• Quality Improvement in Health Care
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• v.5 no.2
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• pp.258-276
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• 1998

This study was conducted to justify the "prescribed shelf life" currently used in Samsung Medical Center and give recommendations based on scientific data to adopt for safe and cost-effective storage times for sterile goods Since the early 1970's, predetermined expiration dating policy has been used in Korea on all in-house sterilized products like any other countries; six months for the supplies wrapped in polyethylene peel pouches and two weeks for the rest. Recently, however, the studies suggest that current standards for preserving the sterility can be changing. It looks like we unnecessarily have too-short expiration date of sterilized supplies, that is far from being cost effective. Certainly, this research is an exciting project, especially in Korea, and will be leading and contributing to the paradigm shift of the conservative concept of shelf life for sterile supplies in Korean healthcare facilities. The major goal of this study was placed on the measurement of the recontamination time in packs wrapped in all kinds of wrapping materials used in S.M.C and stored in various conditions for periods ranging from three months to six months, and then develop a practical standard of "shelf life" based on the analyzed data. Objectives: To measure and compare the recontamination time of sterile packs among wrapppers and storage conditions, and develop a practical standard for the shelf life and storage conditions of sterile products. Samples and Method: The sterile integrity was investigated of the total 1,440 sterile sample packs containing gauze strip($1.5cm{\times}0.5cm$) we prepared and wrapped in nine wrapping materials (randomized reprocessed linens, linens reprocessed 99 times, linens reprocessed 120 times, new kraft paper, used kraft paper, new nonwoven fabrics, 6-time reprocessed nonwoven fabrics, new polyethylene peel pouches, used polyethylene peel pouches), and stored in four locations(closed cabinet of one of the typical wards, open shelf of one of ICUs, open shelf of separate storage room in ER, open shelf in OR), for three to six months, respectively in 1998. Each type of packs were opened weekly and the gauze strips inoculated into Brewer's thioglycollate broth at $35^{\circ}C$ for seven days. Results: There was no growth found for any types of the pack and storage conditions studied. Discussion: This study was conducted in an attempt to identify the possibility of extending the current shelf life for sterile goods we use in a sense of cost effectiveness. The findings suggest that we could extend our expiration dates, that means we can save a lot of materials and personnel time meeded for resterilizing, outdating, recleaning, wrapping, and reshelving. Then it will initiate a great reform in the field of healthcare in Korea, and now we are looking forward to this valuable revolution. We are going to continue this study and take all steps need to apply this new concept to our practice, and then trying to extend to other hospitals.

• Journal of Korea Water Resources Association
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• v.47 no.10
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• pp.973-983
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• 2014

This study focused on the selection of appropriate plant species of VFS (vegetative fiter strips) and the assessment of VFS effects for reducing NPS (non-point source) pollution from uplands. The experimental field was constructed with 1 control and 6 treated plots in the upland area of $1,500m^2$ with 5% slope which is located in Gunwi-gun, Gyeongbuk province. Six vegetation including Chufa, Common crabgrass, Barnyard grass, Turf grass, Tall fescue, Kenturky bluegrass, were applied to install VFS systems during the study period from June 2011 to Dec. 2012. The results of this study showed that 6.1~77.8% in runoff and 15.6~90.3% in TS, 49.9~96.6% in T-P, and 6.7~91.1% in T-N were reduced from the VFS treated plots. Generally high reduction effects were observed from TS, T-P, T-N, and SS, while BOD, TOC, and $NO_3^-$ showed low reductions. The best vegetation type was Turf grass showing higher reduction effects of NPS pollutions and having relatively easier maintenance efforts compared to other vegetations selected in this study. Based on these results, VFS technique found to be an effective management practice for reducing agricultural NPS pollutions in Korean upland conditions. Further study needs to be performed through various field experiments with long term monitoring in order to develop a design manual of VFS system for practical applications.

• Journal of agricultural medicine and community health
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• v.5 no.1
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• pp.5-15
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• 1980

The first recorded trypanosomiasis epidemic in Uganda took place at the beginning of this century in the islands and in a strip along the northern shores of Lake Victoria, which resulted in deaths of 1/3 million people. The disease was partly controlled by early 1930's and continued to occur sporadically in certain localized foci. The disease has however flared up in an explosive outbreak in Busoga district along Lake Victoria since 1977. The incidence of disease in northern district adjacent to Southern Sudan is also increasing lately. This paper describes the three month observation on the surveillance and control activities in the epidemic areas and of various health units including the Vector Control Division, the Tsetse fly Control Division, Tororo Trypanosomiasis Research Institute, medical units in Busoga, and Acholi districts. Data analysis and review were made of disease information so far collected by various health units in the Ministry of Health and district health offices. The findings may be summarized in the following: 1) A total of 12, 100 patients and 38 deaths: have occured in Busoga district since 1977 onward, and over 100 cases of diseases arc occuring in the Northern region bordering Southern Sudan. 2) the distribution of trypanosomiasis is characterized with two district patterns. The disease caused by Trypanosoma rhodesiense occurs in Busoga and is transmitted by Glossina palpalis, G. fuscipes infested in the islands and in the northern shore of forests of Lake Victoria. Another type caused by Trypanosoma gambiense occurs in Madi and Acholi in the north and is transmitted by Glossina morsitans in Savannah. 3) The house survey in Rusoga indicated that most of patients keep domestic animals in their house premises, and are engaging in either farming or fishing. Practically all the patients remembered that they had been bitten by tsetse in the field. 4) The routine diagnostic methods in the hospital laboratory is carried out through the microscopic examination of trypanosome with Giemsa stain of blood and cerebro-spinal fluid, The measurement of ESR and IgM has been used by Tororo Tryponosomiasis Research Institute for field screening.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.3
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• pp.285-292
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• 2016

In this study, FE-BE direct coupling methods of 1D and 2D problems are considered for the pontoon-type floating structure and the difference of the modeling dimensions is investigated for the hydroelastic response. The modeling dimensions are defined as the 1D problem consisting 1D beam-2D fluid coupling and the 2D problem consisting 2D plate-3D fluid coupling with zero-draft assumption. For case studies, hydroelastic responses of the 1D Problem are compared to those of the 2D Problem for a wide range of aspect ratio and regular waves. It is shown that the effects of the elastic behavior are increased by decreasing the incident wavelength, whereas the effects of the rigid behavior are increased by increasing the incident wavelength. In 2D problem, the incident wave angle can be considered, and slightly more accurate results can be obtained, but the computational efficiency is lower. On the other hand, in 1D problem with plate-strip condition, the incident wave angle cannot be considered, but when the aspect ratio is large, the overall responses can be analyzed through a simplified model, and the computational efficiency can be improved.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.9
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• pp.886-894
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• 2014

A wideband bow-tie antenna fed by wideband microstrip-coplanar stripline(CPS) balun and band notch structures that can be applied to bow-tie antenna are proposed in this paper. In order to increase bandwidth, bow-tie radiators are reshaped so that the surface current flows continuously, and wideband impedance matching is achieved by adjusting strip width and spacing of CPS feeding line. The VSWR is measured as 2:1 over the wide frequency range of 2.3~12 GHz. The fabricated antenna size is $60mm{\times}60mm$. In order to achieve the band-notch function at WLAN(5.8 GHz), ${\lambda}/4$ folded-slits located ${\lambda}/4$ away from feeding point are utilized. To minimize the slit size, folded-slit type is adopted. The measured VSWR is 7:1 and gain attenuation is 14 dB at 5.8 GHz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.1
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• pp.79-86
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• 2008

This paper presents to improve of isolation characteristics between personal communication service(PCS) antenna In mobile terminal and 2-channel multi input multi output(MIMO) antenna in the wireless broadband Internet(WiBro) band. In order to improve the isolation between each channel antenna, the proposed PCS antenna with an air space of 3 mm height is located on the projected ground plane($25{\times}12mm$) which is very small space$(0.19{\lambda})$ between the 2-channel WiBro-MIMO antenna. The proposed PCS antenna structure is a modified planar inverted F antenna (PIFA) of spiral type with shorting strip line(6${\times}$4 mm). The calculated Isolation values between the proposed PIFA with 3-dimensional structure and the MIMO antenna at Wibro band are about -20dB below and agree well with the measurement. Measured return loss, bandwidth, and gain o# the proposed antenna are -20dB at 1.8GHz, 110MHz(1.76${\sim}$1.87 GHz) band at -10dB below, and 0.05dBi, respectively, Moreover, we confirm that the proposed PCS antenna has no influence on performance and characteristics of the conversional 2-channel WiBro-MIMO antenna.

• Applied Microscopy
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• v.36 no.3
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• pp.227-234
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• 2006

To investigate the comparative effect of spherical and aspherical RGP lens were worn during 3 weeks on rabbit's cornea. Four white rabbits were worn right eyes with spherical lens and 4 white rabbits were worn right eyes with aspherical RGP lens. Left eyes were served as control. The rabbits were sacrificed at 3 weeks after fitting and observed morphological changes by scanning electron microscopy and also investigate proliferation rate of the corneal epithelium with RGP wearing. After spherical RGP lens wearing, the epithet layer damaged compared to aspherical lens. The superficial cell layer strip off seriously, cell size significantly changed abnormal. Both spherical and aspherical RGP lens fitting group showed so many bacteria and back surface of lens was found like a fern shape. The aspherical RGP lens original material type was some formal than spherical lens. We thought that these pattern was significantly altered with spherical lens by prohibited transmitter oxygen from atmosphere therefore the epithelium shape was changed. This suggested wearing the aspherical lens might be less physiologic than shperical lens fitting.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.46 no.6
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• pp.28-37
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• 2009

In this paper, we propose an obstacle localization method using a road feature based on a V-disparity map binarized by a maximum frequency value. In a conventional method, the detection performance is severely affected by the size, number and type of obstacles. It's especially difficult to extract a large obstacle or a continuous obstacle like a median strip. So we use a road feature as a new decision standard to localize obstacles irrespective of external environments. A road feature is proper to be a new decision standard because it keeps its rough feature very well in V-disparity under environments where many obstacles exist. And first of all, we create a binary V-disparity map using a maximum frequency value to extract a road feature easily. And then we compare the binary V-disparity map with a median value to remove noises. Finally, we use a linear interpolation for rows which have no value. Comparing this road feature with each column value in disparity map, we can localize obstacles robustly. We also propose a post-processing technique to remove noises made in obstacle localization stage. The results in real road tests show that the proposed algorithm has a better performance than a conventional method.

• Restorative Dentistry and Endodontics
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• v.25 no.1
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• pp.109-115
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• 2000

This study was designed to evaluate the microhardness of restorative composite resin and dual-cured composite resin cement which were light cured through the 1.5mm thickness composite overlay. For restorative materials, Z100 and Tetric Ceram were used. For dual cured composite cements, Variolink II((VL II) of three consistency (low, high, ultra high) were used. To determine the optimal microhardness of Z100, Tetric Ceram and Variolink II, each material was packed into the 1mm thickness teflon mold without composite overlay and light cured for 60 seconds. Then the microhardnesses of each sample were measured, averaged and regarded as optimal hardness of each material. To evaluate the microhardness of restorative composite resin and dual-cured composite resin cement which were light cured through the 1.5mm thickness composite overlay, the composites were packed into 1mm thickness teflon mold, coverd with celluloid strip, and then precured composite overlay which was made of Targis(Ivoclar/Vivadent, Liechtenstein) was positioned. 2 types of visible light curing machine, the power density of one of which was 400$mW/cm^2$ and the other was 900$mW/cm^2$, and one type of argon laser were used to cure the restorative composite and dual cured cement. For each group, 10 sample were assigned. The light curing tip was positioned over the composite overlay and light cured for 1min., 2min. or 3min with visible light curing machine or 15sec, 30 sec, 45sec, and 60 sec with argon laser. The Vickers hardnesses of upper and lower surface of Z100, Tetric Ceram, and 3 types of VL II cement were measured. When the 900 $mW/cm^2$ curing light was used, 2min. was needed for optimal curing of Z100 and Tetric Ceram. Variolink II did not be cured optimally even though the curing time was extended to 3min. When 400$mW/cm^2$ curing light was used, 3min. was necessary for Z100, whereas 3min. was not enough for Tetric Ceram. Variolink II was not cured optimally even though the curing time was extended to 3min. When argon laser was used, Z100, Tetric Ceram and Variolink II were not cured optimally in 60 seconds.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.594-601
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• 2019

A true MSEW abutment is an abutment type that directly supports the load of a superstructure. Metal strips, which are in-extensile reinforcements, should be used to minimize abutment deformation. A study to derive the application conditions of a True MSEW abutment was carried out by Zevogolis(2007). As a result, the pullout factor of safety of the uppermost reinforcement was estimated to be the smallest. Therefore, the pullout factor of safety of the uppermost reinforcement is the most important design factor. Parameter analysis was conducted with the abutment length, abutment heel, and abutment height as variables. The pullout factor of safety increased with increasing abutment length and abutment heel length. This is because the contact area increases and the superstructure is dispersed as the abutment length and abutment heel length increase. The pullout factor of safety converges at an abutment length of 1.2m and an abutment heel length of 0.9m. This is because the effective length of the reinforcement is reduced due to the increase in contact area. On the other hand, the extension of the superstructure will increase if the abutment length and abutment heel length are increased excessively. In addition, earth-volume is increased if the abutment height increases excessively. This acts as an upper load on the MSE wall. Therefore, it needs to be examined carefully.