• Journal of the Korean Society of Clothing and Textiles
• /
• v.21 no.4
• /
• pp.750-756
• /
• 1997

The purpose of the study was to investigate a transmittance rate of UVB (Ultraviolet B) through summer fabrics and a protection rate of summer fabric from UVB. The subjects were randomly selected 159 fabrics from Korean common summer fabrics. The protection rates of 159 fabrics from UVB were measured by UVB lamp and UVB sensor, and 14 fabrics among these fabrics were selected for an assay of MTT(3-(4, 5-dimethylthiazol-2-yl) -2, 5 -diphenyltetrazolium). The protection rate of fabrics from cell toxicity of UVB was measured by investigating the difference of the amount of cell toxic substance on between fabrics covered with and without HeLa cell The average protection rate of 159 fabrics from UVB was 95.08%. As result findings, three negative correlations were found between: 1) the transmittance rate of UVB and the amount of MTT on fabrics (y=0.0373+0.O0518 x, r=-0.9323, p<0.001); 2) the air permeability of fabrics and the amount of MTT (r: -0.79, p< 0.01); 3) the air permeability of fabrics and the protection rate of fabrics from UVB (r=0.89, p<0.01). However, there was no effect of thickness of fabrics on the protection rate from UVB and the amount of MTT.

• Bulletin of the Korean Chemical Society
• /
• v.14 no.1
• /
• pp.123-127
• /
• 1993

New lipophilic Crown-4 compounds of 16-membered rings containing furan (neutral carrier,I), tetrahydrofuran (neutral carrier,II) and lithium complex of the latter (neutral carrier,III) have been synthesized and tested as the active sensors for lithium ion in poly(vinyl chloride) (PVC) membrane electrode, in the presence and absence of an anion excluder, tetrakis(4-chloro-phenyl)borate (KTClPB), 2-nitrophenyl phenyl ether (NPPE), tris(2-ethylhexyl)phosphate (TEHP), o-nitrophenyl octyl ether (NPOE), dioctyl adipate (DOA), bis(2-ethylhexyl)adipate (BEHA), di-n-octylphenyl phosphonate (DOPP) were used as plasticizing solvent mediators. The electrode response function had a nearly Nernstian slope of 54-61 mV per decade (25$^{\circ}$C) within the concentration range of $10^{-1}-10^{-4}$ M LiCl and the detection limits for all electrodes were ca. $5{\times}10^{-4}$ M. The response time of the electrode was faster at the higher lithium concentration and the response of the electrode was stable for longer than 6 months. The sensor membranes exhibit improved response times and increased lifetimes as compared to the system described earlier.

• Nuclear Engineering and Technology
• /
• v.54 no.3
• /
• pp.1024-1029
• /
• 2022

Composite scintillation screens on a base of Gd_1.2Y_1.8Ga_2.5Al_2.5O₁₂:Ce (GYAGG) scintillator have been evaluated for neutron detection. Besides the powdered scintillator, the composite includes ⁶LiF particles; both are merged with a binder and deposited onto the light-reflecting aluminum substrate. Results obtained demonstrates that screens are suitable for use with a silicon photomultiplier readout to create a prospective solution for a compact and low-cost thermal neutron sensor. Composite GYAGG/⁶LiF scintillation screen shows a pretty matched sensitivity and γ-background rejection with a widely used ZnS/⁶LiF screens however, possesses forty times faster response.

• Journal of Sensor Science and Technology
• /
• v.7 no.3
• /
• pp.179-187
• /
• 1998

A neutral particle energy analyzer, which has the carbon stripping foil and the $90^{\circ}$ cylindrical electrostatic deflection plate, was designed and constructed for measuring of ion temperature in plasma. The energy calibration and energy resolution were studied in detail for a hydrogen ion at the $0.5{\sim}3.0\;keV$ energy using a duoplasmatron ion source. An energy of hydrogen ion to the deflection plate voltage at the peak ion count rate could be fitted by the expression $E_{o}(keV)$=3.83V(kV). The measured energy resolution, which was about 2 % at the energy of 3.0 keV and 9 % at the energy of 0.5keV, was better for the increased hydrogen ion energy. For the charge exchanged hydrogen atom due to the carbon stripping foil, the energy calibration, energy loss and resolution were measured to the $0.5{\sim}2.0{\mu}g/cm^{2}$ thickness of the carbon stripping foil. An energy of the charge exchanged hydrogen atom as a function of the deflection plate voltage and carbon foil thickness could be fitted by the expression $E_{o}(keV)=(0.53d+4.4){\cdot}V(kV)$. The energy loss was $0.23{\sim}0.89\;keV $ to the $0.5{\sim}2.0{\mu}g/cm^{2}$ carbon foil thickness and the $0.5{\sim}3.0\;keV$ energy of the incident neutral hydrogen atom, it could be fitted by the expression ${\Delta}E=(0.12d+0.27){\cdot}{E_{o}}^{1/2}(keV)$. The measured energy resolution for the neutral hydrogen atom, which was between 7 % and 35 % in this experiment region, was increased for the increasing neutral hydrogen atom energy and the decreasing carbon stripping foil thickness.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.9 no.2
• /
• pp.64-72
• /
• 2004

We measured the vertical profiles of $O_2$, H$_2$S, and pH in sediment pore water beneath marine cage fish farms using a microsensor with a 25 ${\mu}{\textrm}{m}$ sensor tip size. The sediments are characterized by high organic material load. The oxygen consumption, hydrogen sulfide oxidation, and sulfate reduction rates in the microzonations (derived from the vertical distribution of chemical species concentration) were estimated by adapting a simple one-dimensional diffusion-reaction model. The oxygen penetration depth was 0.75 mm. The oxic microzonations were divided into upper and lower layers. Due to hydrogen sulfide oxidation within the oxic zone, the oxygen consumption rate was higher in the lower layer. The total oxygen consumption rate integrated with reaction zone depth was estimated to be 0.092 $\mu$mol $O_2$cm$^{-2}$ hr$^{-1}$ . The total hydrogen sulfide oxidation rate occurring within 0.7 mm thickness was estimated to be 0.030 $\mu$mo1 H$_2$S cm$^{-2}$ hr$^{-1}$ , and its turnover time in the oxic sediment layer was estimated to be about 2 minutes. This suggests that hydrogen sulfide was oxidized by both chemical and microbial processes in this zone. The molar consumption ratio, calculated to be 0.84, indicates that either other electron accepters exit on hydrogen sulfide oxidation, or elemental sulfur precipitation occurs near the $O_2$- H$_2$S interface. Total sulfate reduction flux was estimated to be 0.029 $\mu$mol cm$^{-2}$ hr$^{-1}$ , which accounted for more than 60% of total $O_2$ consumption flux. This result implied that the degradation of organic matter in the anoxic layer was larger than in the oxic layer.

• Journal of Sensor Science and Technology
• /
• v.5 no.2
• /
• pp.37-46
• /
• 1996

This paper describes a system that can be used to recognize unknown materials regardless of the change in ambient temperature by using temperature response curve fitting and fuzzy neural network(FNN). There are problems with a recognition system which utilize temperature responses. It requires too many memories to store the vast temperature response data and it has to be filtered to remove the noise which occurs in experiments. Thus, this paper proposes a practical method using curve fitting to remove the above problems of memories and noise. Also, the FNN is proposed to overcome the problem caused by the change of ambient temperature. Using the FNN which is learned by temperature responses on fixed ambient temperatures and known thermal conductivity, the thermal conductivity of the material can be inferred on various ambient temperatures. So the material can be recognized via its thermal conductivity.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.54 no.7
• /
• pp.93-102
• /
• 2017

Recently increasing usage of smartphones makes the Internet of Things (IoT) a leading technology that can collect and share data through sensor networks and wireless communication such as low-power Bluetooth (BLE). BLE-based application can provide operators more precise information on Automatic Door system by remotely diagnosing the system faults through wireless sensor networks and sensors around the Automatic Door. In this paper, a smart device with extended BLE module is implemented which can monitor and Control the system states and faults remotely without on-site diagnostic. while maintaining system integrity so that increase efficiency of time and costs for system management. We can use the results of this research as a basis in evaluating reliability of data between devices, extending communication module in Controller of obsolete Door systems, and establishing centralized monitoring systems in near future with multi-channel Door Controls.

• Journal of Sensor Science and Technology
• /
• v.27 no.3
• /
• pp.192-198
• /
• 2018

Pulse oximetry is a non-invasive method for monitoring how much oxygenated hemoglobin is present in the blood. The principle of pulse oximetry is based on the red infrared light adsorption characteristics of oxygenated and deoxygenated hemoglobin. Even through the convenience of a pulse oximeter, its weak signal-to-noise ratio against motion artifacts and low perfusion makes it difficult to be accepted by execs devices. Several researchers have suggested the use of an adaptive noise cancellation (ANC) algorithm. They have demonstrated that ANC is feasible for reducing the effects of motion artifacts. Masimo Corporation developed a discrete saturation transformation (DST) algorithm that uses a reference signal and ANC. In commercial devices, it is very hard to escape it because Masimo's patents are very powerful and a better method is yet to be developed. This study proposes a new method that can measure noise saturation as well as accurate oxygen saturation from signals with high motion artifacts without using ANC and DST. The proposed algorithm can extract a normal signal without noise from a signal with motion artifacts. The reference signal from a pulse oximeter simulator was used for the evaluation of our proposed algorithm and achieved good results.

• Journal of Astronomy and Space Sciences
• /
• v.22 no.4
• /
• pp.483-490
• /
• 2005

For an image sensor CCD, electrons can be trapped at the front-side $Si-SiO_2$ surface interface in a case of exceeding the full well by bright source. Residual images can be made by the electrons remaining in the interface. These residual images are seen in the font-side-illuminated CCDs especially. It is not easy to find a quantitative analysis for this phenomenon in the domestic reports, although it is able to contaminate observation data. In this study, we find residual images iB dark frames which were obtained from the front-side-illuminated CCD at Mt. Lemmon Optical Astronomy Observatory (LOAO), and analyze the effect to contaminated observation data by residual charges.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.11a
• /
• pp.440-443
• /
• 2002

Present1y the X-Ray diagnosis system is a real condition that is changing by digital ways in it's existent analog ways. This digital radiation detector is divided by the direct method and the indirect method. The indirect method of applied voltage has special qualities that the resolution is low than direct method by diffusion effect that happens. The conversion process ( radiation${\rightarrow}$visible ray${\rightarrow}$electrical signal of two times, has shortcomings that the energy conversion efficiency of electrical signal is low. The direct method has shortcomings that need strong electric fie1d to detect electrical signal efficiently. This research achieved to develop digital detector of the Hybrid method that have form that mixes two ways to supplement shortcoming of direct. indirect method. A studied electrical characteristic by Iodine's Mixture ratio change is added to selenium in the detector which has a multi-layer structure (Oxybromide + a-Se). There are 8 kinds of Manufactured compositions to amorphous selenium Iodine each 30ppm, 100ppm, 200 ppm, 300ppm, 400ppm, 500ppm, 600ppm, 700ppm by a doped photoconductor through a vacuum thermal evaporation method. The phosphor layer is consisted of Oxybromide ($BrO_2$) which uses optical adhesives multi-layer structure. The manufactured compositions calculates and compares Net Charge and signal to noise ratio measuring Photocurrent about Darkcurrent and X-ray. When doped Iodine Mixture ratio is 500ppm to the multi-layer structure (Oxybromide + a-Se), applied voltage of $3V/{\mu}m$, leakage current of compositions $2.61nA/cm^2$ and net charge value by 764pC/$cm^2$/mR then the best result appeared.