Visual contrast modulates maturation of camouflage body patterning in cuttlefish (Sepia pharaonis).

Camouflage is the primary defense behavior in cephalopods. It is known that cuttlefish immediately after hatching are capable of showing various body patterns for concealing themselves, however recent studies suggest that maturation of camouflage body patterns is faster for cuttlefish (Sepia officinalis) reared in enriched environments than those reared in impoverished environments. Since camouflage patterning in cephalopods is predominately visually driven, this study specifically investigates effects of the rearing background contrast on the maturation of body patterns in cuttlefish (Sepia pharaonis). Newly hatched animals were separated into two cohorts, one reared in a uniform-gray background (low-contrast, or L group) and the other raised in a black/white checkerboard background (high-contrast, or H group). At Weeks 2, 4, 6, 8, 10, and 12, cuttlefish were placed individually either on uniform or checkerboard substrates to examine their body patterns. Animals from both L and H groups appear to show moderate disruptive patterns on the checkerboard and less disruptive on the uniform background at Week 2. Throughout development, however, cuttlefish from the H group showed stronger disruptive patterns than that of the L group on the checkerboard background at Weeks 10 and 12. In interesting findings, cuttlefish from both L and H groups showed similar strength but different disruptive components on the uniform background in later postembryonic stages. These results suggest that the maturation of camouflage body patterns in S. pharaonis is at least in part affected by visual contrast of their rearing backgrounds, although environmental complexity or social interaction is also likely to be involved in this process. This also implies that early visual experience could exert its effect on the seemingly preprogrammed behaviors such as camouflage body patterning in cephalopods. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

采用反射式液晶显示器和有机电致发光器件前后双置组合而成的高环境对比度显示器

一种高环境对比度(A-CR)和大开口率的显示器已经从理论上证明,并通过把一个正常显黑反射型显示器(NB-RLCD)和一个有机电致发光器件(OLED)堆垛的实验加以证明。这种前后双置(以下称为tandem型)的器件组合可以分别在明亮或昏暗的环境下切换NB-RLCD模式或OLED模式。RLCD的正常显黑特性也可以提升OLED模式工作时的A-CR性能。为了在RLCD模式下获得更好的图像品质,一个复杂并且具有传输功能的结构被用于消除镜面反射和提高可视角至CR﹥2:1超过55°的锥面可视角度。另外,这样的结构也可以提高OLED49.4%的表面量子效率。在我们的实验里,忽略环境亮度因素并使A-CR保持在100:1以上。     

A high-capacity performance-preserving blind technique for reversible information hiding via MIDI files using delta times

A new high-capacity information hiding method for embedding secret messages into MIDI files is proposed. The method can preserve the original musical performance of the cover MIDI file. The property of the variable-length quantity, which expresses the magnitude of the delta time before every event in a MIDI file, is utilized for secret bit embedding. The embedding is accomplished by padding the delta times with different numbers of leading constant bytes of 80₁₆ to represent the secret bits. The method is both reversible and blind because the original cover MIDI file can be restored completely from the stego-MIDI file by extracting the embedded data out from the resulting stego-MIDI file without referencing the original cover MIDI file. A capability of hiding a large amount of secret information is achieved since the delta time is a basic parameter that appears before every event in the MIDI file. Good experimental results yielded by the proposed method as well as a comparison of the method with five existing performance-preserving methods from the viewpoints of stego-file quality, payload capacity, and data security show the superiority and feasibility of the proposed method.

     

基于生态位理论的国际承包商竞争力研究

基于组织生态学视角,采用2011 年度国际建筑市场顶级225 家承包商数据,对我国的国际承包商生态位及竞争力进行研究。结果表明我国顶级承包商在国际建筑市场上占有重要市场份额,在国际建筑市场的发展上具有举足轻重的地位,实力不断增强,总体来讲处于竞争优势地位;主要涉足领域包括房屋建筑、能源、交通等传统行业,而对于工业和电讯方面涉及较少,处于竞争劣势地位。针对此情况为中国承包商在拓展国际建筑市场方面提供建议。     

Experimental analyses to investigate the feasibility and effectiveness in using heat-pipe embedded end-mills

This study experimentally verifies the feasibility and effectiveness of heat-pipe cooling in end-milling operations. The basic idea is to embed a heat-pipe at the center of an end-mill with the evaporator close to the tool tip, and the condenser at the tool end. Thus, most of heat generated on the end-mill tip can be quickly removed dependent on convection heat transfer by means of heat-pipe. The end-milling experiments were carried out on a CNC vertical machining center under three different cooling conditions, including dry milling, fluid cooling, and heat-pipe cooling. The work material was AISI 1040 steel, and hard alloy was chosen for the cutting tool material. Flank wear is considered as the criterion for tool failure and the wear was measured using a Hisomet II Toolmaker's microscope. The tests were conducted until the end-mill was rejected when maximum flank wear equal to 0.30?mm was recorded. The results validate that heat-pipe-assisted cooling in end-milling processes can effectively perform thermal management comparable to the fluid cooling used pervasively in the manufacturing industry, increasing the service life of the end-mill.     

Experimental analyses to investigate the feasibility and effectiveness in using heat pipe-embedded drills

This paper presents an experimental investigation to verify the feasibility and effectiveness of heat pipe cooling in drilling operations. The basic idea is to insert a heat pipe at the center of the drill tool with the evaporator close to the drill tip and the condenser at the end of the drill. Consequently, the heat generated at the tool–chip interface can be removed by convection heat transfer. Experimental studies were involved in three cases, including solid drill without coolant, solid drill with coolant, and heat pipe drill. Drilling tests were conducted on a CNC machining center with full immersion cutting. The cast iron square block was used as the workpiece, and the high-speed steel was chosen for the drill tool material. Flank wear is considered as the criterion for tool failure, and the wear was measured using a Hisomet II Toolmaker’s microscope. The tests were conducted until the drill was rejected when an average flank wear greater than 0.10?mm was recorded. The results demonstrate that using a heat pipe in the drilling process can effectively perform thermal management comparable to the flooding coolant cooling used pervasively in the manufacturing industry, extending the tool life of the drill.     

Design to suppress return-back leakage current of charge pump circuit in low-voltage CMOS process

A new charge pump circuit has been proposed to suppress the return-back leakage current without suffering the gate-oxide reliability problem in low-voltage CMOS process. The four-phase clocks were used to control the charge-transfer devices turning on and turning off alternately to suppress the return-back leakage current. A test chip has been implemented in a 65-nm CMOS process to verify the proposed charge pump circuit with four pumping stages. The measured output voltage is around 8.8 V with 1.8-V supply voltage to drive a capacitive output load, which is better than the conventional charge pump circuit with the same pumping stages. By reducing the return-back leakage current and without suffering gate-oxide overstress problem, the new proposed charge pump circuit is suitable for applications in low-voltage CMOS IC products.     

用于高对比度反射式显示的扭曲PDLC

开发了一种采用扭曲边界聚合物分散型液晶(TPDLC)的高亮度、高对比度反射式显示器。与普通的PDLC膜相比，TPDLC不依赖于偏振光，具有高的对比度和低的工作电压。还演示了一种利用染料掺杂TPDLC的黑白笔段式字母反射式显示器。     

Prediction of members’ return visit rates using a time factor

The profit of portal companies in Taiwan is generated by online advertising and e-commerce. Effective advertising requires predicting how users respond to advertisements and then targeting (presenting advertisements) the users in ways that reflect their preferences. The behavioral targeting leverages historical users’ behaviors in order to select for display the ads which are most related to the users’ preferences. Although we may not want to provide advertisements that repeat the same concept, we can exploit predicted return visit rates for the registered members at the specific category of a portal site. However, customers’ preferences change over time. In order to capture the ‘concept drift’, we propose a novel and simple time function to increase/decrease the weight of the old data in evaluating various members’ past behaviors. Then, we construct a member’s Click Preference Index with a Time factor (CPIT) model in order to effectively distinguish the different kinds of member behaviors and predict return visit rates. The marketers of a portal site can thus target the members with high return visit rates and design corresponding marketing strategies. Experimental results with a real dataset have demonstrated that this CPIT model can be practically implemented and provide satisfactory results.