• 한국지역사회생활과학회지
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• 제19권2호
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• pp.297-308
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• 2008

Previous research on elderly care in rural areas has focused on inter-generational support, ignoring the possibility of elderly care among community members in the rural areas of Korea. This study attempts to explore the roles and potentials of community-based elderly care in rural areas where nearby family or formal services are unavailable. For this purpose, data was collected from the elderly in three Korean rural villages using qualitative case study methods. Each village was studied as a separate case study and in-depth interviews with the elderly in each village were conducted. All interviews were tape-recorded and transcribed verbatim for the analysis. The data was analyzed using the Reflective Qualitative Analytic Technique. Results showed that rural elderly in all three villages had lunch, talked, and played together; almost everyday in the winter. However, the nature of care among rural elderly varied depending on the characteristics of the rural community (the traditional rural, the rural mixed with the urban, and the neighboring rural with the urban). Specifically, the use of mutual aids (providing food, repairing housing, and checking personal safety by telephone or visit, etc.) was most consistent at the traditional rural village. Because both the rural village mixed with the urban and the neighboring rural village with urban have better access to many aids and programs from formal institutions, mutual aids among community members decreased compared with the traditional rural village. However, regular group activities such as sports, dancing or debate help to provide pleasure and integrate the community. These results suggest that community relationships as a substitution for social support provide by family or formal services can be utilized in rural areas.

• 한국안전학회지
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• 제28권3호
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• pp.44-50
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• 2013

Process gas piping is one of the most basic components frequently used in the refinery and petrochemical plants. Many kinds of by-product gas have been used as fuel in the process plants. In some plants, natural gas is additionally introduced and mixed with the byproduct gas for upgrading the fuel. In this case, safety or design margin of the changed piping system of the plant should be re-evaluated based on a proper design code such as ASME or API codes since internal pressure, temperature and gas compositions are different from the original plant design conditions. In this study, series of piping stress analysis were conducted for a process piping used for transporting the mixed gas of the by-product gas and the natural gas from a mixing drum to a knock-out drum in a refinery plant. The analysed piping section had been actually installed in a domestic industry and needed safety audit since the design condition was changed. Pipe locations of the maximum system stress and displacement were determined, which can be candidate inspection and safety monitoring points during the upcoming operation period. For studying the effects of outside air temperature to safety the additional stress analysis were conducted for various temperatures in $0{\sim}30^{\circ}C$. Effects of the friction coefficient between the pipe and support were also investigated showing a proper choice if the friction coefficient is important. The maximum system stresses were occurred mainly at elbow, tee and support locations, which shows the thermal load contributes considerably to the system stress rather than the internal pressure or the gravity loads.

• 콘크리트학회논문집
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• 제17권1호
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• pp.105-112
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• 2005

트럭믹서 및 배쳐 플랜트 세척으로 발생되는 회수수를 안정화시켜 재이용하는 것은 콘크리트의 품질 불안정을 해소하고 강도 향상의 효과를 기대할 수 있기 때문에 이의 활용방안에 대한 적극적인 검토가 요구된다. 본 연구에서는 우리나라의 레미콘 생산 조건에서 사용 가능한 안정화제의 종류를 도출하고자 이를 사용한 회수수 중의 고형분 성상에 대하여 실험?고찰하였다. 실험결과, 회수수 전용 안정화제인 옥시칼본산계 지연제의 고형분량 감소가 상대적으로 우세하였다. 다만, 잉여 반응량에 의해 시멘트 페이스트의 응결지연이 관찰되었으나 레미콘 적용상 저해되는 수준은 아니었다. 안정화제를 혼입한 회수수를 방치함에 따른 영향에서는 초기의 응결지연 효과가 7${\~}$8일 정도에서 상수도수만을 사용한 수준으로 회복됨을 알 수 있었으며, 2${\~}$3일 정도에 안정화 회수수를 사용하는 것이 효과적임을 확인할 수 있었다. 한편, 국내산 당류계 초지연제 역시 유사한 효과를 보여 적용성이 높은 것으로 파악되었다. 시판되는 회수수 안정화제는 수입에 의존하고 있으므로 사회비용의 절감을 위해 안정화제의 국산화가 시급하며 가능한 안정화제의 다각적인 사용성 검토가 긴요하다 할 것이다.

• 의학교육논단
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• 제24권3호
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• pp.215-230
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• 2022

The purpose of this study was to explore the psychosocial characteristics of academically maladjusted students and the College's current status regarding academic maladjustment based on 4-year medical student cohort data collected from 2018 to 2021 and through interviews with 10 medical education experts using the integrated research method. This study included 223 students who consented to inclusion in the student cohort and participated in the emotional behavior test and college adaptability test of whom 65 students experienced academic maladjustment. Academically maladjusted students had significantly higher scores for social stress, anxiety, sense of inadequacy, attention, hyperactivity, and school maladjustment, and significantly lower scores for relationships with parents, interpersonal relationships, self-esteem, self-confidence, and self-strength. Academic and social integrity, emotional stability, university satisfaction, and university service satisfaction were all significantly lower in the academically maladjusted students than in the non-maladjusted group. The expert interviews indicated that academic maladjustment was mainly recognized as a personal problem, with causes such as lack of motivation and learning methods, vulnerability to stress, lack of social relationships and alienation, lack of support from the family, and insufficient resilience. Systematic support other than counseling for academically maladjusted students is required, and an early diagnosis and preventive intervention are important.

• 한국지반환경공학회 논문집
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• 제13권12호
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• pp.75-79
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• 2012

생활폐기물과 달리, 산업폐기물의 재활용에 대해서는 위험성이나 유해성 등의 우려와 선입견 때문에 정부차원의 제도적 지원은 물론 법규 등의 정비도 이루어지지 않고 있다. 따라서 산업폐기물의 재활용에 대한 법규와 제도적 정비가 시급한 실정이다. 본 연구에서는 회사장 혼합석탄재에 대한 환경인자들의 검토과정과 결과를 고찰 정리함으로써 산업폐기물인 혼합석탄재를 건설재료로 활용함에 있어 필요로 하는 환경적 검토 방법을 제시하고 있다. 회사장 혼합석탄재는 일반폐기물로 분류되고, 폐기물공정시험 방법에 의한 용출실험 결과의 해당 항목을 비교 검토한 결과 본 연구에서 제안한 '환경적 안전 기준'을 충족하고 있어 건설재료로의 재활용에는 환경적 문제가 없는 것으로 검토되었다. 그리고 자료축적을 위해 재활용이 이루어진 후에는 시간경과에 따른 주변지역 환경영향조사를 실시함이 필요하다고 사료된다.

• Geomechanics and Engineering
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• 제20권5호
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• pp.461-474
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• 2020

Analysing the incompatible deformation and damage evolution around the tunnels in mixed strata is significant for evaluating the tunnel stability, as well as the interaction between the support system and the surrounding rock mass. To investigate this issue, confined compression tests were conducted on upper-soft and lower-hard strata specimens containing a circular hole using a rock testing system, the physical mechanical properties were then investigated. Then, the incompatible deformation and failure modes of the specimens were analysed based on the digital speckle correlation method (DSCM) and Acoustic Emission (AE) data. Finally, numerical simulations were conducted to explore the damage evolution of the mixed strata. The results indicate that at low inclination angles, the deformation and v-shaped notches inside the hole are controlled by the structure plane. Progressive spalling failure occurs at the sidewalls along the structure plane in soft rock. But the transmission of the loading force between the soft rock and hard rock are different in local. At high inclination angles, v-shaped notches are approximately perpendicular to the structure plane, and the soft and hard rock bear common loads. Incompatible deformation between the soft rock and hard rock controls the failure process. At inclination angles of 0°, 30° and 90°, incompatible deformations are closely related to rock damage. At 60°, incompatible deformations and rock damage are discordant due that the soft rock and hard rock alternately bears the major loads during the failure process. The failure trend and modes of the numerical results agree very well with those observed in the experimental results. As the inclination angles increase, the proportion of the shear or tensile damage exhibits a nonlinear increase or decrease, suggesting that the inclination angle of mixed strata may promote shear damage and restrain tensile damage.

• Korean Chemical Engineering Research
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• 제47권1호
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• pp.11-16
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• 2009

단일벽 탄소나노튜브의 표면 위에 동력학적 전위법으로 산화루테늄($RuO_2$)의 석출 및 루테늄-코발트 혼합산화물(Ru-Co mixed oxide)의 공석출에 의해 산화환원 수퍼커페시터용 복합전극을 제조하였다. 루테늄 성분이 13.13 wt%, 코발트 성분이 2.89 wt%가 석출된 Ru-Co 혼합산화물 전극은 낮은 전위 스캔속도($10\;mV\;s^{-1}$)에서는 $RuO_2$ 전극과 유사한 비용량(${\sim}620\;F\;g^{-1}$)을 나타내지만, 높은 스캔속도($500\;mV\;s^{-1}$)에서는 $RuO_2$ 전극보다 큰 비용량을 보인다. 높은 스캔 속도에서 Ru-Co 혼합산화물 전극이 비용량의 증가를 나타내는 것은 Ru 성분을 통한 전기전도성을 Co 성분이 구조적으로 지지해주기 때문이다.

• Journal of the korean society of oceanography
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• 제36권1호
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• pp.19-26
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• 2001

The biological pump is one of the important pumping mechanisms absorbing CO$_2$ from the atmosphere into the ocean and can be quantified by estimating new production. New production in the open ocean mostly depends on the supply of nitrate from the water below the mixed layer. While nitrate is affected by many biological processes, the helium isotope ($^3$He) is inert and has very simple physical properties. Using the $^3$He flux and the relation between $^3$He and NO${_3}\;{^-}$- within the thermocline, the nitrate flux supporting new production was estimated in the southern East Sea. The average ${\delta}^3$He within the mixed layer was -14$%_o$ and -l5.4$%_o$ in the winter and autumn, respectively. Through the year excess $^3$He occurs in the mixed layer except for a slight depletion of -17$%_o$ in summer. The $^3$He flux of 13$%_o$md$^{-1}$ associated with the concentration gradient at the air-sea interface was calculated from the product of the piston velocity and the excess $^3$He. Tritium decay within the mixed layer could support only 2$%_o$md$^{-1}$ of the flux. Thus, the remaining 11$%_o$md^{-1}$ could be attributed to the flux of tritiugenic $^3$He from the water below the mixed layer. Nitrate and $^3$He were positively correlated within the thermocline layer with the slope of 0.21 ${\mu}$mol kg$^{-1}$ $%_o\;^{-1}$. The annual nitrate flux estimated from the upward flux of $^3$He and the NO$_{3}\;{^-}$-$^3$He relation was 0.8${\pm}$0.2 mol(N) m$^{-2}$yr$^{-1}$. This flux corresponds to an annual new production of 64 g(C) m$^{-2}$yr$^{-1}$, which is consistent with that in the north-west Pacific.

• Nuclear Engineering and Technology
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• 제53권11호
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• pp.3612-3624
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• 2021

At present, in the case of pump fast optimization, there is a problem of rapid, accurate and effective prediction of cavitation performance. In "A Cavitation Performance Prediction Method for Pumps PART1-Proposal and Feasibility" [1], a new cavitation performance prediction method is proposed, and the feasibility of this method is demonstrated in combination with experiments of a mixed flow pump. However, whether this method is applicable to vane pumps with different specific speeds and whether the prediction results of this method are accurate is still worthy of further study. Combined with the experimental results, the research evaluates the sensitivity and accuracy at different flow rates. For a certain operating condition, the method has better sensitivity to different flow rates. This is suitable for multi-parameter multi-objective optimization of pump impeller. For the test mixed flow pump, the method is more accurate when the area ratios are 13.718% and 13.826%. The cavitation vortex flow is obtained through high-speed camera, and the correlation between cavitation flow structure and cavitation performance is established to provide more scientific support for cavitation performance prediction. The method is not only suitable for cavitation performance prediction of the mixed flow pump, but also can be expanded to cavitation performance prediction of blade type hydraulic machinery, which will solve the problem of rapid prediction of hydraulic machinery cavitation performance.

• Journal of applied mathematics & informatics
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• 제33권5_6호
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• pp.485-502
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• 2015

A computational method for solving singularly perturbed boundary value problem of differential equation with shift arguments of mixed type is presented. When shift arguments are sufficiently small (o(ε)), most of the existing method in the literature used Taylor's expansion to approximate the shift term. This procedure may lead to a bad approximation when the delay argument is of O(ε). The main idea for this work is to deal with constant shift arguments, which are independent of ε. In the present method, we construct the formally asymptotic solution of the problem using the method of composite expansion. The reduced problem is solved numerically by using operator compact implicit method, and the second problem is solved analytically. Error estimate is derived by using the maximum norm. Numerical examples are provided to support the theoretical results and to show the efficiency of the proposed method.