• Journal of Korean Neurosurgical Society
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• 제60권1호
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• pp.67-74
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• 2017

Objective : The purpose of this study was to investigate the prevalence of and the relevant risk factors for lumbar spondylosis (LS) among middle-aged and elderly rural Korean residents and to explore the association between radiographic LS and lower back pain (LBP) in relation to age and gender. Methods : This community-based, cross-sectional study evaluated 1512 subjects with available radiograph. The prevalence of LBP was obtained using a questionnaire and disability resulting from LBP was measured using a validated Korean version of the Oswestry disability index (ODI). In lumbar spine radiographs, vertebral levels from L1/2 to L4/5 were evaluated for the presence of osteophytes and joint-space narrowing (JSN), and Kellgren-Lawrence (KL) grading was applied. Results : Of 4261 subjects aged 40-79 years, data from 1512 subjects were included. The prevalence of radiographic LS indicated by grade ${\geq}2$ osteophytes and JSN were 53.9 and 15.8%, respectively. Seventy-three percent of subjects had KL grade ${\geq}2$ spondylosis and LBP was present in 36.5% of subjects. Although LS was more common among males, the prevalence of LBP was higher among females. Age, male gender and history of hand or knee arthritis were risk factors for LS. LS was significantly associated with LBP mostly among females over 60 years old and correlated with the ODI after adjusting for age and gender. Conclusion : Our study among rural Korean residents revealed a high prevalence of LS and LBP. The association between LS and LBP was observed mostly among females and LS was significantly correlated with the severity of back pain.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전기물성,응용부문
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• pp.155-157
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• 2006

송전전압이 점차 초고압화되면서 절연체의 유전특성을 개선하여 송전용량을 향상시키고, 절연내력을 높여 케이블 외경을 저감시키려는 시도에 따라 우수한 유전특성 및 절연내력을 갖는 폴리머 절연층과 기계적 특성, 절연유와의 적합성이 우수한 크라프트지의 장점을 혼합시킨 반합성지가 개발되어 전력케이블의 주절연재료로 사용되고 있다. 본 논문은 LS전선이 국내최초로 개발한 400 kV급 반합성지 전력케이블 및 접속함 개발과정 및 이와 관련된 요소기술에 대해 기술하였다. 송전시스템에서 요구되는 유전특성의 반합성지를 설계 제작하여, 기존 크라프트 절연지 대비 유전손실은 50% 수준, 절연내력은 125%이상의 반합성지를 개발하였고, 반합성지 고유의 특성인 팽윤율을 조절하여 케이블을 제조하였다. 반합성지 절연 케이블에 필요한 접속함에서는 보강절연재로 케이블과 동일한 반합성지를 사용하여 전체적인 3기를 감소시키고, 열저항성을 줄이고자 노력하였다. 또한, 접속함 조립공정에 필요한 저온연공법을 개발하여 반합성지에 열적 스트레스를 최소화하였다. 상기 관련기술의 개발 결과로, IEC 60141, AEIC CS2-97 및 NGTS 3.5.1에 근거하여 400 kV급 반합성지 OF 케이블 및 접속함에 대해 국제 공인기관인 KEMA의부터 Type Test을 인증받았다.

• Structural Monitoring and Maintenance
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• 제5권3호
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• pp.379-390
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• 2018

In this paper, a novel and effective damage diagnosis algorithm is proposed to detect and estimate damage using two stages least squares support vector machine (LS-SVM) and limited number of attached sensors on structures. In the first stage, LS-SVM1 is used to predict the unmeasured mode shapes data based on limited measured modal data and in the second stage, LS-SVM2 is used to predicting the damage location and severity using the complete modal data from the first-stage LS-SVM1. The presented methods are applied to a three story irregular frame and cantilever plate. To investigate the noise effects and modeling errors, two uncertainty levels have been considered. Moreover, the performance of the proposed methods has been verified through using experimental modal data of a mass-stiffness system. The obtained damage identification results show the suitable performance of the proposed damage identification method for structures in spite of different uncertainty levels.

• 해양환경안전학회지
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• 제3권1호
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• pp.1-14
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• 1997

This paper describes a series of numerical simulations of colision between a 310, 000 DWT double hull VLCC (struck ship) and three 35, 000, 70, 000 and 105, 000 DWT tankers (striking ships) using LS/DYNA3D. Collisions are assumed to occur at the middle of the VLCC with the striking ships moving at right angle to the VLCC centerline. Striking ship speeds are varied to find a critical speed without failure of inner side shell, and the informations of collision force and absorption energy of each case are also reported. The validation of LS/DYNA3D in this study was made by comparing the result of numerical simulation of LS/DYNA3D with that of double hull tanker grounding experiment by the Carderock Division of Navla Surface Warfare Center (CDNSWC).

• Journal of Communications and Networks
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• 제5권1호
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• pp.19-24
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• 2003

A new code, LS code, was proposed for the IMT-2000 CDMA system. The code has special properties during a specific time interval: 1) perfect autocorrelation, and 2) perfect crosscorrelation. Perfect autocorrelation means maximum autocorrelation for zero time-offset and zero autocorrelation for all other times during a specific time interval. Moreover, perfect crosscorrelation means that the crosscorrelation has zero value during a certain time, you can remove all the MAI within that time. However, the detailed properties of LS code and its exact generation method have been previously unknown. Therefore, we investigate the LS code in regards to its exact generating method, properties, and performances in this paper.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 1999년도 Pre-symposium of the 10th ISWPC Recent Advances in Paper Science and Technology
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• pp.386-389
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• 1999

Amphoteric polymers have brought to papermakers' attention gradually. In this paper, a series of amphoteric starches with different cationic and anionic degree of substitution (DS) are prepared. Better product has been selected and used under different condition. As retention and drainage aids, amphoteric starches were used in shorter fiber length, weak strength and poor drainage bleached AQ-Soda wheat straw pulp. In neutral and alkaline papermaking system, when amphoteric starches contain 0.024-0.026 anionic degree of substitution (DS), it is shown that the higher the cationic degree of substitution (DS) in amphoteric starches, the better the filler retention. The filler retention is improved 12.5%, 30.3%, and 35.1% and 32.5% respectively by adding 1% amphoteric starch LS-L2 -1 (0.034), LS-L2-2 (0.040), LS-L2-3 (0.047) and LS-L2-4 (0.052). But the strength of handsheets if affected a little. By adding 2% Al2 (SO4)3 and 1.5% LS-L2-3 at pH 7.5, filler retention can be improved from 38% to 80%, and breaking length of sheet only decreases 3.2%. As dry strengthening aids, amphoteric starches were used in eucalyptus APMP. Amphoteric starches are used in eucalyptus APMP. The amphoteric starch LS-L2-2 is better dry strength aid. Adding 1% LS-L2-2 can improve breaking length 24.5%, burst index 42.9%, tear index 38.8%, folding endurance and density of the handsheets.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제36회 동계학술대회 초록집
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• pp.105.2-105.2
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• 2009

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.192-192
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• 2010

DAPAS (Development of Advanced Power system by Applied Superconductivity technologies) program that the, superconductivity national program has been started one of the 21C frontier programs from 2001 in Korea. The 3rd phase of DAPAS program was started at April 2007, and the ultimate goal of HTS cable project is to develop 154kV, 1GVA class HTS cable. The structure of 154kV, 1GVA HTS cable is single core with cold dielectric insulation. The cable core consists of the former, conduction layer, electrical insulation layer, shielding layer. The cable cryostat consists of two corrugated seamless aluminum tubes as its high sealing reliability, the tubes separated through a spacer arrangement. Outdoor termination was developed by LS cable and cryogenic system by CVE for 154kV, 1GVA class HTS cable. The 154kV, 1GVA HTS cable will be installed and be tested in KEPCO Gochang Testing Center from June 2010.

• 한국축산식품학회:학술대회논문집
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• 한국축산식품학회 2005년도 정기총회 및 제35차 춘계 학술 발표대회
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• pp.331-337
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• 2005

한우와 홀스타인의 분변으로부터 MRS배지와 LAPT배지를 이용하여 무작위 선발법으로 54균주의 유산균을 1차로 분리 하였다. 1차로 분리된 54균주에 대해 내담즙성이 우수한 10균주를 분리 한 다음 내산성을 조사한 결과 인공위액 pH2.5에서 LS1, LS15 및 LL6 균주가 각각 66.5%, 82.6% 및 80.7%의 생존율을 나타내었다. Sal. typhimurium, Sta. aureus 및 Cl. perfringens 의 병원균에 대해 가장 큰 항균력을 보인 균주는 LL6와 LL7이었다. API CHL kit로 동정한 결과 LS1, LS2 및 LM1 균주는 모두 L. fermentum, LL6와 LL7 균주L. acidophilus, LS3 균주는 L. plantarum으로 각각동정 되고, 나머지 4균주는 Lactobacillus sp. 로 동정되어 분리된 10균주 모두 안전성 있는 유산 간균임을 확인하였다. 10종류의 항생제에 대한 내성을 조사한 결과 ampicillin, amoxicillin and erythromycin 에 대해서는 억제되었으나 colistin과 ciprofloxacin에 대해 모두 내성을 나타내었다. LB1, LL6 및 LL7 균주는 gentamicin과 neomycin에 대해 내성을 보여 주었다. 분리 동정된 균주 중에 내산성, 내담즙성 및 병원성균에 대한 항균력이 우수한 것으로 probiotic 유산균으로 사용가능성이 높은 것은 LL6인 L. acidophilus 로 나타났다.

• 한국축산시설환경학회지
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• 제12권3호
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• pp.107-114
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• 2006

본 연구는 젖소에 있어서 세족기 및 신개발 세족액의 적용효과를 구명하기 위하여 2004년 축산연구소 및 전문경영체농장 2개소에서 사육중인 홀스타인 착유우를 대상으로 신개박 세족기 및 세족액을 적용하여 다음과 같은 결과를 얻었다. 1. 유산동의 MIC와 MBC는 E. coli 및 Bacillus에 대해서 공히 0.31%로 나타났다. 신개발 세족액의 경우 E. coli에 대해서는 MBC가 5%로 나타났고 Bacillus에 대해서는 2.50%로 나타났다. 2. E. coli의 경우 5% 및 16% 농도에서 각각 95.69% 및 95.87%의 감소율을 나타내었고 Bacillus의 경우 5% 및 16% 농도에서 각각 99.5% 및 99.89%의 감소율을 나타내었다. 3. 30일동안 사용하였을 때 보행자세지수(locomotion score ; LS) 2, LS3, LS4 및 LS5의 경우 100%, 43.8%, 14.3% 및 0%의 정상회복율을 나타내었고 누적하여 60일동안 사용하였을 때 LS2, LS3, LS4 및 LS5의 경우 100%, 81.3%, 71.4% 및 50.0%의 정상회복율을 나타내었다. 4. 신개발 세족액을 사용하기 전과 후의 발굽장애 발생율에 있어서 사용 전에는 18.8%의 발생율을 보였으나 사용 후에는 1.5%의 발생율을 나타내었다.