• 제목/요약/키워드: Comparison of reducing characteristics

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현장측정을 통한 분기기시스템 주변의 진동특성 평가 (Evaluation of Vibration Characteristics around the Conventional, Turnout System through the Field Measurements)

  • 김영하;엄기영;신민호;박용걸
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2008년도 추계학술대회 논문집
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    • pp.1000-1005
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    • 2008
  • A turnout system which permits trains to pass from one track to another is a combination of the switch, the crossing, lead rails which are necessary to connect the switch and the crossing, two guard rails and switch machines for operating the switch. A turnout is the sole moving part among the railway components and has complex configuration, so the safety has always been raised an issue. In Korea, it is planned to adopt the high speed tilting train, which operates at the maximum speed of 180km/h, at conventional lines. However, for the application of the tilting train to conventional lines, it is prerequisite to establish a stable turnout system allowing the tilting train to pass through it without reducing speed. Therefor, the improved turnout system for the speed-up of conventional lines has been developed and the prototype of the turnout system has been constructed. In this study, evaluation of Vibration characteristics around the improved turnout system was performed through the field measurements. Field measurements of Vibration around the conventional and the high-speed turnout system were also carried out for the comparison.

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장기요양노인 가족수발자의 부양 실태에 관한 연구: 배우자 수발자와 자녀 수발자의 비교를 중심으로 (Family Caregivers of the Impaired Elderly: A Comparison between Spouses and Adult Children)

  • 신꽃시계;한경혜
    • 한국지역사회생활과학회지
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    • 제22권1호
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    • pp.35-51
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    • 2011
  • This study examined how caregiving experiences of spouses and adult children were different to each other in terms of caregiver characteristics, the impairment level of the elderly, caregiving time, caregiver burden, the effects of long-term care services, etc. Data were collected from 321 spouses and 324 adult children who cared for the functionally and/or cognitively impaired elderly using long-term care services. The main results are as follows. (1) Caregiver characteristics differed significantly between spouses and adult children. (2) Adult children cared for the more severely impaired elderly in terms of IADL, cognitive impairment, and behavior problems while spouses spent more time helping in ADL activities. (3) Spouse caregivers experienced greater overall burden, worry and strain, and financial burden compared to adult child caregivers. (4) Long-term care services were effective in reducing caregiver burden and improving family relations. Additionally, relations between adult child caregivers and the elderly was more improved than relations between spouse caregivers and the elderly after using long-term care services. Based on these findings, the differential experiences between spouse caregivers and adult child caregivers were discussed.

Dosimetric comparison between modulated arc therapy and static intensity modulated radiotherapy in thoracic esophageal cancer: a single institutional experience

  • Choi, Kyu Hye;Kim, Jina;Lee, Sea-Won;Kang, Young-nam;Jang, HongSeok
    • Radiation Oncology Journal
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    • 제36권1호
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    • pp.63-70
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    • 2018
  • Purpose: The objective of this study was to compare dosimetric characteristics of three-dimensional conformal radiotherapy (3D-CRT) and two types of intensity-modulated radiotherapy (IMRT) which are step-and-shoot intensity modulated radiotherapy (s-IMRT) and modulated arc therapy (mARC) for thoracic esophageal cancer and analyze whether IMRT could reduce organ-at-risk (OAR) dose. Materials and Methods: We performed 3D-CRT, s-IMRT, and mARC planning for ten patients with thoracic esophageal cancer. The dose-volume histogram for each plan was extracted and the mean dose and clinically significant parameters were analyzed. Results: Analysis of target coverage showed that the conformity index (CI) and conformation number (CN) in mARC were superior to the other two plans (CI, p = 0.050; CN, p = 0.042). For the comparison of OAR, lung V5 was lowest in s-IMRT, followed by 3D-CRT, and mARC (p = 0.033). s-IMRT and mARC had lower values than 3D-CRT for heart $V_{30}$ (p = 0.039), $V_{40}$ (p = 0.040), and $V_{50}$ (p = 0.032). Conclusion: Effective conservation of the lung and heart in thoracic esophageal cancer could be expected when using s-IMRT. The mARC was lower in lung $V_{10}$, $V_{20}$, and $V_{30}$ than in 3D-CRT, but could not be proven superior in lung $V_5$. In conclusion, low-dose exposure to the lung and heart were expected to be lower in s-IMRT, reducing complications such as radiation pneumonitis or heart-related toxicities.

산지별 고아라 마늘의 주요 성분과 항균활성 비교 (Comparison of the major compounds and antimicrobial activities of Koara garlic cultivated in different regions)

  • 김주성;라종환
    • 한국식품과학회지
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    • 제51권3호
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    • pp.258-262
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    • 2019
  • 마늘의 일부 품종에서 화학적 조성 및 생물학적 특성이 조사되었지만 현재 고아라 마늘의 주요 성분 및 생리활성에 대한 조사는 부족한 현실이다. 2012년 품종으로 등록된 고아라 마늘의 주요성분 및 생리활성을 측정하기 위하여 서귀포, 담양 및 남해에서 재배하여 비교하였다. 재배된 마늘 성분을 분석한 결과 서귀포에서는 황 관련 물질(알리인과 피루베이트 총량)과 항균 활성이 우수했으며 남해에서는 페놀 함량과 환원당 함량이 풍부하였으며, 담양에서는 총 플라보노이드 함량이 높게 나타났다. 위의 결과를 고려할 때 재배 지역 간에는 차이가 있었지만 고아라 마늘은 지금까지 보고된 다른 마늘 품종과 비슷하게 주요 성분함량과 생리 활성을 보여주었다. 이러한 연구 결과는 지역 농민, 유통 업자 및 소비자에게 유용한 정보가 될 것이다.

고 투과 효율과 소형 빔 스팟 면적을 갖는 근접장 마이크로웨이브 도파관 탐침의 설계 (Design of the Near Field Microwave Guide Type of Probe Having Enhanced High Transmission Efficiency and Smaller Beam Spot Area)

  • 고지환;조영기
    • 한국전자파학회논문지
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    • 제26권12호
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    • pp.1058-1063
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    • 2015
  • 본 연구에서는 높은 투과 효율은 유지하면서 스팟 면적을 보다 획기적으로 줄일 수 있도록 가느다란 두 개의 짧은 도체 봉이 리지(H-형태) 개구의 중심에 부착된 근접장 마이크로웨이브 주사 탐침 구조를 제안하였다. 여기서 두 개의 짧은 도체 봉은 H-형태 개구를 통과하는 투과 전자파 에너지를 집속하게 하여, 고 해상도를 위해 스팟 면적을 극히 작게 줄어들게 하는데 중요한 역할을 한다. 제안된 이론의 타당성을 확인하기 위해 모의실험 결과에 따라 근접장 도파관 탐침을 제작하고, 반사손실을 측정하여 계산결과와 비교적 일치된 결과를 얻었다.

미국 도입 수수 유전자원의 항산화활성과 항균활성 (Antioxidant and Antimicrobial Activities of Sorghum Germplasms Introduced from USA)

  • 고은정;유지혜;성은수;이재근;황인성;김남준;유창연
    • 한국자원식물학회지
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    • 제25권2호
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    • pp.193-199
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    • 2012
  • 본 연구는 미국 수수 수집종의 작물학적 특성 및 생리활성을 검정하기 위하여 수행되었다. 대부분의 미국 수수 수집종은 200 cm 이상의 큰 초장을 보였으며, 간경 또한 2cm 이상의 값을 나타냈다. 수수 수집종 중에서는 Sweet-N-Sterile(#4)이 가장 우량한 수수의 생장 특성을 보였다. 수수의 DPPH를 이용한 활성 검정 결과, Premium stock(#1), Early Sumac(#7), SS Silage(#9), WGF Grain Sorghum(#11) 4개의 수집종에서 기존의 항산화제인 ${\alpha}$-tocopherol과 BHA와 비슷한 활성을 보였고 BHT보다는 높은 활성을 보였다. 항미생물 실험결과 BMR Gold I(#3)이 가장 높은 활성을 나타냈으며, 특히 $Escherichia$ $coli$에서 125 ${\mu}g$/ml으로 높은 활성수치를 나타냈다.

Overview of the Development of the Korean Exposure Factors Handbook

  • Jang, Jae-Yeon;Jo, Soo-Nam;Kim, So-Yeon;Myung, Hyung-Nam
    • Journal of Preventive Medicine and Public Health
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    • 제47권1호
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    • pp.1-6
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    • 2014
  • A set of exposure factors that reflects the characteristics of individual behavior capable of influencing exposure is essential for risk and exposure assessment. In 2007, the Korean Exposure Factors Handbook was, therefore, issued, driven by the need to develop reliable exposure factors representing the Korean population. The purpose of this study was to overview the development process of the Korean Exposure Factors Handbook and major recommended exposure values for the Korean population to allow information exchanges and comparison of recommended values among nations. The researchers reviewed the domestic data that could be used in the development of exposure factors, confirmed a knowledge gap, and set a priority of development by phases. A methodology to measure exposure factors was established to develop measuring techniques and test their validity. Data were processed or a survey was conducted according to the availability of data. The study thus produced recommended values for 24 exposure factors grouped by general exposure factors, food ingestion factors, and activity factors by setting up a database of exposure factors and carrying out statistical analysis. The study has significantly contributed to reducing the potential uncertainty of the risk and exposure assessment derived by the application of foreign data or research findings lacking representativeness or grounds by developing a set of exposure factors reflecting the characteristics of the Korean people. It will be necessary to conduct revisions in light of the changing statistical values of national data and the exposure factors based on Korean characteristics.

기능적 전기자극기를 이용한 간헐적 고주파 교대자극과 간헐적 저주파 동시자극의 근 수축력 비교 (A Comparison of Muscle Contraction Using Functional Electrical Stimulation: Intermittent High Frequency Alternating Stimulation Versus Intermittent Low Frequency Synchronous Stimulation)

  • 송영희;조상현;이영희
    • 한국전문물리치료학회지
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    • 제9권2호
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    • pp.115-131
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    • 2002
  • Functional electrical stimulation (FES) training of the knee extensors is a useful way to rehabilitate the ability to stand and walk. However, training using FES has not been able to solve the problem of fatigue; clinical application of FES quickly produces muscle fatigue, due to the continuous activation of the muscles of the lower extremity. Therefore, reduction of muscle fatigue is an important factor in increasing the effectiveness of FES training in paraplegia. Intermittent high frequency alternating stimulation is a method that combines the advantages of high frequency (leading to strong muscle contractions) and alternating stimulation (reducing muscle fatigue), thereby continuously strengthening muscles. It is not known whether low frequency simultaneous stimulation results in stronger muscle contraction than high frequency alternating stimulation. This study compared the effectiveness of high frequency alternating stimulation with low frequency synchronized stimulation. Muscle power using FES on the quadriceps of 20 normal subjects were compared. Intermittent high frequency alternating stimulation did not produce more powerful muscle contraction than intermittent low frequency synchronized stimulation, because the muscle characteristics differed individually. Significant individual variation according to muscle characteristics was founded when applying FES. Accordingly, when physical therapists use FES to treat patients, they must be aware of individual variation in muscle characteristics.

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떫은감 분말을 첨가한 설기떡의 품질특성 (Quality Characteristics of Sulgidduck prepared by Addition of Astringent Persimmon Powder)

  • 김귀영;문혜경;이수원
    • 한국식품저장유통학회지
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    • 제13권6호
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    • pp.697-702
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    • 2006
  • 떫은 감 분말의 첨가량 (0, 5, 10, 15, 20%)을 달리하여 설기떡의 품질 특성을 조사하였다. 감설기의 수분함량은 감 분말 첨가군 무 처리구에 비해 낮게 나타났으며, 환원당, 유리당(fructose, glucose, sucrose), 무기질(Ca, K, Mg) 함량은 떫은 감 분말 함량이 증가할수록, 함량이 증가하는 경향을 보였다. 색도는 떫은 감분말의 첨가량이 증가할수록 L값은 낮아지고, a값과 b값이 증가하였고, texture 측정에서 adhesiveness, cohesiveness, gumminess, chewiness 값은 낮아지는 경향을 나타내었다. 관능검사 결과 떫은 감분말의 첨가가 무 처리구에 비해 전반적인 기호도가 높은 간을 나타났고, 15% 첨가구가 가장 높은 값을 나타내었다. 이상의 결과로 설기떡 제조시 첨가하는 설탕시럽 대용으로 여러가지 기능성물질과 단맛을 함유하고 있는 떫은 감을 식품의 소재로 이용될 수 있는 충분한 가치가 있다고 사료된다.

다단연소를 이용한 저 NOx 버너의 연소특성에 관한 연구 (An Experimental Study on the Combustion Characteristics in Low Emission Multi-Staged Oil Burner)

  • 안국영;김한석;조은성
    • 연구논문집
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    • 통권27호
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    • pp.101-108
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    • 1997
  • The characteristics of combustion and emissions in multi-staged oil burner have been experimentally studied for the various range of equivalence ratios, drop sizes and fuel formulations. Malvern system was used to measure droplet size of fuel. Light fuel oil and light fuel oil doped with pyridine($C_5H _5N$) were used to investigate the effects on fuel NOx emission. The emissions of NO and CO in exhaust gas and the flame temperatures were measured by the gas analyzer and thennocouples. NOx emissions were increased by increasing the excess air ratio (range:$lambda=1.1-1.4$) or decreasing the SMD of droplet in single-staged burner. In comparison with the single-staged burner, the emission of NOx in multi-staged burner was reduced by 50% but CO emission was slightly increased. It is found that multi-staged burner has a good capability in reducing thermal NOx resulting from the distributed heat release rate and lower flame temperature in fuel-rich and fuel-lean combustion zone. Moreover, the fuel NOx emission of the multi-staged burner is lower than that of single-staged burner, because multi-staged burner has fuel rich zone where fuel N is converted to $N_2$ more than NO. In 3-staged burner, the percentage of each stage combustion air have strong influence on emission characteristics. It is also found that NOx emission can be reduced by decreasing inner and outer air percentage or increasing middle air flow rate and CO emission is vice versa.

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