A novel compact quad-band internal antenna for mobile handsets operating the , GPS (1575 Ϯ 10 MHz), DCS (1710 -1880 MHz), and PCS (1850 -1990 bands is proposed and implemented. The proposed antenna consists of a feeding strip, shorting strip, and folded loop radiating element with embedded tuning notches. Embedding the notches changes the current flow on the surface of the loop radiator so that the resonant frequencies can be controlled independently by their size and position. The measured impedance bandwidth (VSWR Ͻ 2) of the proposed antenna is 11.3% at GSM band and 27.4% at higher bands including GPS/DCS/PCS. The measured peak gains are 0.51, 2.06, 0.52, and 1.34 dBi, at the GSM, GPS, DCS, and PCS bands, respectively. ABSTRACT: We describe high-efficiency gratings illuminated by incident lights in the C ϩ L bands as the (de)multiplexers for dense wavelength division multiplexing (DWDM) application. This grating is fabricated in fused silica and replicate in polydimethylsiloxane (PDMS) and polyethylene terephthalate glycol (PETG) with the technology of nanoimprint.
: The Convention on the international regulations for preventing collisions at sea, 1972(COLREGs) defines the collision avoidance principles and various navigation rules for the prevention of collision at sea. In particular, the initial responses to avoid risk of collision are mainly decided by navigation officer's experience and subjective judgement. However, collision accidents could be effectively prevented if the minimum criteria of quantitative initial response are suggested to the junior officers and the cadets who have insufficient sea experience and navigation competency. This study reviewed the COLREGs terms related to the initial response and the existing papers concerned with risk assessment model. A questionnaire survey is also carried out for safe passing distance, degrees of alternating course and initial response distance to avoid collision in accordance with various encounter situations. Base on these results, we propose the proper minimum safe passing distance between the vessels, the initial response distance and required turning angles for alternation in each encounter situations. The suggested criteria of initial response will contribute to the prevention of collision at sea as well as the improvement of gradual navigation technology.
300mm semiconductor manufacturing requires a full automated material handling system (AMHS). AMHS operation is tightly coupled with FAB production. Lot scheduling and dispatching are restricted by movement of material, while decisions for material move also should consider lot status and schedules. Therefore, AMHS should be well coordinated with the lot scheduling and dispatching. For the effectiveness of AMHS operation, following three problems that directly cause the change of the material transportation and storage should be solved. The first problem is the stocker allocation which determines the best stocker considering AMHS status. The second is the WIP balancing between cells by controlling the transport timing. The third is the transport prioritization for maximizing the production productivity. In this research, we propose advanced functionalities and logistics for the three problems to improve the effectiveness of AMHS.
This paper analyzed the J/S of the GPS receiver in sea environment from GPS satellite and GPS jammer.Through the analysis, the operational range and effective radiation power of the GPS jammer could be estimated.In the case of the jammer effective radiation power is higher than the specific value, jammer height mainly resolves the jammer operational range.
In this paper, we present a tunable BPF with a novel structure. The filter is very useful to optimization of low frequency filter performance, because the fiilter has air-coils and tuning screws. This filter also has the merits of light weight and small size in comparison with conventional tunable filter at low frequency. This type filters are especially suitable for switched filter bank due to tuning structure. We designed 4 channel filter bank with two SP4Ts and 4 BPFs using novel structure. Tuning processes were subsequently executed. We obtained satisfactory performances as a result; consequently, the validity of our proposal was proved.
Recently many enterprises are adopting thin-client IT environment for intensifying information security. Besides, the business environment has been facing the globalization and the new information technology renovation such as mobility. Thin client architecture, however, is limited to deal effectively with the demands of enterprise's mobile working environment in terms of information security and work productivity. In order to insure the maximization of business efficiency, it requires that all application must be executed locally unlike server based computing solution. Moreover, it provides the same functionalities as company inside to prevent the disclosure of enterprise confidential data which stored on mobile devices. This paper provides the smart client model that are satisfying these mobile computing requirements.
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