• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.4
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• pp.336-342
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• 2014

This study was conducted to estimate of the greenhouse gas inventory on forest land at provincial level. The greenhouse gas emissions are calculated according to the K-MRV guidance. We collected activity data from statistical yearbook of forestry and used default emission factors. The annual total $CO_2$ emission in forest land was -58,711Gg $CO_2eq.$ and the annual $CO_2$ emission in loss such as fellings, fuelwood and fire was 19,896Gg $CO_2eq.$ in 2011. The results showed the removals of carbon dioxide in the forest land, it's amount was -38,815Gg $CO_2eq.$ in 2011. Annual net $CO_2$ removal of local forest was highest in Kangwon province in 2011. Our study did not use the many statistics due to exclusion of double counting. There are need complementary activity data and emission factors, and then we will find a way to calculate the greenhouse gas emissions/removals in the near future.

• Journal of the Korean Operations Research and Management Science Society
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• v.1 no.1
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• pp.151-170
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• 1976

There are many cases of production processes which intermittently produce several different kinds of products for stock through one set of physical facility. In this case, an important question is what size of production run should be prduced once we do set-up for a product in order to minimize the total cost, that is, the sum of the set-up, carrying, and stock-out costs. This problem is used to be called scheduling of multiple products through a single facility in the production management field. Despite the very common occurrence of this type of production process, no one has yet devised a method for determining the optimal production schedule. The purpose of this study is to develop quantitative analytical models which can be used practically and give us rational production schedules. The study is to show improved models with application to a can-manufacturing plant. In this thesis the economic production quantity (EPQ) model was used as a basic model to develop quantitative analytical models for this scheduling problem and two cases, one with stock-out cost, the other without stock-out cost, were taken into consideration. The first analytical model was developed for the scheduling of products through a single facility. In this model we calculate No, the optimal number of production runs per year, minimizing the total annual cost above all. Next we calculate No$_{i}$ is significantly different from No, some manipulation of the schedule can be made by trial and error in order to try to fit the product into the basic (No schedule either more or less frequently as dictated by) No$_{i}$, But this trial and error schedule is thought of inefficient. The second analytical model was developed by reinterpretation by reinterpretation of the calculating process of the economic production quantity model. In this model we obtained two relationships, one of which is the relationship between optimal number of set-ups for the ith item and optimal total number of set-ups, the other is the relationship between optimal average inventory investment for the ith item and optimal total average inventory investment. From these relationships we can determine how much average inventory investment per year would be required if a rational policy based on m No set-ups per year for m products were followed and, alternatively, how many set-ups per year would be required if a rational policy were followed which required an established total average inventory inventory investment. We also learned the relationship between the number of set-ups and the average inventory investment takes the form of a hyperbola. But, there is no reason to say that the first analytical model is superior to the second analytical model. It can be said that the first model is useful for a basic production schedule. On the other hand, the second model is efficient to get an improved production schedule, in a sense of reducing the total cost. Another merit of the second model is that, unlike the first model where we have to know all the inventory costs for each product, we can obtain an improved production schedule with unknown inventory costs. The application of these quantitative analytical models to PoHang can-manufacturing plants shows this point.int.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1990.04a
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• pp.222-244
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• 1990

A multi-echelon structure of manufacturing and distribution system in considered, where the raw materials are transformed into a finished good through a number to manufacturing echelons and it is distributed to the lower echelons(retailers, or customers). The raw material, work-in-process, finished good inventory and the distribution costs are unified into one model. The objective is to determine the ordering policy of raw materials, manufacturing lot size, the number of sub-batch and the distribution policy of the finished good which minimize the annual total system cost. A computer program for a heuristic search technique is developed, by which a numerical example is examined.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.36
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• pp.93-103
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• 1995

This paper des with an economic production quantity model with partial backorders for the situation in which production lead time is deterministic and demand during lead time follows a continuous distribution. In the model, an objective function is formulated In minimize an average annual inventory cost. And then the procedure of iterative solution method for the model is developed to find both production reorder point and production quantity. Finally, sensitivity analysis for various partial backorder ratios and standard deviations of demand during production lead time are presented.

• Journal of Korean Institute of Industrial Engineers
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• v.15 no.1
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• pp.17-21
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• 1989

The problem to determine Economic Order Quantity(EOQ) occurs when price discounts or uncharged additions are offered for the purchase in the unit of package. It is found that the annual inventory cost needs to be evaluated for at most three alternative order sizes to find EOQ, which is easier than the case of all-unit or incremental quantity discount. Numerical examples are presented.

• Journal of Climate Change Research
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• v.9 no.4
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• pp.385-398
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• 2018

Although the importance of developing reliable and systematic GHG inventory has increased, the GIS/RS-based national scale LULUCF (Land Use, Land-Use Change and Forestry) sector analysis is insufficient in the context of the Paris Agreement. In this study, the change in $CO_2$ storage of forest land due to land use change is estimated using two GIS/RS methodologies, Sampling and Wall-to-Wall methods, from 2000 to 2010. Particularly, various imagery with sampling data and land cover maps are used for Sampling and Wall-to-Wall methods, respectively. This land use matrix of these methodologies and the national cadastral statistics are classified by six land-use categories (Forest land, Cropland, Grassland, Wetlands, Settlements, and Other land). The difference of area between the result of Sampling methods and the cadastral statistics decreases as the sample plot distance decreases. However, the difference is not significant under a 2 km sample plot. In the 2000s, the Wall-to-Wall method showed similar results to sampling under a 2 km distance except for the Settlement category. With the Wall-to-Wall method, $CO_2$ storage is higher than that of the Sampling method. Accordingly, the Wall-to-Wall method would be more advantageous than the Sampling method in the presence of sufficient spatial data for GHG inventory assessment. These results can contribute to establish an annual report system of national greenhouse gas inventory in the LULUCF sector.

• Safety and Health at Work
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• v.9 no.1
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• pp.101-108
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• 2018

Background: Work and work environment have a critical influence on adolescent workers' health. They are subjected to more risks than adults. The aim of this study is to examine psychological health outcomes in adolescent workers in the areas of depression, somatization, anxiety, hostility, and negative self-concept, and to investigate any related factors. Methods: This is a descriptive and cross-sectional study. Research samples were collected from adolescent workers between 15 and 18 years old attending a 1-day mandatory education course at vocational training centers, working 5 days per week in small enterprises. Data were collected using the following instruments: Brief Symptom Inventory, Multidimensional Scale of Perceived Social Support, and Descriptive Characteristics of Children's Assessment Form. Results: The investigation covers 837 young workers, of whom 675 were males and 162 were females. The majority of the families had low incomes (68.1%). Overall, 33.5% of the adolescents had been hospitalized because of health problems. Their average weekly working hours were $78.1{\pm}10.7$. Almost 50% of adolescent workers scored above the mean average in the Brief Symptom Inventory, indicating serious pschological health symptoms. Those who scored high for hostility, depression, negative self-concept, anxiety, and somatization were between 45.4% and 48.9% of the sample. Logistic regression analysis was conducted to determine the underlying factors: a perception of "feeling very bad" health conditions was 2.07-fold whereas the rate of "no annual leave" was 0.73-fold, and both were found to be effective on psychological problems. Conclusion: In this study, it seems likely that psychological health problems are the result of multiple adverse factors including working conditions, annual leave, and health considerations.

• Journal of Korean Society for Atmospheric Environment
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• v.30 no.6
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• pp.538-544
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• 2014

A traditional fireplace has been used, but not much, for heating and cooking in rural area, Korea. Traditional fireplace as one type of biomass burnings is also emitting various air pollutants. Air pollutants emission from traditional fireplace was estimated in this study. There are two types of traditional fireplace, one for combined heating and cooking, the other one for cooking only. Types of fuels mostly used in traditional fireplace were wood, agricultural residue, solid waste. Activity levels such as fuel types, amount of fuel loading, and temporal variation were investigated by field survey over Korea. Estimated annual emissions from traditional fireplace were CO 6,335.0, NOx 555.0, SOx 9.6, VOC 1,771.7, TSP 181.4, $PM_{10}$ 119.9, $PM_{2.5}$ 96.2, $NH_3$ 1.4 ton/yr respectively. When emissions compared with the national emission inventory (CAPSS: Clean Air Policy Support System) of 2010 year, CO and $PM_{10}$ occupy 0.8% and 0.1% of total national emission, respectively.

• Journal of Environmental Science International
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• v.23 no.9
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• pp.1643-1654
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• 2014

The university is one of the main energy consumption facilities and thereby releases a large amount of greenhouse gas (GHG). Accordingly, efforts for reducing energy consumption and GHG have been established in many local as well as international universities. However, it has been limited to energy consumption and GHG, and has not included air pollution (AP). Therefore, we estimated GHG and AP integrated emissions from the energy consumed by Seoul National University of Science and Technology during the years between 2010 and 2012. In addition, the effect of alternative energy use scenario was analysed. We estimated GHG using IPCC guideline and Guidelines for Local Government Greenhouse Inventories, and AP using APEMEP/EEA Emission Inventory Guidebook 2013 and Air Pollutants Calculation Manual. The estimated annual average GHG emission was $11,420tonCO_{2eq}$, of which 27% was direct emissions from fuel combustion sectors, including stationary and mobile source, and the remaining 73% was indirect emissions from purchased electricity and purchased water supply. The estimated annual average AP emission was 7,757 kgAP, of which the total amount was from direct emissions only. The annual GHG emissions from city gas and purchased electricity usage per unit area ($m^2$) of the university buildings were estimated as $15.4kgCO_{2eq}/m^2$ and $42.4tonCO_{2eq}/m^2$ and those per person enrolled in the university were $210kgCO_{2eq}$/capita and $577kgCO_{2eq}$/capita. Alternative energy use scenarios revealed that the use of all alternative energy sources including solar energy, electric car and rain water reuse applicable to the university could reduce as much as 9.4% of the annual GHG and 34% of AP integrated emissions, saving approximately 400 million won per year, corresponding to 14% of the university energy budget.

• Journal of Climate Change Research
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• v.7 no.4
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• pp.383-390
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• 2016

According to the "Framework Act on Low Carbon, Green Growth", publication of annual national greenhouse gas (GHG) inventory report is mandatory. This annual GHG inventory report is used as basal data for GHG mitigation strategies. In the livestock sector, GHG emission trends from year 1990 to 2013 were estimated based on the 1996 IPCC guidelines with the Tier 1 methodology. GHG emissions from the livestock sector in 2013 were 9.9 million tons $CO_2-eq$., where emissions from enteric fermentation were 4.4 million tons $CO_2-eq$, increased by 47.4% over 1990 mainly due to the increase in non-dairy cattle population. On the other hand, GHG emissions from livestock manure in 2013 were 5.5 million tons $CO_2-eq$, increased by 75.5% over 1990 mainly due to the increase in non-dairy cattle, swine and poultry populations. Additional research is required to develop country-specific emission factors to estimate GHG emissions precisely from livestock in South Korea.