converse effects in mushroom and vegetable model, respectively.

• 한국세라믹학회지
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• 제41권5호
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• pp.406-409
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• 2004

교류 구동 분산형 EL(ACPEL)에 사용되는 ZnS:Cu 청색 형광체를 고상 반응법으로 제조하였다. 1차 소성 후 인위적 결함을 형광체 표면에 도입함으로서 2차 소성 중에 의해 일어나는 ZnS의 상전이 및 EL 발광 휘도에 미치는 영향을 연구하였다. 즉 1차 소성된 형광체를 ball-mill 공정에서 인위적으로 표면에 defect를 형성시켜 ZnS의 저온상인 cubic으로의 전이가 용이하게 하여 EL구동하에서 발광 휘도를 증가시켰다. Ball-mill의 공정 변수로는 milling 시간과 rpm 등을 고려하여 각 조건에 따른 효과를 고찰하였으며, 발광 spectrum을 측정한 결과, 최적 조건에서 인위적인 결함을 형성하지 않은 형광체 보다 발광 휘도가 약 30% 이상 증가하였다. 또한 각기 다른 ball-mill 조건으로 합성된 형광체의 결정상을 분석하고 비교하였으며 상전이 특성에 따른 발광 휘도 변화를 고찰하였다.