• Journal of Electrochemical Science and Technology
• /
• 제12권2호
• /
• pp.230-236
• /
• 2021

Ionic conduction mechanism of Mg-Al layered double hydroxides (LDHs) intercalated with CO₃^2- (Mg-Al CO₃^2- LDH) was studied. The electromotive force for the water vapor concentration cell using Mg-Al CO₃^2- LDH as electrolyte showed water vapor partial pressure dependence and obeyed the Nernst equation, indicating that the hydroxide ion transport number of Mg-Al CO₃^2- LDH is almost unity. The ionic conductivity of Mg(OH)₂, MgCO₃ and Al₂(CO₃)₃ was also examined. Only Al₂(CO₃)₃ showed high hydroxide ion conductivity of the order of 10^-4 S cm^-1 under 80% relative humidity, suggesting that Al₂(CO₃)₃ is an ion conducting material and related to the generation of carrier by interaction with water. To discuss the ionic conduction mechanism, Mg-Al CO₃^2- LDH having deuterium water as interlayer water (Mg-Al CO₃^2- LDH(D₂O)) was prepared. After the adsorbed water molecules on the surface of Mg-Al CO₃^2- LDH(D₂O) were removed by drying, DC polarization test for dried Mg-Al CO₃^2- LDH(D₂O) was examined. The absorbance attributed to O-D-stretching band for Mg-Al CO₃^2- LDH(D₂O) powder at around the positively charged electrode is larger than that before polarization, indicating that the interlayer in Mg-Al CO₃^2- LDH is a hydroxide ion conduction channel.

• 대한전기학회논문지:시스템및제어부문D
• /
• 제54권10호
• /
• pp.615-619
• /
• 2005

Token coherence protocol has many good reasons against snooping/directory-based protocol in terms of latency, bandwidth, and complexity. Token counting easily maintains correctness of the protocol without global ordering of request which is basis of other dominant cache coherence protocols. But this lack of global ordering causes starvation which is not happening in snooping/directory-based protocols. Token coherence protocol solves this problem by providing an emergency mechanism called persistent request. It enforces other processors in the competition (or accessing same shared memory block, to give up their tokens to feed a starving processor. However, as the number of processors grows in a system, the frequency of starvation occurrence increases. In other words, the situation where persistent request occurs becomes too frequent to be emergent. As the frequency of persistent requests increases, not only the cost of each persistent matters since it is based on broadcasting to all processors, but also the increased traffic of persistent requests will saturate the bandwidth of multiprocessor interconnection network. This paper proposes a new request mechanism that defines order of requests to reduce occurrence of persistent requests. This ordering mechanism has been designed to be decentralized since centralized mechanism in both snooping-based protocol and directory-based protocol is one of primary reasons why token coherence protocol has advantage in terms of latency and bandwidth against these two dominant Protocols.

• Transactions on Electrical and Electronic Materials
• /
• 제13권6호
• /
• pp.273-277
• /
• 2012

The vacuum drying process for drying of paper in current transformers was modeled with an aim to develop an understanding of the drying mechanism involved and also to predict the water collection rates. A molecular as well as macroscopic approach was adopted for the prediction of drying rate. Ficks law of diffusion was adopted for the prediction of drying rates at macroscopic levels. A steady state and dynamic mass transfer simulation was performed. The bulk diffusion coefficient was calculated using weight loss experiments. The accuracy of the solution was a strong function of the relation developed to determine the equilibrium moisture content. The actually observed diffusion constant was also important to predict the plant water removal rate. Thermo gravimetric studies helped in calculating the diffusion constant. In addition, simulation studies revealed the formation of perpetual moisture traps (loops) inside the CT. These loops can only be broken by changing the temperature or pressure of the system. The change in temperature or pressure changes the kinetic or potential energy of the effusing vapor resulting in breaking of the loop. The cycle was developed based on this mechanism. Additionally, simulation studies also revealed that the actual mechanism of moisture diffusion in CT's is by surface jumps initiated by surface diffusion balanced against the surrounding pressure. Every subsequent step in the cycle was to break such loops. The effect of change in drying time on the electrical properties of the insulation was also assessed. The measurement of capacitance at the rated voltage and one third of the rated voltage demonstrated that the capacitance change is within the acceptance limit. Hence, the new cycle does not affect the electrical performance of the CT.

• 자원환경지질
• /
• 제24권3호
• /
• pp.287-299
• /
• 1991

The study area is mainly composed of metasedimentary rocks which are included in Ogchon, Choson and Pyongan Groups. Because of thrust faults which are developed in this area, a coal bearing formation is repeatedly distributed two times, and Choson Group is thrusted over Pyongan Group. Deformation in this area was taken place in a series of three phases ($D_1$, $D_2$ and $D_3$) ; $D_1$ was most intense whereas $D_3$ was weakest. Thrust faults developed in the upper curst duringD2 produced cataclastic rocks and fault breccia,truncating regional slaty cleavage and earlier folds which were formed during $D_1$ stage. The quartz microstructures of metapsammitic rocks in Choson and Pyongan Groups suggest that dislocation creep mechanism predominated early in fabric development, afterwards deformation mechanism was transfered to pressure solution which intensified the earlier fabrics. According to strain analysis using quartz grains and quartz aggregate grains, the strain magnitude(Es) of Pyongan Group represents larger values than that of Choson Group due to the contrast of constituent minerals, the size of original quartz grains and matrix content. Apparent flattening type in strain pattern appears in the whole area. It is suggested that the relationship between Ogchon Group and Choson Group may be thrust contact.

• Journal of Multimedia Information System
• /
• 제9권2호
• /
• pp.127-136
• /
• 2022

In MMORPGs, there are many problems with the Grinding player experience. This research divides the Grinding player experience into four dimensions: Grinding in-Autonomy, Competence, Relatedness and Positive affect through theoretical investigation of game experience. Through the study of Litman (2008), Curiosity is divided into two dimensions, I-Type Curiosity and D-Type Curiosity, and the relationship between Curiosity and Grinding player experience is studied. By distributing questionnaires, collecting data, and using SPSS software to conduct reliability analysis, validity analysis, correlation analysis and multiple regression analysis on the data, it is verified that in MMORPG, I-Type Curiosity can positively affect Grinding in-Autonomy, Competence, Relatedness and Positive affect. D-Type Curiosity can positively affect Grinding in-Autonomy, Competence and Positive affect, but D-Type Curiosity has no statistical relationship with Grinding in-Relatedness. And through the standardized coefficient (Beta) value, between the Curiosity factors, I-Type Curiosity has a greater impact on Grinding in-Autonomy and Positive affect, and D-Type Curiosity has a greater impact on Grinding in-Competence. Finally, from the perspective of I-Type Curiosity and D-Type Curiosity, combined with the drawbacks of the MMORPG Gringding mechanism, some concrete and feasible suggestions and optimization schemes are put forward to improve the Grinding player experience. This research result can provide some feasible suggestions for MMORPG developers and designers, optimize the MMORPG Grinding mechanism from the perspective of I-Type Curiosity and D-Type Curiosity, and improve the Grinding player experience. It can provide appropriate assistance for the improved development of MMORPG games.

• 대한기계학회논문집B
• /
• 제39권11호
• /
• pp.871-884
• /
• 2015

유체이송 기술은 마이크로 유체시스템 개발에서 핵심문제로 인식되고 있다. 최근 명(2014)은 외부동력을 사용하지 않고 액적을 이동시킬 수 있는 새로운 개념을 제안하고, 초기에 반원통형 형상을 가지는 가상의 2차원 액적에 대한 수치해석을 통해 이 개념이 성립함을 보였다. 또한 명과 권(2015)은 친수성/소수성 표면위에서 초기 3차원 반구 형상의 실제 물 액적이송의 메커니즘을 시간에 따른 액적형상과 액적 내부의 운동에너지, 중력에너지, 표면자유에너지 및 압력에너지의 수치해석 결과를 통해 규명하였다. 본 연구는 새로운 개념을 확립시키기 위해 초기 구형액적에 대한 3차원 수치해석을 수행하고, 액적이송의 메커니즘을 모세관력 힘의 불균형 관점에서 액적 형상과 다양한 에너지의 수치해석 결과를 통해 규명하였다.

• 한국정밀공학회지
• /
• 제25권5호
• /
• pp.82-88
• /
• 2008

This paper proposes a novel method of 2 dimensional shape display. Shape displays allow us to feel tile actual volume of the object, unlike conventional 2D visual displays of 3D objects. The proposed method employs a wireframe structure to present 2D or 3D objects. The wireframe is composed of small units driven by shape memory alloy (SMA) actuators. The drive unit is analogous to the agonist-antagonist system of animal musculoskeletal systems, where the SMA actuators serve as agonist and antagonist muscles. The force in the SMA actuator is controlled by electrical current. The drive unit is equipped with the locking mechanism so that it can sustain the external force exerted by the user as well as the own weight of the wireframe structure. By controlling the current into the SMA actuator and locking mechanism, we can control the angle of the drive unit. A chain of drive units enables presentation of 2 dimensional objects. 3 dimensional presentations are possible by collecting the chains of drive units.

• KSBB Journal
• /
• 제6권3호
• /
• pp.241-247
• /
• 1991

본 연구에서는 고정전달자를 갖는 poly(4-vinylpyridine-co-styrene) 고분자막을 합성하여 이를 특성화하고, $Cl^-$ 및 $CCl_3COO$ 의 $H^+$ 및 $OH^-$ 농도차에 따른 능동전달 기구에 대하여 고찰하였다. 시험 범위 내에서 $Cl^-$의 능동전달은 주로 $H^+$ 농도차를 구동력으로 한 병류수송(symprot)이 주가 되었으며 반면에 $CCl_3COO^{-}$의 능동전달은 $OH^-$의 농도차에 의한 향류 수성(antiport)의 영향이 큼을 알 수 있었다. $H^+$ 농도와 $OH^-$ 농도에 의한 음이온의 초기플럭스를 관찰함으로서, 고정전달자와 이온간의 엄형성계수, K와 이온의 막내 확산계수, D는 $Cl^-$의 경우 각각 $4.60{\times}10^2\;mol^{-1}{\cdot}\textrm{cm}^3$ 및 $1.57{\times}10^3{\textrm{cm}^2}/h$, $CCl_3COO^{-}$의 경우 각각 $1.10{\times}10^4\;mol^{-1}{\cdot}\textrm{cm}^3$ 및 $1.44{\times}10^4{\textrm{cm}^2}/h$ 이었다.

• Mycobiology
• /
• 제47권2호
• /
• pp.242-249
• /
• 2019

Betaine derivatives are considered major ingredients of shampoos and are commonly used as antistatic and viscosity-increasing agents. Several studies have also suggested that betaine derivatives can be used as antimicrobial agents. However, the antifungal activity and mechanism of action of betaine derivatives have not yet been fully understood. In this study, we investigated the antifungal activity of six betaine derivatives against Malassezia restricta, which is the most frequently isolated fungus from the human skin and is implicated in the development of dandruff. We found that, among the six betaine derivatives, lauryl betaine showed the most potent antifungal activity. The mechanism of action of lauryl betaine was studied mainly using another phylogenetically close model fungal organism, Cryptococcus neoformans, because of a lack of available genetic manipulation and functional genomics tools for M. restricta. Our genome-wide reverse genetic screening method using the C. neoformans gene deletion mutant library showed that the mutants with mutations in genes for cell membrane synthesis and integrity, particularly ergosterol synthesis, are highly sensitive to lauryl betaine. Furthermore, transcriptome changes in both C. neoformans and M. restricta cells grown in the presence of lauryl betaine were analyzed and the results indicated that the compound mainly affected cell membrane synthesis, particularly ergosterol synthesis. Overall, our data demonstrated that lauryl betaine influences ergosterol synthesis in C. neoformans and that the compound exerts a similar mechanism of action on M. restricta.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2012년도 추계학술대회 논문집
• /
• pp.227-228
• /
• 2012