ABSTRACT
The South Korean livestock industry has increased in scale and production, generating positive impacts on the national economy. However, livestock externalities, primarily malodor, have subsequently led to increased conflicts between producers and affected communities. This study estimated Korean households' willingness-to-pay (WTP) for government subsidies to help address livestock malodor using a contingent valuation method (CVM) derived from a double-bounded dichotomous choice model. The annual average household WTP was estimated at 29,206 Korean won (KRW) (USD 25). This was slightly higher than the respondents' self-reported average amount of KRW 25,457 (USD 22). The estimated economic value nationally is KRW 628 billion (USD 546 million) annually, for a total of KRW 3.14 trillion (USD 2.73 billion) over a proposed five-year period. The public's estimated WTP can be leveraged to improve livestock management practices, more efficient waste disposal techniques, and improved husbandry methods to address conflicts between producers and surrounding communities.
Subject(s)
Livestock , Refuse Disposal , Animals , Humans , Republic of Korea/epidemiologyABSTRACT
A moisture-insensitive optical fingerprint scanner (FPS) that is based on polarization resolved in-finger light is proposed and realized. Incident visible light, which is selectively fed to a fingerprint sample via a polarization beam splitter (PBS), is deemed to be partially scattered backward by tissues associated with the skin of the finger. The backscattered light is mostly index-guided in the ridge comprising the fingerprint, which has a higher refractive index, and is drastically dispersed in the valley, which is typically filled with water or air and so has a lower index. However, when light reflects directly off the surface of the finger skin, it fundamentally prevents the scanned image from being determined. The proposed FPS produces bright and dark intensity patterns that are alternately created on the surface of the PBS and correspond to the ridges and valleys, respectively. Thus, this method can especially distinguish between a fake synthetic fingerprint and a genuine fingerprint due to its use of in-finger scattered light. The scanner has been rigorously designed by carrying out ray-optic simulations depending on the wavelength, with tissue-induced scattering taken into account. The device was constructed by incorporating a wire-grid type PBS in conjunction with visible LED sources, including blue, green and red. The scanner adopting a blue LED, which exhibits the strongest light scattering, resulted in the best fingerprint image, enabling enhanced fidelity under the wet and dry situations. Finally, a fake synthetic fingerprint could be successfully discriminated.
ABSTRACT
An expanded beam connector (EBC) has been proposed and realized, where a single-mode fiber is seamlessly integrated with a ball lens exhibiting a near-zero back focal length (BFL) so that the incoming small mode exiting the fiber translates into an enlarged collimated beam via the lens. The structural tolerance for the fiber-optic connector is primarily relaxed by relieving the restrictions imposed on the meticulous control of the gap between the lens and the fiber. The EBC has been designed through rigorous ray-optic simulations and then constructed based on a ball lens in LASF35 (n=â¼1.98 at λ=1.3 µm), exhibiting an ultrashort BFL of â¼13 µm. It was practically confirmed that an input mode of a â¼10 µm spot relating to the single-mode fiber could be efficiently converted into a highly collimated beam of a â¼350 µm spot that emanates from the ball lens, leading to a 35-fold beam expansion. The alignment tolerance for the fiber as well as the connector unit was scrutinized with respect to the angular tilt and transverse displacement. The measured insertion loss for the EBC, allowing for no separation between the fiber and ball lens, was slightly over 0.8 dB.
