An apparatus for manufacturing a polymer fiber shell from liquefied polymer is provided. The loop carries data and provides power to the field device. The dual antenna includes a feeding portion, a first radiation portion, a second radiation portion, a first grounded portion, a second grounded portion, and a connecting portion. In particular, each user may participate in the conference session through a respective user endpoint in the communications network, where the respective user endpoint may be hosted by and independently executable through at least one service endpoint. Thus, it is possible to suitably control the change in pixel brightness regardless of the polarity of the applied voltage, thereby preventing any fringes from being generated while displaying moving images. It is also intended to provide a novel screening system for a remedy, a preventive or a treating agent for vascular disorders, hypertension and renal disorders with the use of such a transportation system.