• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2002년도 ITC-CSCC -3
• /
• pp.1455-1458
• /
• 2002

In this paper, we propose a modified CP-AFC(Cross-Product Automatic Frequency Control) algorithm to enhance coherent signal detection for WCDMA reverse link receiver. We introduce a moving average filter at the FDD(Frequency Difference Detector) input to increase the number of cross-products, since pilot symbol in WCDMA is not transmitted continuously. We also add normalization algorithm to overcome the conventional CP-FDD's sensitivity to the variance of input signal amplitude and to increase the linear range of S- curve. For rapid frequency acquisition and tracking, we adopt a multi-stage tracking mode. We applied the proposed algorithm in the implementation of WCDMA base station modem successfully.

• 소성∙가공
• /
• 제31권6호
• /
• pp.394-403
• /
• 2022

In the automotive industry, cold-drawn austenitic stainless steel is commonly used to handle high fuel pressures in gasoline direct injection (GDI) engines. In this study, we analyzed the effects of main process variables such as cross-sectional shape, drawing speed and friction coefficient on the microstructure, hardness and residual stress of the drawn material in the two-step cold drawing process. By changing the cross-sectional shape in the first-step cold drawing, the possibility of improving the shape accuracy or physical properties of the finally cold-drawn fuel rail pressure sensor product was investigated.

• 비교문화연구
• /
• 제23권
• /
• pp.321-349
• /
• 2011

The purpose of this study is to examine slangs used in contemporary Russian. In any kind of social group, there are special jargons used to satisfy special needs of verbal communication and express individual affiliation compared with neighboring parties, apart from standard languages popularized in each society. Some of these jargons belong to a category of common usual language, while others are temporarily popularized but disappear. It is undeniable that these languages are a product of our social language phenomena in addition to the presence of standard language. Thus, it is very essential to investigate and understand these linguistic phenomena as well as standard languages. In this study, Chapter 1 examines the definition of slang as one of most important topic with a view to achieve desired goals hereof. Next, Chapter 2 sets the scope of subjects for this study. Chapter 3 subdivides subjects into each group by topic for analysis within the scope as set in the previous chapter. This analysis gives a basis on which we can understand linguistic phenomena and identify any psychological conditions of people who use languages. This study comes to its conclusions with summary of findings from data collection and analysis.

• 비교문화연구
• /
• 제21권
• /
• pp.189-211
• /
• 2010

The purpose of this paper is to 1)examine the current state of cultural studies in Korea with a focus on recent discourses about its 'crisis' and 2)attempt to find some ways out of these dilemmas in drama/theatre/performance studies. As Raymond Williams redefined 'culture' as 'a whole way of life,' performance studies has expanded the boundary of 'performance' from traditional performing arts onto almost everything that can be studied and analyzed 'as' performance. Performance is not only the final product on display but a whole process that includes training, workshop, and rehearsal of culture. According to Richard Schechner, workshop and rehearsal are the most critical and creative 'liminal' phases that allow traditional knowledge and alternative challenges to coexist in conflict and intentionally delay the final decision by putting itself in a perpetual process. From this view, this essay attempts to find an-no matter how limited and temporary-answer to or a possible exit from political and theoretical aporias of cultural studies.

• 한국통신학회논문지
• /
• 제41권11호
• /
• pp.1417-1419
• /
• 2016

처프 확산 대역 시스템의 전송 성능을 향상시키기 위해서는 처프 신호 사이의 상호 상관 계수를 반드시 고려해야 한다. 본 논문은 단일 사용자 전송을 위한 처프 신호의 상호 상관 계수를 수식적으로 도출하였으며, 이를 기반으로 전송 성능을 향상시킬 수 있는 처프율을 이론적으로 제안하였다. 모의실험 결과, 최적의 상호 상관 계수를 고려했을 때 전송 성능이 향상되었으며, 도출된 이론적인 성능이 모의실험 결과와 동일함을 확인하였다.

• Journal of Applied Biological Chemistry
• /
• 제59권1호
• /
• pp.75-81
• /
• 2016

Glutaraldehyde was used as a cross-linking agent for immobilization of purified ${\alpha}$-amylase from Exiguobacterium sp. DAU5. Befitting concentration of glutaradehyde and cross-linking time is the key to preparation of cross-linking chitosan beads. Based on optimized immobilization condition for ${\alpha}$-amylase, an overall yield of 56% with specific activity of 2,240 U/g on chitosan beads and 58% with specific activity of 2,320 U/g on chitosan-carbon beads was obtained. The optimal temperature and pH of each immobilized enzyme activity were $50^{\circ}C$ and 50 mM glycine-NaOH buffer pH 8.5, respectively. Those retained more than 75 and 90% of its maximal enzyme activity at pH 7.0-9.5 and after incubation at $50^{\circ}C$ for 1 h, respectively. In addition, the immobilization product showed higher organic-solvent tolerance than free enzymes. The mode of hydrolyzing soluble starch revealed that the ${\alpha}$-amylase possessed high hydrolyzing activity. These results indicate that chitosan is good support and has broad application prospects of enzyme immobilization.

• Structural Engineering and Mechanics
• /
• 제56권3호
• /
• pp.369-383
• /
• 2015

In this study, effect of various material hardening models based on Holloman's isotropic, Ziegler's linear kinematic, non-linear kinematic and mixture of the isotropic and nonlinear kinematic hardening laws on springback prediction of titanium alloy (Ti-3Al-2.5V) in a tube rotary draw bending (RDB) process was investigated with presenting the keynotes for a comprehensive step by step ABAQUS simulation. Influence of mandrel on quality of the final product including springback, wall-thinning and cross-section deformation of the tube was investigated, too. Material parameters of the hardening models were obtained based on information of a uniaxial test. In particular, in the case of combined iso-nonlinear kinematic hardening the material constants were calibrated by a simple approach based on half-cycle data instead of several stabilized cycles ones. Moreover, effect of some material and geometrical parameters on springback was carried out. The results showed that using the various hardening laws separately cannot describe the material hardening behavior correctly. Therefore, it is concluded that combining the hardening laws is a good idea to have accurate springback prediction. Totally the results are useful for predicting and controlling springback and cross-section deformation in metal forming processes.

• 소성∙가공
• /
• 제24권3호
• /
• pp.187-193
• /
• 2015

The objective of the current study is to determine cross-sectional profile of intermediate dies in order to improve the plastic strain homogeneity which directly affects not only the dimensional accuracy but also the mechanical properties of final product by redesigning the intermediate dies using the conventional electric field analysis (EFA) method. Initially, the multi-pass shape wire drawing was designed by using the equivalent potential lines from EFA. The area reduction ratio was calculated from the number of passes in multi-pass shape wire drawing but constrained by the capacity of the drawing machine and the drawing force. In order to compensate for a concentration of strain in a region of the cross section of the wire, the process for multi pass wire drawing from initial round material to an intermediate die was redesigned again using the electric field analysis. Both drawing process designs were simulated by the finite element method in which the strain distribution and standard deviation plastic strain of the cross section of drawn wires were examined.

• Nuclear Engineering and Technology
• /
• 제54권8호
• /
• pp.3073-3084
• /
• 2022

The propagation of radiation source uncertainties in spent nuclear fuel (SNF) cask shielding calculations is presented in this paper. The uncertainty propagation employs the depletion and source term outputs of the deterministic code STREAM as input to the transport simulation of the Monte Carlo (MC) codes MCS and MCNP6. The uncertainties of dose rate coming from two sources: nuclear data and modeling parameters, are quantified. The nuclear data uncertainties are obtained from the stochastic sampling of the cross-section covariance and perturbed fission product yields. Uncertainties induced by perturbed modeling parameters consider the design parameters and operating conditions. Uncertainties coming from the two sources result in perturbed depleted nuclide inventories and radiation source terms which are then propagated to the dose rate on the cask surface. The uncertainty analysis results show that the neutron and secondary photon dose have uncertainties which are dominated by the cross section and modeling parameters, while the fission yields have relatively insignificant effect. Besides, the primary photon dose is mostly influenced by the fission yield and modeling parameters, while the cross-section data have a relatively negligible effect. Moreover, the neutron, secondary photon, and primary photon dose can have uncertainties up to about 13%, 14%, and 6%, respectively.

• 유통과학연구
• /
• 제20권8호
• /
• pp.123-133
• /
• 2022

Purpose: As moment-based marketing messages (i.e., messages related to current moments or event), companies put significant investments to distribute TV advertising related to external moments in a retail environment. While the literature offers strong support for the value of distributions of context-based messaging to advertisers, less attention has been given to how to design those messages to effectively communicate across channels. This research adds a new dimension of analysis to the study of advertising context and its cross-channel effects on online consumer behavior. Research Design, Data and Methodology: A system-of-equations Tobit regression model was adopted using data collected from an advertising agency that consists of 1,223 TV ads aired during the Rio Olympics and NCAA, tagging from consumers, and a text analysis. Results: First, TV ads with high centrality of context lead to lower online search behavior and higher online social actions. Second, how brands can design messages more effectively was explored by using product information as a moderator that could improve the impact of context-based TV advertisements. Conclusions: Given that expenses in traditional channels are still one of the biggest channel management decisions, it is critical to understand how consumer engagement varies by design of context-based TV advertising.