• 제목/요약/키워드: Aging period

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Modeling on the Sorption Kinetics of Lead and Cadmium onto Natural Sediments (퇴적물에서의 납과 카드뮴의 흡착 동력학 모델링)

  • Kwak, Mun-Yong;Ko, Seok-Oh;Park, Jae-Woo;Jeong, Yeon-Gu;Shin, Won-Sik
    • Korean Journal of Ecology and Environment
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    • v.39 no.4 s.118
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    • pp.450-461
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    • 2006
  • In this study, sorption kinetics of lead (Pb) and cadmium (Cd) onto coastal sediments were investigated at pH 5.5 using laboratory batch adsorbers. Four different models: one-site mass transfer model (OSMTM), pseudo-first-order kinetic model (PFOKM) ,pseudo-second-order kinetic model (PSOKM) and two compartment first-order kinetic model (TCFOKM) were used to analyze the sorption kinetics. As expected from the number of model parameters involved, the three-parameter TCFOKM was better than the two-parameter OSMTM, PFOKM and PSOKM in describing sorption kinetics of Pb and Cd onto sediments. Most sorption of Pb and Cd was rapidly completed within the first three hours, followed by slow sorption in the subsequent period of sorption. All models predicted that the sorbed amount at the apparent sorption ($q_{e,s}$) equilibria increased as the CEC and surface area of the sediments increased, regardless of initial spiking concentration ($C_0$) and heavy metal and the sediment type. The sorption rate constant ($k_s,\;hr^{-1}$) in OSMTM also increased as the CEC and BET surface area increased. The rate constant of pseudo-first-order sorption ($k_{p1,s},\;hr^{-1}$) in PFOKM were not correlated with sediment characteristics. The results of PSOKM analysis showed that the rate constant of pseudo-second-order sorption ($k_{p2,s},\;g\;mmol^{-1}\;hr^{-1}$) and the initial sorption rate ($v_{o,s},\;mg\;g^{-1}\;hr^{-1}$) were not correlated with sediment characteristics. The fast sorption fraction ($f_{1,s}$) in TCFOKM increased as CEC and BET surface increased regardless of initial aqueous phase concentrations. The sorption rate constant of fast fraction ($k_{1,s}=10^{0.1}-10^{1.0}\;hr^{-1}$) was much greater than that of slow sorption fraction ($k_{2,s}=10^{-2}-10^{-4}\;hr^{-1}$) respectively.

Comparative Review on the Introduction and Operation of Salary Peak System -Focusing on Korea and Japan- (임금피크제 도입운영에 관한 비교법적 검토 -한국과 일본을 중심으로-)

  • Noh, Jae-Chul
    • The Journal of the Korea Contents Association
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    • v.15 no.11
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    • pp.93-103
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    • 2015
  • In this study, it has an intention of arranging an implication based on an effective introduction of a wage peak system in Japan to settle a mandatory retirement at sixty according to a legalization of retirement age at sixty smoothly. Institutionally, retirement age guaranteed type that reduces wage from certain period before retirement is of great importance. In Japan, mainly features the extension of retirement age that focus on keeping aged employment after retirement. In the introduction of the wage peak system, Korea attaches importance to the wage cost savings, but Japan puts emphasis on using aging workforce. Korea wants to promote the aged employment for retirement age at 60, whereas Japan actively push ahead with retirement age 65 and after that time. South Korea needs to reinforce the pensionable age and the connection though the extension of retirement age via the manpower utilization, employment promotion and the stability. It is necessary to prepare a institutional plan to try not to make a gap of the pensions by guaranteeing or extending the retirement age connect to the age of pensioners though the wage peak system. To activate the wage peak system, it is necessary to acknowledge a legal improvement that concedes rational changes such as the rule of employment. An active interpretation is needed currently though, it is more necessary to review the stipulation and the rational changes of the rule of employment that is established by a precedent like the Japanese legislation case. When a disadvantageous change of works rules is made, it is able to consider establishing the provision in the Act on age Discrimination Prohibition in Employment and Aged Employment Promotion, therefore it won't be able to apply the regulation in the rational criterion that satisfies the standards, rather than amending a Article 94 of the Labor Standards Act that makes accepting the approval of the majority of workers.

The Effects of Female Wage on Fertility in Korea (여성의 임금수준이 출산율에 미치는 영향 분석)

  • Kim, Jungho
    • KDI Journal of Economic Policy
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    • v.31 no.1
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    • pp.105-138
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    • 2009
  • Although the decline in fertility rate is generally observed along the history of economic development throughout the world, the continuing decline hitting below the replacement level in Korea over the recent years gathered serious social concerns on the ground that it accelerates the process of population aging. The total fertility rate in Koreareached 2.08 in 1983, and gradually fell to the levels of 1.08 in 2005 and 1.26 in 2007. The policy debate over the role of the government has been focused mainly on the level of theoretical discussion without substantial basis on firm empirical evidence and the determinants of fertility. The objective of the paper is to empirically investigate the fertility effect of the female wage, which is understood as one of the most important determinants of fertility in Koreasince 1980 focusing on one aspect of fertility, namely birth spacing. Using the Korean National Fertility Survey conducted in 2006, I estimate a duration model of first and second births taking into account individual heterogeneity, which turned out to be an important factor to control for. Compared with previous studies in the literature on the Korean fertility, the study has an advantage of using the complete pregnancy history of women in a more representative sample. Unlike the previous studies, the analysis also deals with the endogeneity of marriage by treating a certain age, rather than age at marriage, as the time in which a woman becomes exposed to the risk of pregnancy. The study shares the common problem in the literature on birth spacing of lacking relevant wage information for respondents in a retrospective survey. I estimate the wage series as a function of the basic characteristics using the annual Wage Structure Survey from 1980 to 2005, which is considered as a nationally representative sample for wage information of employees. The results suggest that the increase in female wage by 10 percent leads to a decrease in second birth hazard by 0.56~0.92 percentage points and that the increase in spouse's wage by the equal amount is accompanied by the increase in second birth hazard by 0.36~1.13 percentage points. These estimates are more precisely estimated and of smaller magnitude than those presented by the previous studies. The results are robust to the different specifications of the wage equation. The simulation analysis based on the predicted values shows that about 17% of the change in the second birth hazard over the period 1980 to 2005 was due to the change in the female wage. Although there is some limitation in data, the results can be viewed as one estimate of the role of female wage on the recent fertility decline in Korea. The question raised by the paper is not a normative one of whether a government should promote childbearing but a positive one thatexplains fertility decline. Therefore, if there is a wide consensus on promoting childbearing, the finding suggests that the policies designed to reduce the opportunity cost of women in the labor market would be effective. The recent movement of implementing a wide range of family-friendly policies including child care support, maternity leave, parental leave and tax benefit in developed countries should be understood in this context.

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Radiation Therapy Results of Invasive Cervical Carcinoma Found After Inappropriate Hysterectomy (부적절한 수술루 침윤성 자궁경부암의 방사선치료 결과)

  • Choi Doo Ho;Kim Eun Seog;Nam Kae Hyun;Huh Seung Jae
    • Radiation Oncology Journal
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    • v.14 no.3
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    • pp.211-219
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    • 1996
  • Purpose : Hysterectomy without lymph node dissection was considered an inadequate treatment method for invasive uterine cervix cancer. Usually the procedure was performed inadvertently on patients who were thought to have benign or premalignant conditions preoperatively. We analysed radiotherapy results of such patients to evaluate survival rates, failure patterns and prognostic factors according to various conditions. Materials and Methods : Sixty one patients undergoing hysterectomy in the presence of invasive cervical carcinoma were reviewed retrospectively. Preoperative diagnosis were carcinoma in situ (38 cases), severe dysplasia (2), myoma (6), uterine bleeding (4), uterine prolapse (2). and early invasive cervix cancer (10) (One patient had myoma and carcinoma in situ coincidently). Patients received postoperative megavoltage radiotherapy from August 1985 to December 1993, and minimum follow-up period was 24 months. Eight patients received ICR only, 6 patients ICR and external radiation, and 47 patients received external radiation therapy only. Results : Overall 5-year survival rate and relapse-free survival rate werer $83.8\%$, $86.9\%$ respectively. For patients with retrospective stage IA, IB, IIB (gross residual after surgery), and vaginal cuff recurrence were $90.9\%$, $88.8\%$, $38.4\%$, and $100\%$ respectively There were 8 cases of treatment failure, most of them (5/8) were in patients with gross residual disease, other patients were full thickness involvement of cervix wall (2/8) except one. Patients with early vaginal cuff recurrence and microinvasive cervical cancer (stage IA) had no treatment related failure Prognostic factors affecting survival by univariate analysis were status of residual disease, tumor histology and retrospective stage. Conclusion : Adjuvant radiotherapy appeared to be effective treatment method for patients with presumed stage IA, IB and early local recurrent disease after inadvertent hysterectomy Survivals for patients with gross disease remained after inappropriate hysterectomy was poor, So, early cancer detection and Proper management with precise pretreatment s1aging is necessary to avoid inadherent hysterectomy especially in the cases of gross residual disease.

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Automatic Detection of Stage 1 Sleep (자동 분석을 이용한 1단계 수면탐지)

  • 신홍범;한종희;정도언;박광석
    • Journal of Biomedical Engineering Research
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    • v.25 no.1
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    • pp.11-19
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    • 2004
  • Stage 1 sleep provides important information regarding interpretation of nocturnal polysomnography, particularly sleep onset. It is a short transition period from wakeful consciousness to sleep. Lack of prominent sleep events characterizing stage 1 sleep is a major obstacle in automatic sleep stage scoring. In this study, we attempted to utilize simultaneous EEC and EOG processing and analyses to detect stage 1 sleep automatically. Relative powers of the alpha waves and the theta waves were calculated from spectral estimation. Either the relative power of alpha waves less than 50% or the relative power of theta waves more than 23% was regarded as stage 1 sleep. SEM (slow eye movement) was defined as the duration of both eye movement ranging from 1.5 to 4 seconds and regarded also as stage 1 sleep. If one of these three criteria was met, the epoch was regarded as stage 1 sleep. Results f ere compared to the manual rating results done by two polysomnography experts. Total of 169 epochs was analyzed. Agreement rate for stage 1 sleep between automatic detection and manual scoring was 79.3% and Cohen's Kappa was 0.586 (p<0.01). A significant portion (32%) of automatically detected stage 1 sleep included SEM. Generally, digitally-scored sleep s1aging shows the accuracy up to 70%. Considering potential difficulties in stage 1 sleep scoring, the accuracy of 79.3% in this study seems to be robust enough. Simultaneous analysis of EOG provides differential value to the present study from previous oneswhich mainly depended on EEG analysis. The issue of close relationship between SEM and stage 1 sleep raised by Kinnariet at. remains to be a valid one in this study.

Changes in Psoas Major and Quadriceps Cross Sectional Area in Elderly People after 12 Weeks of Exercise (고령자를 대상으로 12주간 운동이 대요근 및 대퇴부 근황단면적에 미치는 영향)

  • Tachi, Toshiki;Oguri, Kazuo;Torii, Suguru;Kobayashi, Kando;Fujii, Katsunori;Kim, Jun-Dong;Nho, Ho-Sung
    • Journal of Life Science
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    • v.21 no.1
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    • pp.1-8
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    • 2011
  • The purpose of this study was to investigate whether 12-weeks of movement training would increase the psoas major cross-sectional area (CSA) in senior men and women. Fifty eight men and women aged 65 to 80 years old ($69.6{\pm}3.7$, 30 male, 28 female) were divided into a control (n=19) and exercise group (n=39). Subjects were assessed before and after the training program for stature, body mass, and magnetic resonance imaging of the psoas major and the quadriceps muscle. The experimental group performed exercises using machines designed to improve the movement of the hip at a frequency of twice every week, with a total of 23 trainings in 12-weeks. Magnetic resonance images of both thighs and the abdomen and psoas major were obtained, aimed at 50% of the length of the greater trochanter and the lower edge of the femur and between the fourth (L4) and fifth (L5) lumbars. A 9.4% increase in the psoas major CSA in the training group was observed. In the male and female breakdown, a 11.5% and 8.4% change was observed in males and females, respectively. In the quadriceps, there was no significant statistical improvement in either males or females. Furthermore, in the control group, there was no significant change seen in either the psoas major or the quadriceps. As a result of conducting training that enables upkeep of posture and smooth linkage of the lumbar spine, the pelvis and thighbone, the psoas major CSA of older adults were improved in a short period of time. For this reason, the possibility of improving the psoas CSA, which decreases remarkably with increased age, by improving the linkage of the body trunk is also suggested.

A Study on Improvement of Laws regarding Welfare for the Aged (노인복지 관련법제의 발전방향)

  • Park, Ji-Soon
    • Journal of Legislation Research
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    • no.41
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    • pp.87-123
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    • 2011
  • Korea is expected to become an 'aged society' with more than 14 percent of the public aged 65 years or more by 2018. The rapid aging is giving rise to various problems within the society along with falling birthrate in a short period of time. In this context, the role and function of laws on welfare for the aged must be particularly emphasized. Also the Senior Citizens Welfare Act is of great importance as it provides social welfare service on the basis of functional connection with social insurance and public assistance. First, this paper looks into the history of laws related to welfare for the elderly such as the Senior Welfare Act, the Act on Long-term Care Insurance for Senior Citizens and the Basic Old Age Pension Act as well as the findings of earlier studies. In the second place, it will break down such laws by main components aiming to examine details of the laws and questions raised regarding them and to seek ways to achieve improvement with an emphasis on health care, old age income security, housing welfare(assisted living facilities), job security for the aged. The Senior Welfare Act offers substance of social welfare service for the elderly. Income security, health and medical care, welfare measures through long-term care and assisted living facilities, social participation by working are the key elements and all of them should be closely associated to ensure citizens get sufficient public support in their old age. For this purpose, the Senior Welfare Act is under a normative network with laws such as Act on Long-term Care Insurance for Senior Citizens and Basic Old Age Pension Act. Current laws on welfare for the aged including Senior Welfare Act are not sufficiently responsive to the aged society of the 21st century. Income security combined with decent social participation, health and medical care closely connected with long-term care system, efficient expense sharing between government and local government, enhancement of effectiveness of welfare measures can be considered as means to improve current welfare system so that the elderly can enjoy their old age with dignity and respect.

The Dynamics of CO2 Budget in Gwangneung Deciduous Old-growth Forest: Lessons from the 15 years of Monitoring (광릉 낙엽활엽수 노령림의 CO2 수지 역학: 15년 관측으로부터의 교훈)

  • Yang, Hyunyoung;Kang, Minseok;Kim, Joon;Ryu, Daun;Kim, Su-Jin;Chun, Jung-Hwa;Lim, Jong-Hwan;Park, Chan Woo;Yun, Soon Jin
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.23 no.4
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    • pp.198-221
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    • 2021
  • After large-scale reforestation in the 1960s and 1970s, forests in Korea have gradually been aging. Net ecosystem CO2 exchange of old-growth forests is theoretically near zero; however, it can be a CO2 sink or source depending on the intervention of disturbance or management. In this study, we report the CO2 budget dynamics of the Gwangneung deciduous old-growth forest (GDK) in Korea and examined the following two questions: (1) is the preserved GDK indeed CO2 neutral as theoretically known? and (2) can we explain the dynamics of CO2 budget by the common mechanisms reported in the literature? To answer, we analyzed the 15-year long CO2 flux data measured by eddy covariance technique along with other biometeorological data at the KoFlux GDK site from 2006 to 2020. The results showed that (1) GDK switched back-and-forth between sink and source of CO2 but averaged to be a week CO2 source (and turning to a moderate CO2 source for the recent five years) and (2) the interannual variability of solar radiation, growing season length, and leaf area index showed a positive correlation with that of gross primary production (GPP) (R2=0.32~0.45); whereas the interannual variability of both air and surface temperature was not significantly correlated with that of ecosystem respiration (RE). Furthermore, the machine learning-based model trained using the dataset of early monitoring period (first 10 years) failed to reproduce the observed interannual variations of GPP and RE for the recent five years. Biomass data analysis suggests that carbon emissions from coarse woody debris may have contributed partly to the conversion to a moderate CO2 source. To properly understand and interpret the long-term CO2 budget dynamics of GDK, new framework of analysis and modeling based on complex systems science is needed. Also, it is important to maintain the flux monitoring and data quality along with the monitoring of coarse woody debris and disturbances.

The Transmission Activities and characteristic of the Naeseo Traditional Folk art Conservation Association in Masan (마산 내서전통민속문화예술보존회의 전승 활동과 특징)

  • Choi, Ja-Un
    • (The) Research of the performance art and culture
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    • no.43
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    • pp.121-143
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    • 2021
  • The Aim of the this paper is to figure out impetus of the Naeseo Traditional Folk art Conservation Association. This Preservation Society derived from Hogaeri farmers' band. Through aging and hollowing out Hogaeri farmers' band got into a period of stagnation. In order to overcome slump villager and people of a township organized a conservation society in 1994. Members restored and directed folk song which from age to age for performance. are designated as cultural asset in 2017. Sutguldeong song is only song in inland area. This song are worthy of notice in . which is consist of various agricultural work songs experienced two changes. Rice-planting songs are characteristic. Especially, Executive playing a central role harden foundation of the Preservation Society. The mainspring of activity is the sense of responsibility. Preservation Society laying emphasis on recruiting new members. Preservation Society is planning to develop curriculum for Jurisdiction elementary and middle school students. This Preservation Society is made up of First generation members and Second generation members. First generation members who are born and bred in Hogaeri have been good friends both in joy and in sorrow Early days of Preservation Society. So, They has a strong family bond. In order to induce membership Members are practicing Nongak, popular folk songs, dancing program. Second generation members are not conversant with a folk song. Nonetheless They have a strong mind on a member line.

Effects of Temperature on the Development and Reproduction of Phaedon brassicae Baly (Coleoptera: Chrysomelidae) (좁은가슴잎벌레의 발육과 생식에 미치는 온도의 영향)

  • Jeong Joon Ahn;Kwang Ho Kim;Hong Hyun Park;Gwan Seok Lee;Jeong Hwan Kim;In-Hong Jeong
    • Korean journal of applied entomology
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    • v.62 no.4
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    • pp.315-323
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    • 2023
  • The brassica leaf beetle, Phaedon brassicae Baly (Coleoptera: Chrysomelidae), is one of the important pests infesting cruciferous vegetables. In order to understand the biological characteristics of the insect, we investigated the effects of temperature on development of each life stage, adult longevity and fecundity of P. brassicae at four constant temperatures of 15, 20, 25 and 27.5℃ for immature life stage and five constant different temperatures of 10, 15, 20, 25 and 27.5℃ for adult stage. Eggs and larvae successfully developed next life stage at temperature tested. The development period of egg, larva, and pupa decreased as temperature increased. Lower developmental threshold (LDT) and thermal constant (K) were calculated using linear regression as 8.7℃ and 344.73DD, respectively. Lower and higher threshold temperature (TL and TH) from egg to adult emergence were estimated by Briere function as 5.3℃ and 40.4℃, respectively. Adults produced eggs at the temperature range between 10℃ and 27.5℃, and showed an estimated maximum number, ca. 627.5 eggs at 21.7℃. Adult oviposition models including aging rate, age-specific survival rate, age-specific cumulative oviposition, and temperature-dependent fecundity were constructed. Temperature-dependent development models and adult oviposition models would be useful components to understand the population dynamics of P. brassicae and to establish the strategy of integrated pest management in cruciferous crops.