• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.37 no.4
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• pp.347-357
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• 2024

Oxide semiconductor gas sensors are widely used for detecting toxic, explosive, and flammable gases due to their simple structure, cost-effectiveness, and potential integration into compact devices. However, their reliable gas detection is hindered by a longstanding issue known as humidity dependence, wherein the sensor resistance and gas response change significantly in the presence of moisture. This problem has persisted since the inception of oxide semiconductor gas sensors in the 1960s. This paper explores the root causes of humidity dependence in oxide semiconductor gas sensors and presents strategies to address this challenge. Mitigation strategies include functionalizing the gas-sensing material with noble metal/transition metal oxides and rare-earth/rare-earth oxides, as well as implementing a moisture barrier layer to prevent moisture diffusion into the gas-sensing film. Developing oxide semiconductor gas sensors immune to humidity dependence is expected to yield substantial socioeconomic benefits by enabling medical diagnosis, food quality assessment, environmental monitoring, and sensor network establishment.

• Environmental Analysis Health and Toxicology
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• v.27
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• pp.13.1-13.10
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• 2012

Objectives: We aimed to investigate the acute effects of heat stress on body temperature and blood pressure of elderly individuals living in poor housing conditions. Methods: Repeated measurements of the indoor temperature, relative humidity, body temperature, and blood pressure were conducted for 20 elderly individuals living in low-cost dosshouses in Seoul during hot summer days in 2010. Changes in the body temperature, systolic blood pressure (SBP) and diastolic blood pressure (DBP) according to variations in the indoor and outdoor temperature and humidity were analyzed using a repeated-measures ANOVA controlling for age, sex, alcohol, and smoking. Results: Average indoor and outdoor temperatures were $31.47^{\circ}C$ (standard deviation [SD], $0.97^{\circ}C$) and $28.15^{\circ}C$ (SD, $2.03^{\circ}C$), respectively. Body temperature increased by $0.21^{\circ}C$ (95% confidence interval [CI], 0.16 to $0.26^{\circ}C$) and $0.07^{\circ}C$ (95% CI, 0.04 to $0.10^{\circ}C$) with an increase in the indoor and outdoor temperature of $1^{\circ}C$. DBP decreased by 2.05 mmHg (95% CI, 0.05 to 4.05 mmHg), showing a statistical significance, as the indoor temperature increased by $1^{\circ}C$, while it increased by 0.20 mmHg (95% CI, -0.83 to 1.22 mmHg) as outdoor temperature increased by $1^{\circ}C$. SBP decreased by 1.75 mmHg (95% CI, -1.11 to 4.61 mmHg) and 0.35 mmHg (95% CI, -1.04 to 1.73 mmHg), as the indoor and outdoor temperature increased by $1^{\circ}C$, respectively. The effects of relative humidity on SBP and DBP were not statistically significant for both indoor and outdoor. Conclusions: The poor and elderly are directly exposed to heat waves, while their vital signs respond sensitively to increase in temperature. Careful adaptation strategies to climate change considering socioeconomic status are therefore necessary.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.5
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• pp.586-596
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• 1998

The relevance and importance of buffalo production under coconut plantations in the North Westen Province of Sri Lanka was studied in three districts (Bingiriya, Pannala, Kuliyapitiya). The objective of the study was to collect baseline information on socioeconomic and cultural aspects of buffalo production, with a view to promote and disseminate new technologies. The survey technique used consisted of a formal survey using a structured questionnaire (71 households) and rapid appraisal (55 households). The results indicate the existence of a wide stratification of dariy farmers which ranged from skilled dairy operators with high levels of production and management of efficiency to marginal subsistence farmers with low levels of productivity. The most frequent family size of households ranged from 4-5 members (58%), and the average family size was 4.7. The actual average land ownership accounts to 2.4 ha of upland and 0.5 ha of lowland, but when their accessibility to common property resources are taken into account, the land availability was assessed at 13 ha and 0.7 ha of upland and lowland, respectively. The highest average monthly income (Rs. 13,590) was received by farmers with off-farm employment (primary) who are also engaged in livestock production (secondary), and livestock contributed 43% of the total income. Livestock farmers who practised integrated crop farming as a secondary source of income received a monthly income of Rs. 10,843, and those involved in crop production as the primary source received the lowest average income (Rs. 7,295). The survey revealed a high investment cost on concentrate feeds (47%) for milk production. However some farmers obtained higher milk yields (11 litres/cow/day) at lower ration costs, and this could be attributed to the entrepreneurship skills and management efficiency. The study area had a well developed market infrastructure for fresh milk, principally due to the existence of the Nestle's company and the Coconut Triangle Milk Union. On an average the producer collected Rs. 10 per litre of milk marketed.

• Journal of Korean Society of Forest Science
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• v.81 no.3
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• pp.280-286
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• 1992

When the social cost-benefit analysis is applied for analyzing the public forestry investment, the choice of discount rate to be used in analysis is critical. In this paper, the social discount rate discussed in the public economics was introduced and the social time preference rate as a measure of that was estimated for Korea. The component parameters of the model used are : the elasticity of social marginal utility of consumption and the growth rate of real consumption. The results for the social time preference rate and the elasticity of social marginal utility of consumption are 6.2% and -1.38, respectively, which are plausible and thus can be used as a useful basis in establishing rational resource allocation policies.

• Journal of Korean Society of Transportation
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• v.19 no.3
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• pp.19-32
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• 2001

A parking facility choice model. which can be applied to analyze of the driver's parking behavioral changes in response to the local government's parking policy changes and to predict parking demand by the facility types, is developed. Under the context of the stated preference discrete choice model, socioeconomic variables and parking alternative characteristic variables are introduced as explanatory variables. A parking facility choice model for the shopping trip purpose is derived using multinomial logit model and nested logit model and the stated preference data collected in Taegu metropolitan area. The result shows that the sign of all the estimated parameters are logically consistent and the model's goodness of fit is reasonably good. As a result of the elasticity analysis of the model, the elasticity of parking cost is highest, and the elasticity of walking distance between parking place and the destination is higher than parking place searching and ingress time. This means that the parking places are supplied around the destination in the form of small-size parking place. The findings in this study is expected to provide a fundamental data for various short-term parking policy analyses and for parking facility's demand estimations.

• The Journal of Fisheries Business Administration
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• v.38 no.3
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• pp.67-88
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• 2007

This study is to estimate the factor weights for a successful sea-ranching project using the Analytical Hierarchy Process. Furthermore, it investigates the policy implications revealed by the differences in group opinions throughout fishermen, government officials, researchers and the scholars when the weights are assessed. The hierarchy is constructed for the 3 levels of factors which must be evaluated for a successful sea-ranching project. The top level of factors is divided by the ecological factors and the socioeconomic factors. As the middle level of factors, there are 3 factors such as the choice of fish, the habitat environment and the production technology under the ecological factors and another 3 factors such as the stability of fishery society, economic factors, and the law & system under the socio-economic factors. And then, at the bottom level of the hierarchy, the economic factors have two different sub-factors such as the fishing revenue and cost. The law & system has also 3 sub-factors such as the accessibility to sea-ranching area, fishing method, and surveillance. The fishermen and government officials show us quite opposite tendencies in assessments of the weights while both the researchers and scholars reveal almost the same opinions positioned at somewhere between first two groups. The study also reports the evaluations of efficiency measures for resource recovery methods among the sea-ranching project, artificial reef, release of fish seeds, and marine protection area. Both the sea-ranching project and marine protection area have the same efficiency in terms of resource recovery while the artificial reef and release of fish seeds are revealed as somewhat less efficient methods comparing to the former two methods.

• Journal of Korean Society of Transportation
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• v.17 no.5
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• pp.19-32
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• 1999

In this study, the trip characteristics of workers in the city are systematically analyzed. The trip behaviors and socioeconomic characteristics of workers are analyzed using Person Trip Survey Data of 1988 and 1992 in Taegu Metropolitan area. With the results of behavioral analyses, the daily travel pattern of workers is shown as one tour contained two trips and it is relatively simple and stable. Also the rate using the same mode in a day is Presented as high ratio. So, it can be explained that the choice of worker\`s first trip is fixed his/her travel mode for his/her daily travel mode. Based on these analyses, the mode choice model for workers is developed by applying the Multi-nominal Logit Model with the choice set of bus, taxi, and car. The explanatory variables of this model include sex, age, auto, travel time, and cost. Empirical tests of the model show encouraging results. After that, the temporal transferability of the model is examined by the Pairwise t-test and five indexes far the model of 1988 and 1992. The results of examination are satisfied with each significance level of the explanatory variables and five indexes. Therefore. it can be concluded that the temporal transferability of this model developed in this study is resonable.

• Ocean and Polar Research
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• v.26 no.4
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• pp.635-646
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• 2004

Chronic outbreaks of green tide in the Nakdong estuary toll a heavy socioeconomic cost. The paper investigates the influence of sediments on the nitrogen eutrophication, being claimed as the primary cause of green tide. To measure the flux of nitrate at the sediments-water interface, sediment cores were taken in Jan., Mar., May and Sep., 2000 at Noksan located in the West-Nakdong river estuary. The dissolved oxygen was profiled and then the pore water was extracted in situ. Core samples were analyzed for their textural characteristics. Cores were incubated by a novel technique to measure the fluxes of nitrate $(NO_3^-)$ and ammonia $(NH_4^+)$ at the sediment-water interface. The dissolved oxygen was depleted usually within several millimeters in the top sediments. Nitrate started to decrease drastically at the layer where dissolved oxygen was nearly depleted. Nitrate was also exhausted within several centimeters, followed by ammonia build up rapidly. The flux at the sediments-water interface calculated from the pore water concentrations revealed that nitrate was removed from the water column into the sediments. The sediment incubation experiment confirmed the above result. On the other hand ammonia were released from the sediment to the water column. As the incubation went on, however, the nitrate concentration in the overlying water was dropped below that of a top sediment. Then the flux is reversed, i.e., nitrate was released from the sediments to the water column. The implication is that the sediment can supply nitrate to the water column if it falls below a certain level. Thus it is likely that sediments in the eutrophicated river buffers the nitrate concentration in the water column, which leads to a prolonged green tide.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.6
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• pp.2663-2667
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• 2012

Objectives: An attempt was made to understand the nicotine dependence of smokers selected for an ongoing smoking cessation intervention programme in rural Kerala, India. Methods: Data were collected from resident males in the age group of 18 to 60 years from 4 randomly allocated community development blocks of rural Thiruvananthapuram district (2 intervention and 2 control groups). Trained accredited social health activist workers were utilised to collect data from all groups through face to face interview. Nicotine dependence among participants was assessed by means of the six-item Fagerstrom Test for Nicotine Dependence (FTND) translated into the local language. The internal consistency of FTND was computed using Cronbach's alpha coefficient. Criterion validity (concurrent) was assessed by correlations of nicotine dependence scores with age at initiation of smoking and cumulative smoking volume in pack-years. Results: Among the 928 smokers identified, 474 subjects were in the intervention area (mean age = 44.6 years, SD = 9.66 years) and 454 in the control area (mean age = 44.5 years, SD = 10.30 years). The overall FTND score among current daily smokers was 5.04 (SD: 5.05). FTND scores in the control and intervention areas were 4.75 (SD: 2.57) and 4.92 (SD: 2.51) respectively. The FTND scores increased with age and decreased with higher literacy and socioeconomic status. The average FTND score was high among smokers using both bidi and cigarettes (mean 6.10, SD 2.17). Internal consistency analysis yielded a Cronbach's alpha coefficient of 0.70 in a subsample of 150 subjects, a moderate result. The association of the scale was strongest, with the number of pack-years smoked (rho = 0.677, p < 0.001). Conclusion: A moderate level of nicotine dependence was observed among smokers in the current study. Tobacco cessation strategies could be made more cost effective and productive if a baseline assessment of nicotine dependence is completed before any intervention.

• KCID journal
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• v.18 no.2
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• pp.33-42
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• 2011

Climate change has impacts on not only the average temperature rise but also the intensity and frequency of extreme events such as flood and drought. It is also expected that the damages on agricultural infrastructure will be increased resulting from increased rainfall intensity and frequency caused by climate change. To strengthen the climate change adaptation capacity, it is necessary to identify the vulnerability of a given society's physical infrastructures and to develop appropriate adaptation strategies with infrastructure management because generally facilities related to human settlements are vulnerable to climate changes and establishing an adaptive public infrastructure would reduce the damages and the repair cost. Therefore, development of mitigation strategies for agricultural infrastructure against climatic hazard is very important, but there are few studies on agricultural infrastructure vulnerability assessment and adaptation strategies. The concept of vulnerability, however, is difficult to functionally define due to the fact that vulnerability itself includes many aspects (biological, socioeconomic, etc.) in various sectors. As such, much research on vulnerability has used indicators which are useful for standardization and aggregation. In this study, for the vulnerability assessment for agricultural infrastructure, 3 categories of climate exposure, sensitivity, and adaptation capacity were defined which are composed of 16 sub-categories and 49 proxy variables. Database for each proxy variables was established based on local administrative province. Future studies are required to define the weighting factor and standardization method to calculate the vulnerability indicator for agricultural infrastructure against climate change.