• 한국환경보건학회지
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• 제49권6호
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• pp.362-371
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• 2023

Background: PM_2.5 pollution has been a persistent problem in South Korea, with concentrations consistently exceeding World Health Organization (WHO) guidelines. The aging of the population in the country further exacerbates the health impacts of PM_2.5 since older adults are more susceptible to the adverse effects of air pollution. Objectives: This study aims to evaluate how the health impact (premature death) due to long-term exposure to PM_2.5 in South Korea could change in the future according to the trend of change in the country's population structure. Methods: The study employs a relative risk function, which accounts for age-specific relative risks, to assess the changes in premature deaths by age and region at the average annual PM_2.5 concentration for 2022 and at PM_2.5 concentration improvement levels. Premature deaths were estimated using the Global Exposure Mortality Model (GEMM). Results: The findings indicate that the increase in premature deaths resulting from the projected population structure changes up to 2050 would significantly outweigh the health benefits (reduction in premature deaths) compared to 2012. This is primarily attributed to the rising number of premature deaths among the elderly due to population aging. Furthermore, the study suggests that the effectiveness of the current domestic PM_2.5 standard would be halved by 2050 due to the increasing impact of population aging on PM_2.5-related mortality. Conclusions: The study highlights the importance of considering trends in population structure when evaluating the health benefits of air pollution reduction measures. By comparing and evaluating the health benefits in reflection of changes in population structure to the predicted PM_2.5 concentration improvements at the provincial level, a more comprehensive assessment of regional air quality management strategies can be achieved.

• Computers and Concrete
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• 제33권5호
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• pp.605-619
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• 2024

The increase of reclaimed asphalt pavement (RAP) content in recycled asphalt concrete (RAC) is accompanied by the degradation of low-temperature cracking resistance, which has become an obstacle to the development of RAC. This paper aims to reveal the meso-scale mechanisms of the low-temperature fracture behavior of RAC and provide a theoretical basis for the economical recycling of RAP. For this purpose, micromechanical heterogeneous peridynamic model of RAC was established and validated by comparing three-point bending (TPB) test results against corresponding numerical simulation results of RAC with 50% RAP content. Furthermore, the models with different aggregate shapes (i.e., average aggregates circularity (${\bar{C_r}}=1.00$, 0.75, and 0.50) and RAP content (i.e., 0%, 15%, 30%, 50%, 75%, and 100%) were constructed to investigate the effect of aggregate shape and RAP content on the low-temperature cracking resistance. The results show that peridynamic models can accurately simulate the low-temperature fracture behavior of RAC, with only 2.9% and 13.9% differences from the TPB test in flexural strength and failure strain, respectively. On the meso-scale, the damage in the RAC is mainly controlled by horizontal tensile stress and the stress concentration appears in the interface transition zone (ITZ). Aggregate shape has a significant effect on the low-temperature fracture resistance, i.e., higher aggregate circularity leads to better low-temperature performance. The large number of microcracks generated during the damage evolution process for the peridynamic model with circular aggregates contributes to slowing down the fracture, whereas the severe stress concentration at the corners leads to the fracture of the aggregates with low circularity under lower stress levels. The effect of RAP content below 30% or above 50% is not significant, but a substantial reduction (16.9% in flexural strength and 16.4% in failure strain) is observed between the RAP content of 30% and 50%. This reduction is mainly attributed to the fact that the damage in the ITZ region transfers significantly to the aggregates, especially the RAP aggregates, when the RAP content ranges from 30% to 50%.

• 토지주택연구
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• 제15권2호
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• pp.73-87
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• 2024

통근 패턴의 효율성을 평가하기 위해 초과 통근율과 통근 잠재력 사용률과 같은 다양한 통근 지표들이 개발되고 사용되어 왔다. 이들 지표들을 활용하여 대도시권의 통근 패턴 차이를 밝히고, 이를 통근 정책 수립 과정에서 고려할 수 있기에 지표를 합리적으로 산출하는 것은 매우 중요하다. 그런데, 통근 지표는 일반적으로 행정구역 단위로 산출되기 때문에 공간단위 수정가능성의 문제(MAUP)로부터 자유롭지 못하다는 한계가 있다. 이 문제는 대도시권 간 통근 효율성 비교의 합리성을 저해하기 때문에 통근 지표 산출 과정에서 조심스럽게 다뤄져야 할 필요가 있다. 따라서, 본 연구는 몬테 카를로 시뮬레이션을 활용하여 최적, 실제, 그리고 최대 통근 거리를 산출하고, 이를 통해 초과 통근율과 통근 잠재력 사용률을 제시한다. 몬테 카를로 시뮬레이션을 우리나라의 사정에 맞게 적용하기 위해서, 시뮬레이션에 사용되는 주거지와 근무지가 실제 건물의 위치에서 선택되어야 한다는 제약 조건을 가한 제약조건부 몬테카를로 시뮬레이션을 실시한다. 2016년 가구통행실태조사 데이터를 이용하여 광역도시계획이 수립된 13개 대도시권을 대상으로 분석을 진행한다. 시뮬레이션을 통해 산출된 통근 지표는 기존 방법을 통해 산출된 결과와 미미한 수준의 차이를 보였다. 대도시권 간 통근 효율성 비교 결과 직주의 물리적 균형의 정도가 유사하더라도 실제 통근 패턴은 상이하게 나타난다는 점이 확인되었다. 향후 면적과 같은 대도시권별 특성을 고려한 추가적인 연구가 필요할 것으로 생각된다.

• 한국환경복원기술학회지
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• 제27권3호
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• pp.1-18
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• 2024

The study aims to establish a direction for forest ecological restoration by classifying forest types and understanding the ecological characteristics of the Uljin forest area damaged by a large fire in 2022. Hierarchical cluster analysis and indicator species analysis were conducted on 78 survey plots located in the forest fire-affected area, and four forest cover types were derived: P. densiflora pure forests, P. densiflora dominant forests, mixed broad-leaved forests, and Q. variabilis dominant forests. As a result of visually comparing changes in forest types before and after forest fire damage, by classifying data according to whether or not upper dead trees are included, it was confirmed that pine forests, which have a high proportion of pine trees, spread widely due to forest fire damage. However, broad-leaved mixed forests and oyster oak dominant forests showed characteristics of maintaining concentration, indicating that pine forests were severely damaged. As a result of the important value analysis, during the process of natural recovery after a forest fire, the species that appear early in the lower layer are the sprouts of existing species such as Quercus mongolica Fisch. ex Ledeb., Quercus variabilis Blume, Fraxinus sieboldiana Blume, Rhododendron mucronulatum Turcz. The distribution of diameter at breast height by forest cover type showed that among areas with extreme forest fire damage, the proportion of dead trees was relatively high and structural changes were large in P. densiflora pure forests and P. densiflora dominant forests where pine trees had a high distribution ratio. However, if continuous monitoring is carried out in the future with reference to the results of this study and plant data is collected and analyzed from a mid- to long-term perspective, it is believed that it will be used as useful data to promote forest ecological restoration projects in forest fire-affected areas.

• 방사선산업학회지
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• 제17권1호
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• pp.33-44
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• 2023

The deep geological repository of high-level radioactive waste shall be designed to meet the safety objective set in the form of radiation dose or corresponding risk to protect human and the environment from radiation exposure. Engineering feasibility and conformity with the safety objective of the facility conceptual design can be demonstrated by comparing the assessment result using the computational model for scenario(s) describing the radionuclide release and transport from repository to biosphere system. In this study, as the preliminary study for developing the high-level radioactive waste disposal facility in Korea, we reviewed and analyzed the entire list of FEPs and how to handle each FEP from a general point of view, which are selected for the geosphere region in the radiological safety assessment performed for the license application of the KBS-3 type deep geological repository in Finland and Sweden. In Finland, five FEPs (i.e., stress redistribution, creep, stress redistribution, erosion and sedimentation in fractures, methane hydrate formation, and salt exclusion) were excluded or ignored in the radionuclide release and transport assessment. And, in Sweden, six FEPs (i.e., creep, surface weathering and erosion, erosion/sedimentation in fractures, methane hydrate formation, radiation effects (rock and grout), and earth current) were not considered for all time frames and earthquake out of a total of 25 FEPs for the geosphere. Based on these results, an FEP list (draft) for the geosphere was derived, and the relative importance of each item was evaluated for conducting the radiological safety assessment of the domestic deep geological disposal facility. Since most of information on the disposal facility in Korea has not been determined as of now, it is judged that all FEP items presented in Table 3 should be considered for the radiological safety assessment, and the relative importance derived from this study can be used in determining whether to apply each item in the future.

• Journal of Acupuncture Research
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• 제17권1호
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• pp.27-41
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• 2000

The meridian system is the most essential and basic connecting structure that maintains the vital activities of viscera and bowels by connecting them with each part of body's surface. Doctors can understand the healthy condition, and the region and deficiency-excessiveness of disease by observing the condition of Qi flowing. Deficiency and excessiveness could be differentiated by various symptoms expressed in meridian system. Especially there could be several clues like pain, heat-cold, protuberance-depression, change of color and shine in the line of channel leads to the judgment of deficiency-excessiveness The diagnosis of deficiency and excessiveness can be generalized by quantification of elastic status in skin surface along the meridian system. By comparing data from measurement of elastic condition with those from traditional deficiency and excessiveness, it could be utilized for the development of oriental medicine. All biological activities in the human body are based on meridian system according to the oriental medicine. Also the meridian system is viewed as basic and essential structure connecting internal viscera and each part of body. The areas of expressed channel phenomena are muscle to bone, muscle to muscle and bone to bone. These areas are called depression where meridian system is present and any changing state on those points can be measured. It could be difficult in diagnosing the reaction of meridian system because doctor can depend on his own judgment. Therefore, it is necessary to quantify and indexate channel reactions. To quantify the channel reactions, specially manufactured instrument was used to quantify the protuberance and depression to differentiate the deficiency and excessiveness. The results follow as below; 1. The elastic index measurement by the equipment proved a pattern of agreement showing the values that ranged within standard deviation 0.05kgf/cm throughout the experiment except few cases' measurement in CV-17. 2. To evaluate the state of deficiency & excessiveness of elastic index measurements in frontal point, elastic index measurements in the front paint were compared to the elastic index measured surrounding the point within 2.5 cm. Such result of indexing procedure was closely matched to the concept of palpitation. 3. If the elastic index values in the surrounding front point closely located to the elastic index values in the front point, the judgement on the state of deficiency and excessiveness was delayed. Otherwise, it was judged as deficiency or excessiveness. 4. Out of total 12 cases of comparing the elastic index values to the elastic index values in the surrounding front point, Three to nine front points were judged as either in the state of deficiency or excessiveness. 5. Among the nine front points judged as either in the state of deficiency or excessiveness, Four cases were matched to the electric index measured by EAV that evaluating the internal organs by five different phases. If more clinical cases are accumulated, it is expected to systematically theorize and improve the concept of deficiency and excessiveness in the internal organs using the front point.

• 치위생과학회지
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• 제11권3호
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• pp.229-234
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• 2011

본 연구는 2009 국민건강영양조사자료를 근거로 6세 이상 인구의 DMFT index(9,271명)를 구하고 그 중 상위 1/3인 고위험군을 분류하여 SiC index(2,517명)를 산출하였다. 이에 치아우식증 고위험군의 존재를 확인하고 고위험군에 대한 예방전략의 필요성을 강조하고자 하였다. 통계 분석은 STATA 11.0 프로그램을 이용하여 t-test 분석을 하였다. 1. DMFT index의 연구대상자는 남자가 45.0%(4,174명), 여자가 55.0%(5,097명)이었으며, SiC index 대상자를 산출한 결과 전체 2,517명이었으며, 남자는 36.3%(914명), 여자는 63.7%(1,603명)로 SiC index에서 여자가 더 많았다. 2. DMFT index와 SiC index의 평균을 보면 연령이 증가할수록 두 집단 간 평균의 차이가 컸으며, 특히 13, 14세는 평균 4 이상, 15세 이상부터는 평균 2배 이상의 차이를 보였다. 3. 성별에 따라 DMFT index를 비교한 결과 14세부터 남녀 간에 통계적으로 유의하였으나 결과는 모든 연령에서 여자가 남자보다 높게 나타났다. SiC index는 성별에 따른 통계적 유의성이 없었으며, 9세와 14세에서 약 1개 여자가 더 많게 나타났다. 4. 지역별 DMFT index를 비교한 결과 60대와 70세 이상에서 도시보다 전원지역이 더 높았다. SiC index는 60대에서 도시가 15.49, 전원지역이 17.04로 약 1.5개 정도 전원지역이 높았다. 이상의 결과를 볼 때 DMFT index는 연령이 증가할수록 성별의 차이를 보였으나 SiC index는 성별, 지역별 큰 차이를 보이지 않았다. 고위험군은 성별과 지역별 차이 없이 포괄적이고 집중적인 예방관리가 필요하며, 고위험군의 구강건강증진을 위한 구강보건정책이 수립되어야 한다.

• 한국초지조사료학회지
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• 제28권1호
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• pp.7-12
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• 2008

새로 도입된 목초 Festulolium(Festuca pratensis$\times$Lolium multiflorum) 3개 속간교잡종의 한해, 출수기, 도복, 재생력과 수량성 및 사료가치의 지역적응력과 생산력을 검정하여 국내재배 가능성을 검토하고자, 2005년 9월부터 2006년 7월까지 수원과 남원에서 수행한 연구결과는 다음과 같다. 시험교잡종의 내한성은 내한 다수성 이탈리안 라이그라스 화산101호에 비하여 Perun은 다소 강한 편이었으며 Boxer와 Fleurial은 대등하게 나타남에 따라 국내 재배 시 한해 문제는 전혀 없을 것으로 판단된다. 초장 및 도복은 표준품종과 비슷하나 Fleurial은 86cm로 다소 짧고 도복도 15%로 가장 적게 발생되었으며, 재생력은 모든 품종이 양호하였다. 그리고 출수기는 화산101호가 5월 24일에 비하여 Fleurial은 같았으나, Perun과 Boxer는 $1{\sim}3$일 늦은 중만숙성 교잡종들이었다. 화산101호의 청예 및 건물 평균수량은 85,910 kg/ha, 13,642kg/ha이었으나, 이에 비하여 시험교잡종들의 청예수량은 $3{\sim}11%$가 증가하였다. 건물수량은 Perun이 18%로 가장 많이 증수되었으며, Boxer와 Fleurial은 화산101호와 대등하였다. 사료가치에서 조단백질 함량은 화산101호가 12.1%인데 비해 Perun이 16.6%로 가장 높았으며 Boxer와 Fleurial이 각각 14.7%와 14.3%이었다. 시험품종들의 NDF와 ADF는 모든 품종에서 각각 55.5%와 31.5% 미만으로서 양질 조사료의 요건을 갖추고 있는 것으로 나타났으며, 가소화 건물소화율에서도 표준품종의 65.1% 보다 시험품종들이 높게 나타났으므로 이들 품종은 모두 내한 중만숙 다수성 교잡종들로 판단된다.

• 생물환경조절학회지
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• 제24권3호
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• pp.226-234
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• 2015

본 연구에서는 적설하중 산정을 위한 노출계수를 결정하는데 필요한 기초자료를 제공하기 위하여 각국의 온실구조설계기준에서 제시된 노출계수들을 비교분석하였고 우리나라의 각 지역별 노출계수를 결정하고 결정방법에 대하여 개선방안을 분석하였으며 연구결과를 요약하면 다음과 같다. 각국의 노출계수 기준을 비교분석한 결과 노출계수에 영향을 미치는 주요인자는 노풍도, 풍속, 바람막이의 유무인 것으로 분석되었다. 또한 일본을 제외한 각국의 기준을 종합하면 노출계수는 3가지 단계로 구분되며 바람에 완전히 노출되고 바람이 센 지역의 노출계수는 0.8(0.9), 바람에 부분적으로 노출된 지역은 1.0(1.1), 바람막이가 조밀하게 설치된 지역은 1.2로 나타낼 수 있다. 따라서 온실의 적설하중 산정을 위한 노출계수는 적용의 용이성을 고려한다면 3단계로 구분하여 제시하는 것이 바람직할 것으로 판단된다. ISO 4355기준에 따라 우리나라 94개 지역에 대한 노출계수를 산정한 결과 대관령 (0.5)과 여수(0.6)를 제외한 모든 지역의 노출계수가 1.0과 0.8 두 가지로 대별되었다. 우리나라의 내륙지역이 해안지역에 비해 상대적으로 더 큰 강설 확률을 가지며 최대풍속이 $5m{\cdot}s^{-1}$ 이상인 일수가 더 작은 것으로 분석되었다. 우리나라의 노출계수는 3단계로 구분하여 해안 지역을 중심으로 한 바람이 강한 지역을 0.8로 하고 내륙지역은 1.0으로 하며 촘촘한 바람막이가 있는 경우는 일본을 제외한 각국에서 적용하고 있는 값인 1.2로 결정하는 것이 바람직할 것으로 판단되며, 임계풍속 $5.0m{\cdot}s^{-1}$ 이상 일 수에 따른 지역별 구체적인 노출계수는 추가적인 연구를 통해 결정할 필요가 있다.