• Journal of Preventive Medicine and Public Health
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• 제52권6호
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• pp.355-365
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• 2019

Objectives: In rural areas of Korea, where public transportation infrastructure is lacking and alternative systems are poor, the elderly experience inconveniences in using healthcare, although their need is high. This study aimed to analyze the association between the convenience of transportation and unmet healthcare needs among the rural elderly. Methods: The data used were collected in the 2016 Community Health Survey among rural elderly individuals aged 65 or older. Dependent variable was the unmet healthcare needs, explanatory variable was the convenience of transportation. The elderly were divided into 3 groups: with no driver in the household, with a driver, and the elderly individual was the driver (the self-driving group). Covariates were classified into predisposing, enabling, and need factors. They included gender, age, education, income, economic activity, household type, motor ability, subjective health level, number of chronic diseases, anxiety/depression, and pain/discomfort. The data were analyzed using logistic regression and stratification. Results: A significant association was found between the convenience of transportation and unmet healthcare needs. When examined unadjusted odds ratio of the group with a driver in the household, using the group with no driver as a reference, was 0.61 (95% confidence interval [CI], 0.54 to 0.68), while that of the self-driving group was 0.34 (95% CI, 0.30 to 0.38). The odds ratios adjusted for all factors were 0.69 (95% CI, 0.59 to 0.80) and 0.79 (95% CI, 0.67 to 0.91). Conclusions: We confirmed a significant association between inconvenient transportation and unmet healthcare needs among the rural elderly even after adjustment for existing known factors. This implies that policies aimed at improving healthcare accessibility must consider the means of transportation available.

• 대한교통학회:학술대회논문집
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• 대한교통학회 1997년도 제32회 학술발표회
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• pp.35-72
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• 1997

This study was conducted to develop a methodology to predict utility pole accident rates and to evaluate cost-effectiveness for safety improvement for utility pole accidents. The utility pole accident rate prediction model was based on the encroachment rate approach introduced in the Transportation Research Board special Report 214. The utility pole accident rate on a section of highway depends on the roadside encroachment rate and the lateral extent of encroachment. The encroachment rate is influenced by the horizontal and vertical alignment of the highway as well as traffic volume and mean speed. The lateral extent of encroachment is affected by the horizontal and vertical alignment, the mean speed and the roadside slope. An analytical method to generate the probability distribution function for the lateral extent of encroachment was developed for six kinds of encroachment types by the horizontal alignment and encroachment direction. The encroachment rate was calibrated with the information on highway and roadside conditions and the utility pole accident records collected on the sections of 55mph speed limit of the State Trunk Highway 12 in Wisconsin. The encroachment rate on tangent segment was calibrated as a function of traffic volume with the actual average utility pole accident rates by traffic volume strategies. The adjustment factors for horizontal and vertical alignment were when derived by comparing the actual average utility pole accident rates to the estimations from the model calibrated for tangent and level sections. A computerized benefit-cost analysis procedure was then developed as a means of evaluating alternative countermeasures. The program calculates the benefit-cost ratio and the percent of reduction of utility pole accidents resulting from the implementation of a safety improvement. This program can be used to develop safety improvement alternatives for utility pole accidents when a predetermined performance level is specified.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제10권8호
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• pp.331-338
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• 2021

메타버스(Metaverse)는 초월과 세계를 의미하는 'meta'와 'universe'의 합성어로서 일상생활과 경제 활동이 가능한 디지털 세계이다. 코로나19 대유행을 기점으로 여가 생활을 즐기는 대안 공간으로서 메타버스가 활발히 이용되고 있는 반면에 메타버스 관련 국내 연구는 매우 미미한 실정이다. 이에 국내외 메타버스 선행 연구를 바탕으로 문화 여가 중심의 메타버스 유형 분석과 핵심 특성 도출 연구를 수행하였다. 현재 메타버스 시대가 개화 중인 상황을 고려하여 메타버스 유형별 개발 동향과 관련 기술도 함께 살펴보았다. 아울러 문화 여가 중심의 메타버스 발전 방향을 분야별로 제시하였다. 본 연구는 메타버스의 용도와 목적에 따라 사회, 협업, 여가 등 이론적 모델을 발굴하여 분석한 후 사례 연구를 통해 문화 여가 중심의 메타버스 개념을 확립하고 3가지 유형과 각 특징을 도출함으로써 기존 국내외 연구와 차별화를 두었다. 최신 IT 기술 발전과 생활상의 변화를 반영한 메타버스 개발 연구에 방향성을 제시한다는 것에 의의가 있다.

• 상하수도학회지
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• 제35권2호
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• pp.113-120
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• 2021

High voltage impulse (HVI) has been gained attention as an alternative technique that could control the CaCO₃ scale problems encountered in water main, pipe, cooling tower and heat exchanger vessels. The aim of this study was to investigate the effect of electric field (E) and contact time (t) of HVI on reduction of Ca²⁺ concentration at two different temperatures of 25℃ and 60℃. A kinetic model on the effect of E and t was investigated too. As the E and t increased, the Ca²⁺ concentration decreased more than that of the control (= no HVI). The Ca²⁺ concentration decreased up to 81% at 15 kV/cm at 60℃, which was nearly 2 times greater than the control. With these experimental data-set of reduction of Ca²⁺ concentration under different E and t, the kinetic model was developed. The relationship between E and t required to reduce the concentration of Ca²⁺ by 30% was modeled at each temperature. The empirical model equations were; E^0.83· t = 60.3 at 25℃ and E^0.08· t = 1.1 at 60℃. These equations state the products of Eⁿ and t is always constant, which means that the required contact time can be reduced in accordance with the increment of E and vice versa.

• 대한물리의학회지
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• 제14권3호
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• pp.81-89
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• 2019

PURPOSE: To solve the problems of chronic obstructive pulmonary disease (COPD) patients complaining of muscle fatigue and having limited motor abilities, this study provided the clinical basic data for pulmonary rehabilitation by examining the effects of High Low-Frequency Neuromuscular Electrical Stimulation (NMES) on the respiratory muscle strength, quadriceps muscle activity, and life quality. METHODS: Samples were collected from 20 COPD patients and placed randomly in a low-frequency group (n=10) and high-frequency group (n=10). For a pretest, the respiratory muscle strength (MIP, MEP), quadriceps muscle activity (LF, VM, VL), and life quality (SGRQ) were measured. After applying NMES to each group for 30 minutes at a time, five times a week, for four weeks, a posttest was conducted in the same way as the pretest. RESULTS: Both groups showed significant differences in the respiratory muscle strength, quadriceps muscle activity, and quality of life within the groups and there were significant differences in the quadriceps muscle activity between the groups. CONCLUSION: The four-weeks NMES positively influenced the respiratory muscle strength and life quality by enhancing the function of the quadriceps and exercise tolerance. In particular, high-frequency(75 Hz) NMES was more effective than low-frequency (15 Hz) NMES. This result can be an alternative means to improve the physical functions of COPD patients clinically in the future.

• 한국기후변화학회지
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• 제8권3호
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• pp.213-220
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• 2017

The purpose of this study is to analyze effects of Greenhouse Gas (GHG) emission reduction in district energy business mainly based on Combined Heat and Power (CHP) plants. Firstly this paper compares the actual carbon intensity of power production between conventional power plants and district energy plants. To allocate the GHG from CHP plants, two of different methods which were Alternative Generation Method and Power Bonus Method, have been investigated. The carbon intensity of power production in district energy plants ($0.43tonCO_2e/MWh$) was relatively lower than conventional gas-fired power plants ($0.52tonCO_2e/MWh$). Secondly we assessed the cost effectiveness of reduction by district energy sector compared to the other means using TIMES model method. We find that GHG marginal abatement cost of 'expand CHP' scenario (-$134/ton$CO_2$) is even below than renewable energy scenario such as photovoltaic power generation ($87/ton$CO_2$). Finally the GHG emission reduction potential was reviewed on the projected GHG emission emitted when the same amount of energy produced in combination of conventional power plants and individual boilers as substitution of district energy. It showed there were 10.1~41.8% of GHG emission reduction potential in district energy compared to the combination of conventional power plants and individual boilers.

• 디지털융복합연구
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• 제16권12호
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• pp.41-50
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• 2018

최근 우리나라의 사회영역에서는 주류 경제에 대한 대안으로 사회적 경제라는 개념이 두각을 나타내고 있다. 주목할 부분은 사회적 경제가 시민사회의 실천 영역이라는 본성을 지니고 있음에도 불구하고, 정부가 일자리 창출이라는 가시적 성과를 얻는 수단으로 적극 지원육성하려는 의지를 지니고 있다는 것이다. 이처럼 우리나라에서 사회적 경제는 정부 주도로 육성되고 있으며, 사회적 약자 및 취약계층 일자리 제공이라는 매우 한정된 정책목표 속에서 이해되고 있다. 그러나 사회적 경제 조직들의 정책적 위상이 높아지는 동시에 정부의 재원에 의존하는 비중이 커지면서, 사회적 경제가 지향하는 사회적 가치와 공동체적 함의도 사라지는 문제점이 대두되고 있다. 본 논문은 이러한 상황에 대한 문제의식을 견지하면서 사회적 경제에 대한 담론을 재구성할 것을 제안한다.

• 대한토목학회논문집
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• 제39권1호
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• pp.123-134
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• 2019

본 연구에서는 비조밀 플랜지 단면이 적용된 일축대칭 스텝보의 비탄성 횡-비틀림 좌굴에 대한 새로운 설계식을 제안하였다. 범용유한요소해석 프로그램인 ABAQUS와 회귀분석프로그램인 MINITAB을 사용하여 설계식을 도출하였다. 실험 및 해석에 적용된 매개변수는 플랜지 보강의 길이변수(${\alpha}$), 폭변수(${\beta}$), 두께변수(${\gamma}$)와 비지지길이 비($L_b/h$)가 고려되었으며, 경계조건은 스텝보의 양단을 횡지지하고 힌지/롤러 경계조건 즉 단순보 경계조건을 적용하였다. 제안식 및 해석결과와 비교하기 위한 실험의 경우, 실험체 지간 중앙에서 같은 거리에 있는 2점 하중을 상부플랜지에 가력하여 거동특성을 분석하였다. 본 논문에서 제안된 설계식은 실험결과와 유한요소해석결과의 비교분석을 통하여 합리적인 설계식임을 확인할 수 있었으며, 비조밀플랜지단면이 적용된 일축대칭 스텝보의 횡비틀림좌굴을 계산하는 데 신뢰성 있는 안전한 값을 나타내고 있다.

• 한국ITS학회 논문지
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• 제18권5호
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• pp.171-182
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• 2019

자전거는 무공해 교통수단으로서 레저용 외에도 친환경 대체 교통수단으로 사용량이 증가하고 있다. 이에 따라 자전거에 따른 사고 또한 증가하는 추세이다. 본 연구는 자전거 사고발생시 사고 상황을 파악할 수 있도록 자전거 블랙박스 기술을 구현하는 것을 목적으로 한다. 현재 자전거 블랙박스 제품들은 주로 영상카메라에 의한 것으로 고해상도 카메라를 중심으로 여러 가지 기능을 추가하여 시판되고 있으며 고가로 판매되고 있다. 자전거 사고가 발생하면 사고 당시의 사고 위치와 사고 당시 자전거 상태에 대한 정량적인 데이터가 필요하다. 본 연구에서는 GPS(Global Positioning System: 위성항법장치)에 의하여 시간, 좌표 데이터를 확보하고, IMU(Inertial Measuring Unit : 관성측정장치)센서를 통해 사고 당시의 자전거 가속도와 기울기의 정량적인 데이터를 취득하여, 이를 블랙박스 내부의 메모리 카드에 저장하며, 동시에 블루투스를 이용하여 자전거 운전자의 스마트 폰으로 실시간 전송하여 사고예방 및 운전 상태를 감시하도록 하였다.

• 대한안전경영과학회지
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• 제21권1호
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• pp.1-7
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• 2019

Along with industrial development, various architectural structures have become bigger and higher, leading to an expansion in the size and capacity of construction equipment. And with the development of public transportation, the use of subways as a means of transportation in the city center is increasing, so that vibrations and structural noises are emerging as a new environmental issue. Considering that architectural structures may be used from several decades to hundreds of years after the time of construction, they can be seen as semi-permanent. Due to changes in the vibration-proof polyurethane mats installed in the foundation of these structures, settling may occur and vibration reduction may become inadequate. Therefore, in view of service life, it is necessary to have a high-level standard of reliability and stability. In accordance with this, the Floating Floor System, which uses soft polyurethane foam and can be constructed within a relatively short period of time, has excellent vibration resistant characteristics. It is presented as a great alternative solution to the issue of vibrations caused by subways, railways and building structures. At present, vibration-proof polyurethane mats have been developed up to the same product level as in other advanced countries. However, in the construction of structure foundations, the physical properties of this product and its shape incur changes. If they are installed as such in the structure of a building, it may cause significant impact on stability, requiring that this cause be urgently identified and improved.