• 대한지리학회지
• /
• 제28권4호
• /
• pp.285-297
• /
• 1993

디 퓨전 공식은 사면의 변화를 측정하여 지형의 변화를 측정하고 과거의 지형환경을 복원하는 하나의 방법이다. 주로 구조지형에 적용되어 왔으나 최근에는 해안, 빙하, 단구 등의 지형에 도 적용되고 있다. 특정한 지각변화나 지형변화 후에 규칙적인 사면의 변화를 가정하여 지 형변화의 정도, 지형변화된 시간을 예측한다. 기본적인 가정으로는 균일한 물질, 비교적 폐 쇄적인 시스템, 규칙적인 사면변화가 요구된다. 근래에는 이러한 조건을 벗어나는 경우에도 조심스럽게 적용되고 있다. 급격한 변화를 가진 사면은 짧은 시간내에 안식각을 얻게되며 이때부터 디퓨젼 공식이 적용된다. 그리하여 현재 최대 사면각을 측정하여 안식각으로부터 의 변화량이나 혹은 소모된 시간(사면연대)를 알아낸다. ct, 즉 사면삭박률과 사면연령의 합 으로 주로 공식으로부터 계산되므로 ct 둘 중 하나를 알아내면 유용한 지형연대측정법이 된 다. 따라서 기준이 될 수 있는 사면의 연대가 조사되면 그 사면의 지표물질의 특징을 알 수 있고, 지표물질상의 비교가 가능한 곳에서는 상대적인 연대가 측정 가능하다. 삭박률은 초기 의 안식각, 사면의 높이, 현재의 사면각, 일사의 방향에 따라 민감한 반응을 보이므로 유의 해야 한다. 시뮬레이션에 있어서,현재 사면각과 사면의 높이 사이를 나타내는 그래프가 디퓨 젼공식으로부터 얻어지는 데 여기에서 여러 지역의 사면각의 연령차이를 예측할 수 있고 현 재의 사면각과 알려진 연령간의 그래프에서는 각 지역 사면의 물질적인 특징을 알 수 있다. 디퓨젼 모델은 대체적인 기본 가정을 지키면 지형변화를 기술하거나, 물질의 특징이나 기후 변화를 어느 정도 알 수 있고, 따라서 과거의 환경을 복원하는 지형적 연대측정의 한 방법 이 된다.한 변화에 대한 대응책으로 한국 기업은 선진국으로부터 관세와 쿼터 규 제를 받지 않는 주변의 개발도상국에 부품생산 공장을 건설하였다. 부품생산 공장의 입지변 화는 선진국의 무역규제를 우회적으로 회피할 뿐만 아니라 동시에 개도국의 저렴한 노동력 을 활용하기 위한 것이었다. 보다 최근에 한국 기업의 해외직접투자는 피투자국(host countries)의 내수시장과 값싼 노동력을 이용하기 위하여 인도네시아와 중국과 같은 여타의 개도국에 집중되고 있다, 이러한 입지변화는 한국 기업의 대 선진국 직접투자의 수익율이 극히 저조한 데 기인한 것이다. 우리나라 해외직접투자 기업의 이와 같은 입지변화 (선진 자본주의 국가$\longrightarrow$선진국 주변의 개도국$\longrightarrow$기타 개도국)는 해외직접투자가 하나의 지배적인 요 인보다는 다양한 요인에 의해 영향받는 것을 암시하고 있다. 더구나 한국 기업은 선진국 기 업에 비해 극히 제한된 기업특유의 우수요소만을 갖고 있기 때문에 한국 기업의 해외직접투 자는 선진국 기업의 그것과 분명히 다른 특성을 보이고 있다. 하기만 이는 기존의 직접투자 이론이 개도국기업의 다양한 해외직접투자를 설명하는 데 전혀 도움이 되지못한다는 것을 의미하는 것은 아니다. 실제로 기존의 직접투자 이론은 한국 기업에 의한 개도국에의 직접 투자를 잘 설명하고 있다. 직접투자를 통하여 적정 수준의 이윤을 실현하기 위해서는 기업 특유의 우위요소를 확보하는 것이 가장 중요하므로 선진국 기업과 개도국 기업에 의한 해외 직접투자는 장기적인 관점에서 볼 때 커다란 차이를 나타내지 않는다. 본 연구가 발견한 핵 심적인 내용은 해외직접투자 기업이 조직의

• 생명과학회지
• /
• 제17권10호
• /
• pp.1315-1320
• /
• 2007

미니돼지의 긴 뼈의 뼈끝(epiphysis) 성장에 대한 연구를 위해 상완골, 요골, 척골, 대퇴골, 경골의 근위 및 원위 뼈끝 부위를 중심으로 방사선 촬영을 실시하였다. 실험에 이용된 미니돼지의 연령대는 4주, 8주, 12주, 20주, 40주, 48주, 96주, 144주령으로 총 58마리였다. 뼈 성장과정에 대한 평가는 Owada & Sutow가 제안한 11가지 기준을 토대로 하였다. 긴 뼈에서 이차뼈발생중심은 4주령에서 40주령까지 빠른 성장을 보였고, 그 이후 96주령까지는 초기보다 느린 성장을 보였다. 가장 빠른 뼈끝 유합시기는 96주령으로 근위 요골, 근위 및 원위 대퇴골에서 관찰되었다. 미니돼지의 일반적인 긴 뼈의 완전한 뼈끝 유합은 144주령에 나타났으며 근위 상완골, 근위 및 원위 척골, 원위 요골, 그리고 근위 경골에서 관찰되었다.

• Journal of Preventive Medicine and Public Health
• /
• 제38권3호
• /
• pp.283-290
• /
• 2005

Objectives : The aim of this paper was to examine the relationship between the summertime (June to August) heat index, which quantifies the bioclimatic apparent temperature in sultry weather, and the daily disease-related mortality in Seoul for the period from 1991 to 2000. Methods : The daily maximum (or minimum) summertime heat indices, which show synergetic apparent temperatures, were calculated from the six hourly temperatures and real time humidity data for Seoul from 1991 to 2000. The disease-related daily mortality was extracted with respect to types of disease, age and sex, etc. and compared with the time series of the daily heat indices. Results : The summertime mortality in 1994 exceeded the normal by 626 persons. Specifically, blood circulation-related and cancer-related mortalities increased in 1994 by 29.7% (224 persons) and 15.4% (107 persons), respectively, compared with those in 1993. Elderly persons, those above 65 years, were shown to be highly susceptible to strong heat waves, whereas the other age and sex-based groups showed no significant difference in mortality. In particular, a heat wave episode on the 22nd of July 2004 ($>45^{\circ}C$ daily heat index) resulted in double the normal number of mortalities after a lag time of 3 days. Specifically, blood circulation-related mortalities, such as cerebral infraction, were predominant causes. Overall, a critical mortality threshold was reached when the heat index exceeded approximately $37^{\circ}C$, which corresponds to human body temperature. A linear regression model based on the heat indices above $37^{\circ}C$, with a 3 day lag time, accounted for 63% of the abnormally increased mortality (${\geq}+2$ standard deviations). Conclusions : This study revealed that elderly persons, those over 65 years old, are more vulnerable to mortality due to abnormal heat waves in Seoul, Korea. When the daily maximum heat index exceeds approximately $37^{\circ}C$, blood circulation-related mortality significantly increases. A linear regression model, with respect to lag-time, showed that the heat index based on a human model is a more dependable indicator for the prediction of hot weather-related mortality than the ambient air temperature.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제14권4호
• /
• pp.1721-1737
• /
• 2020

Human apparent age estimation has become a popular research topic and attracted great attention in recent years due to its wide applications, such as personal security and law enforcement. To achieve the goal of age estimation, a large number of methods have been pro-posed, where the models derived through the cumulative attribute coding achieve promised performance by preserving the neighbor-similarity of ages. However, these methods afore-mentioned ignore the geometric structure of extracted facial features. Indeed, the geometric structure of data greatly affects the accuracy of prediction. To this end, we propose an age estimation algorithm through joint feature selection and manifold learning paradigms, so-called Feature-selected and Geometry-preserved Least Square Regression (FGLSR). Based on this, our proposed method, compared with the others, not only preserves the geometry structures within facial representations, but also selects the discriminative features. Moreover, a deep learning extension based FGLSR is proposed later, namely Feature selected and Geometry preserved Neural Network (FGNN). Finally, related experiments are conducted on Morph2 and FG-Net datasets for FGLSR and on Morph2 datasets for FGNN. Experimental results testify our method achieve the best performances.

• 치위생과학회지
• /
• 제24권1호
• /
• pp.1-8
• /
• 2024

Background: Oral frailty is defined as the functional decline of the oral function due to aging, and it is associated with frailty and chronic disease. Most of the frailty intervention is for adults aged 65 years and older. However, early intervention for preventive disorder is most important. The objective of this study was to identify the age at which oral frailty surpass the "normal" range. Methods: This cross-sectional study included 719 adults (aged 30~89 years) residing in Gangwon province in May 2023. Risk of oral frailty was assessed using criteria from The Korean Academy of Geriatric Dentistry including oral function such as swallowing and mastication, and frailty. Frailty was assessed using the Kihon Checklist. To determine when oral frailty surpass the "normal" status, statistical analysis including chi-squared tests and multiple logistic regression analysis were performed using R (ver. 4.3.1). Results: There were 388 (54.0%) individuals who had a "normal" status risk of oral frailty. The risk of oral frailty was higher in the 50~54 age group compared to the 30~34 age group (odds ratio [OR] 0.50, 95% confidence interval [CI] 0.28~0.91), after adjusting for gender, education, income, occupation, and frailty (OR 0.46, 95% CI 0.22~0.94). This means that from 50~54 years old, regardless of gender, education, income, occupation, or frailty condition, there is a distinction from the "normal" status. Conclusion: We found that intervention for oral frailty is needed starting from age 50 years. This is the stage where early indications of oral frailty become apparent. Early intervention for oral frailty can lead to a decrease in the prevalence of diseases and medical expenditure. Therefore, early intervention in middle-aged adults of oral frailty is necessary to improve the quality of life related to oral health.

• 암석학회지
• /
• 제7권2호
• /
• pp.69-76
• /
• 1998

옥천대 남서부지역에 분포하는 화강편마암과 광주화강암에서 분리한 각섬석과 백운모의 40Ar/39Ar 분석자료는 다음과 같은 지구조적 의미를 가진다. 이들 시료의 40Ar/39Ar 분석치는 모두 뚜렷한 연령 스펙트럼을 보이며 특히 방출된 39Ar 가스의 60% 이상으로 만들어진 37Arca/39Ark과 38Arcl/39Ark 프라토우(plateau)가 뚜렷하다. 각섬석에 대한 36Ar/40Ar 대 39Ar/40Ar 의 대비도는 시료 HN-100을 제외하고는 모두 뚜렷한 연령 프라토우를 보여준다. 고온단계에서 37Arca/39Ark 값은 38Arcl/39Ark 값의 상대적인 증가에 따른 불규칙성은 판상광물 사이에 들어있던 알곤 가스의 방출에 의한 것으로 추정된다. HN-100은 40Ar/39Ar 전체 알곤가스 연령이 918 Ma로서 저온단계에서 알곤 방출이 있었고 고온단계에서 1360 Ma를 보인다. 전자는 대보운동에 의한 영향을 받은 시기이며, 후자는 선캠브리아기 화강편마암에 포획된 각섬석 결정이 폐쇄온도(약 $500\pm$$50^{\circ}C$)에 도달한 시기를 보여준다. 광주화강암류의 세 암상(각섬석 흑운모 화강섬록암, 흑운모 화강섬록암과 복운모 화강암)이 보이는 165 Ma를 전후한 연령은 저온단계에서 얼마간의 알곤가스 방출이 있었으며 또 기발표된 Rb/Sr 전암년령과 비교하여 젊은 년령을 보이는 것으로 미루어 이 시기는 대보운동의 영향을 받은 시기로 생각된다. 이들 40Ar/39Ar 광물년령과 기발표된 Rb/Sr 전암년령 및 K/Ar 광물년령은 옥천대 남서부지역이 100~150 m/m.y.의 느린 속도로 그리고 산이반도 지역은 100 m/m.y. 이하의 보다 느린 속도로 상승했음을 알려준다. 이 지역에서 가장 강력했던 지각변동 또는 화성활동은 원생대 중기(1360 Ma 전후)와 중생대 쥬라기 중기(약 165 Ma 전후)에 있었다.

• 한국학교보건학회지
• /
• 제1권1호
• /
• pp.114-132
• /
• 1988

Aiming to appraise student's health status and recommend improvement and strengthening of the school health services, statistical analysis of the results of health examination were done with summarized data which were collected nation-wide through the Ministry of Education. After analysis of data obtained, the results of the study summarized as follows; 1) Requested Adequate care Requested Adequate care showed from 5 % to 3% in 1962 and 1984 respectively. In sexes, Requested Adequate in girls (2.8%) more apparent than in boys (2.5%) 2) Eyes i) Weak vision, abnormal refraction of eyes (myopia, hypermetropia and astigmatism), eye diseases (trachoma, others) were found as shown in the Table 2, Figure 3. Weak vision and abnormal refraction of eyes showed from 2 % (Elementary), 5 % ( Secondary) to 4 % (Elementary), 14 % (Secondary) in 1962 and 1984 respectively. In both sexes, the older the age of students the more weak vision and abnormal refraction of eyes had rapidly increased especially in over 15-year old. ii) Eye diseases (trachoma, others) showed from 2% to age of students the more diseases had students. 3) Ear, nose and pharynx Hearing disturbance, ear diseases (otitis mediae, others), nose (empyema, hypertrophy) and pharynx diseases were found as following 1) Hearing disturbance was found from 0.3%(Elementary), 1 %(Secondary) to 0.05 % (Elementary), 0.4 % (Secondary) in 1962 and 1984 respectively, however, recently the older the age of students the more had students. ii) Ear diseases showed from 1.7 % (Elementary) 1.0 % (Secondary) to 0.3 %(Elementary), 0.5%(Secondary) in 1962 and 1984 respectively. iii) In diseases of the nose and pharynx, tonsilitis showed from 2.5% (Elementary), 3.5 % (Secondary) to 1.8 % ( Elementary). 2.5% (Secondary) in 1962 and 1984 respectively. 4) Skin Infectious skin diseases and other skin diseases were found from 1.5% to 0.6% in 1962 am 1984 respectively. 5) Teeth Dental caries (in milk and permanent teeth) and otner oral diseases are shown from 12 % (Elementary), 8%(Secondary) to 75%( Elementary), 25% (Secondary) in 1962 and 1984 respectively. 6) Other defects and diseases A relatively higher morbidity was shown in the tubercular diseases, in anemia, and in heart diseases among the tuberculous diseases, nodular diseases, Pleurisy, heart diseases, anemia, beriberi, hernia, neurasthenia, speech difficulty, mental disorders, bone dysformity, motion difficulty of extremities. In both sexes, tuberculous diseases were found almost equally in both sexes and anemia in girls was more apparent than in boys. Trying to provide more effective health services in schools : i) A better and more effective physical examination should be carried out in each school and prior to the physical examination, the qualified daily observation of children by teacher should be keenly practiced. ii) According to the results of the required annual physical examination the leading cause of morbidity were dental caries, myopia, angina and otitis mediae and fore these diseases follow up should be carried out. iii) For prevention and treatment of diseases and defects health education for students in the classroom as well as to parents is urgently requested.

• Smart Structures and Systems
• /
• 제12권1호
• /
• pp.41-54
• /
• 2013

Concrete is known as a heterogeneous product which is composed of complex chemical composition and reaction. The development of concrete thermal effect during early age is critical on its future structural health and long term durability. When cement is mixed with water, the exothermic chemical reaction generates hydration heat, which raises the temperature within the concrete. Consequently, cracking may occur if the concrete temperature rises too high or if there is a large temperature difference between the interior and the exterior of concrete structures during early age hydration. This paper describes the contribution of novel Fabry-Perot (FP) fiber optic temperature sensors to investigate the thermal effects of concrete hydration process. Concrete specimens were manufactured under various water-to-cement (w/c) ratios from 0.40 to 0.60. During the first 24 hours of concreting, two FP fiber optic temperature sensors were inserted into concrete specimens with the protection of copper tubing to monitor the surface and core temperature change. The experimental results revealed effects of w/c ratios on surface and core temperature developments during early age hydration, as well as demonstrating that FP fiber optic sensors are capable of capturing temperature variation in the concrete with reliable performance. Temperature profiles are used for calculating the apparent activation energy ($E_a$) and the heat of hydration (H(t)) of concrete, which can help us to better understand cement hydration.

• 한국환경보건학회지
• /
• 제40권1호
• /
• pp.17-26
• /
• 2014

Background: Despite children's unique characteristics that distinguish them from adults, relatively few attempts have been made to measure exposure factors for characterization of children's exposure to hazardous chemicals in child-specific products (CSP). This study was conducted to establish the child-specific exposure factors for exposure and risk assessment of hazardous substances in CSP. Methods: We investigated the exposure factors (e.g., time use of child-products, time and frequency of object-to-body contact, time and frequency of object-to-mouth contact) influencing children's exposure to CSP (e.g., toys, playmats, oil pastels, etc.) in 650 children through a parent-completed questionnaire using a web-based survey. Participants were recruited in five age groups, <1, 1-2, 2-3, 3-6, and 6-12 years of age. Results: The child-specific exposure factors were presented as the mean, median, $95^{th}$ percentile, minimum, and maximum values. Time activity for play mats was the longest among CSP and infants spent more time on them than did elder age groups (189.3-224.7 min/day for <1-2 years vs. 91.2 min/day for 6-12 years). It is apparent that time and frequency of toy block- and plastic toy-to-mouth contact significantly decreased as a function of age. When the variation of CSP use patterns was compared by gender, the only variable that was statistically different between genders was time activity in child-products exposure space. Conclusion: We believe the five child-specific exposure factors suggested in the present study will be valuable for reducing uncertainty in the estimation of chemical exposure during risk assessment of CSP and furthermore, in the appropriate regulations to protect children's health.

• 복식문화연구
• /
• 제23권5호
• /
• pp.755-767
• /
• 2015

This study analyzed the body-type characteristics of 340 old-aged obese women that had been on the rise as a part of efforts to activate the silver clothing industry. The subjects were in the age range of 60-79 and met some obesity requirements, including a Rohrer Index of 1.6 or higher, a BMI of 25 or higher, and a WHR of 0.85 or higher. Old-aged obese women showed increased thickness of the torso with age, which suggests that they revealed the characteristics of regardless of gender. In other words, they became bigger in the waist and abdomen, shorter in height, slimmer in the lower body, and thicker in the torso. There are three types of obesity: Type 1 is lower-body obesity with a higher degree of obesity in the abdomen than the upper body. Type 2 is abdominal obesity with a higher degree of obesity in the upper body than in the lower body. Type 3 is whole-body obesity with balanced obesity of the whole body. As for changes to the types of obesity according to age, those who are in their sixties usually fall into the categories of upper-body and whole-body obesity, and those who are in their seventies are much more concentrated in the categories of abdominal obesity and upper-body obesity with a decreased percentage of whole-body obesity. It is apparent that the percentage of abdominal and upper-body obesity rises with age due to fat accumulation in the abdomen.