Publications by authors named "Il Bum Kwon"

The purpose of this study was to develop an ICT-based care-management support system and to assess its validity and applicability through pilot testing. The system links users' health and social needs to community resources. Users and care managers participated in each step of care management through an interactive decision support system.

View Article and Find Full Text PDF

We developed a comprehensive health and social-need assessment system to evaluate the diverse needs of elders with chronic illnesses in the community and to enhance the connection of their needs to health and social services. A comprehensive needs-assessment tool and profiles were integrated into the ICT system. We found that care managers could assess elders' needs comprehensively and connect those needs to suitable health and social services systematically.

View Article and Find Full Text PDF

We present a fiber-optic multibeam Mach-Zehnder interferometer (m-MZI) for simultaneous multi-parameter measurement. The m-MZI is comprised of a section of photonic crystal fiber integrated with two independent cores of distinct construction and birefringence properties characterized for torsion, strain and temperature sensing. Due to the presence of small core geometry and use of a short fiber length, the sensing device demonstrates inter-modal interference in the small core alongside the dominant inter-core interference between the cores for each of the orthogonal polarizations.

View Article and Find Full Text PDF

We propose a distributed residual strain sensor that uses an Al-packaged optical fiber for the first time. The residual strain which causes Brillouin frequency shifts in the optical fiber was measured using Brillouin optical correlation domain analysis with 2 cm spatial resolution. We quantified the Brillouin frequency shifts in the Al-packaged optical fiber by the tensile stress and compared them for a varying number of Al layers in the optical fiber.

View Article and Find Full Text PDF
Article Synopsis
  • New fiber Bragg grating (FBG) sensor probes are developed to measure the maximum tensile strain in composite materials for structural health monitoring.
  • The probes consist of thin aluminum films attached to FBG optical fibers, which capture residual strains that reflect the composite materials' strain levels.
  • Two sensor types are tested with different aluminum thicknesses (18 μm and 36 μm), revealing that the 36 μm probe has higher strain sensitivity (0.23) compared to the 18 μm probe (0.13).
View Article and Find Full Text PDF

The use of a fiber optic quasi-distributed sensing technique for detecting the location and severity of water leakage is suggested. A novel fiber optic sensor probe is devised with a vessel of water absorption material called as water combination soil (WCS) located between two highly reflected connectors: one is a reference connector and the other is a sensing connector. In this study, the sensing output is calculated from the reflected light signals of the two connectors.

View Article and Find Full Text PDF

A novel method for auto-correction of fiber optic distributed temperature sensor using anti-Stokes Raman back-scattering and its reflected signal is presented. This method processes two parts of measured signal. One part is the normal back scattered anti-Stokes signal and the other part is the reflected signal which eliminate not only the effect of local losses due to the micro-bending or damages on fiber but also the differential attenuation.

View Article and Find Full Text PDF

Stimulated Brillouin scattering in optical fibers can be used to measure strain or temperature in a distributed manner. Brillouin optical time domain analysis (BOTDA) is the most common sensor system based on the Brillouin scattering. To improve the spatial resolution of these measurements, shorter pulses must be used, resulting in reduced signal powers causing a decrease of the dynamic range.

View Article and Find Full Text PDF

This paper describes a fiber optic sensor suitable for noncontact detection of ultrasonic waves. This sensor is based on the fiber optic Sagnac interferometer, which has a path-matched configuration and does not require active stabilization. Quadrature phase bias between two interfering laser beams in the Sagnac loop is applied by controlling the birefringence using a fiber polarization controller.

View Article and Find Full Text PDF