• Journal of the Economic Geographical Society of Korea
• /
• v.25 no.4
• /
• pp.484-498
• /
• 2022

The purpose of this study is to analyze the location, distribution and its change of photovoltaic power generation in the scale of municipality(Si-Gun-Gu). First the distribution of photovoltaic power generation was analyzed in 2020, and second, from 2017 to 2021, we tracked the increase in capacity of power generation facilities in each Si-Gun-Gu. As a result, the distribution and increase of photovoltaic power generation were concentrated in some regions and the unequal distribution of photovoltaic power generation has been identified through Gini coefficient.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.46 no.8
• /
• pp.50-58
• /
• 2009

Fourth generation mobile communication network have the technology of extensive form include basic service technology and it has been developed from the radio access technology and network topology. Not only fourth generation mobile communication network have basically done new highspeed radio access technology which is suitable to high and low speed environment of transfer, but also it is possible that they have been made for freely vertical handover. ETRI also has made fourth generation mobile communication network which is WiNGS(Wireless Initiative for Next Generation Service) satisfied that demand. This paper is made by lossless handover method through the local retransmission ARQ agent that is one of the main technology of fourth generation mobile communication network. Lossless handover method through local retransmission ARQ agent has been basically made by WiNGS and it was better than original local retransmission of layer by simulation.

• Journal of Sericultural and Entomological Science
• /
• v.23 no.1
• /
• pp.32-37
• /
• 1981

It is necessary to improve new silkworm variety suitable for the artificial diet different from the mulberry leaves in physical and chemical natures. The silkworms fed on artificial diet show low productivity in general. So the effectiveness of selection for cocoon characters was studied when the silkworms were reared on the artificial diet for several generations. The results obtained are as fellows: 1. There is no correlation between the cocoon shell weight and the cocoon shell percentage in female cocoons of both Sa and Y strains but in male cocoons. 2. No correlation exists between the weight of a cocoon and a cocoon shell percentage of male cocoons in Sa strain. 3. There is a specific effect of the artificial diet on selection between Japanese and Chinese strains compared with the mulberry leave rearing. 4. The cocoon quality of first generation in artificial diet rearing was very inferier to that of previous generation in mulberry leave rearing in both Sa and Y strains, but the effect of selection rapidly increased in first and second generation.5. Very high mortality was noted in 4th generation to the degree of hardness for successive generation. 6. From 6th generation to 10th generation, the effectiveness of selection for cocoon characters increased continuously except the cocoon shell percteage.

• Journal of the Korea Society of Computer and Information
• /
• v.26 no.10
• /
• pp.27-35
• /
• 2021

Local search has been used to solve various combinatorial optimization problems. One of the most important factors in local search is the method of generating a neighbor solution. In this paper, we propose neighbor generation strategies of local search for permutation-based combinatorial optimization, and compare the performance of each strategies targeting the traveling salesman problem. In this paper, we propose a total of 10 neighbor generation strategies. Basically, we propose 4 new strategies such as Rotation in addition to the 4 strategies such as Swap which have been widely used in the past. In addition, there are Combined1 and Combined2, which are made by combining basic neighbor generation strategies. The experiment was performed by applying the basic local search, but changing only the neighbor generation strategy. As a result of the experiment, it was confirmed that the performance difference is large according to the neighbor generation strategy, and also confirmed that the performance of Combined2 is the best. In addition, it was confirmed that Combined2 shows better performance than the existing local search methods.

• 연구논문집
• /
• s.31
• /
• pp.45-51
• /
• 2001

One of emerging technologies under development in the advanced countries is considered as RDF(Refuse Derived Fuel) power generation, which could meet both the requirement of an alternative energy resource utilization and $CO_2$ reduction. This paper deals with the effect to the thermal effiency and CO2 reduction of RDF firing power generation. The statistical data of domestic MSW generation in last year in small and medium cities for evaluating the merits of the RDF power generation were used. The analysis for RDF power generation compared to the existing incinerator w/o(or w/) power generation shows around 20.6%(10.0%) up in the total thermal efficiency and 57.0%(31.4%) up in the $CO_2$ reduction respectively.

• Bulletin of the Korea Photovoltaic Society
• /
• v.4 no.2
• /
• pp.45-53
• /
• 2018

Natural gas demand for power generation continued to increase until 2013 due to the expansion of large-scale LNG power plants after the black-out of 2011. However, natural gas demand for power generation has decreased sharply due to the increase of nuclear power and coal power generation. But demand for power generation has increased again as energy policies have changed, such as reducing nuclear power and coal power plants, and abnormal high temperatures and cold waves have occurred. If the gas pipeline pressure can be properly maintained by predicting these fluctuations, it can contribute to enhancement of operation efficiency by minimizing the operation time of facilities required for production and supply. In this study, we have developed a regression model with daily power demand and base power generation capacity as explanatory variables considering characteristics by day of week. The model was constructed using data from January 2013 to December 2016, and it was confirmed that the error rate was 4.12% and the error rate in the 90th percentile was below 8.85%.

• Journal of Electrical Engineering and Technology
• /
• v.12 no.4
• /
• pp.1386-1396
• /
• 2017

In this paper, a new approach is proposed to select the optimal sitting and sizing of distributed solar photovoltaic generation (SPVG) in a radial electrical distribution systems (EDS) considering load/generation uncertainties. Here, distributed generations (DGs) allocation problem is modeled as optimization problem with network loss based objective function under various equality and inequality constrains in an uncertain environment. A boundary power flow is utilized to address the uncertainties in load/generation forecasts. This approach facilitates the consideration of random uncertainties in forecast having no statistical history. Uncertain solar irradiance is modeled by beta distribution function (BDF). The resulted optimization problem is solved by a new Dynamic Harmony Search Algorithm (DHSA). Dynamic band width (DBW) based DHSA is proposed to enhance the search space and dynamically adjust the exploitation near the optimal solution. Proposed approach is demonstrated for two standard IEEE radial distribution systems under different scenarios.

• Journal of the Korea Computer Industry Society
• /
• v.4 no.4
• /
• pp.433-442
• /
• 2003

The performance of communication systems should be tested against a set of requirements. To this end, noise generation systems are used to generate noise signals with specified characteristics. In recent study, noise generation system using DCT outperforms the conventional noise generation system when a noise model requires complicated PSD(Power Spectral Density) specifications. In this paper low area/power structures of non-DCT block in DCT-based noise generation system are proposed. Simulation results show that the low area structure results in area reduction by 61-64% and the low power structure achieves power reduction by 88-89% except DCT blocks.

• Current Photovoltaic Research
• /
• v.4 no.2
• /
• pp.80-86
• /
• 2016

Since the last five years it has become a lot of solar power plants installed. However, by installing the large-scale solar power station it is not easy to predict the actual generation years. Because there are a variety of factors, such as changes daily solar radiation, temperature and humidity. If the power output can be measured accurately it predicts profits also we can measure efficiency for solar power plants precisely. Therefore, Prediction of power generation is forecast to be a useful research field. In this study, out discovering the factors that can improve the accuracy of the prediction of the photovoltaic power generation presents the means to apply them to the power generation amount prediction.

• Journal of Korean Society for Atmospheric Environment
• /
• v.16 no.1
• /
• pp.37-47
• /
• 2000

The Urban thermal environment is influenced and modified in many ways. One modification is brought by the anthropogenic heat generation emitted from the combustion processes and the use of energy such as industrial, domestic and traffic procedure. The anthropogenic heat generation affect an the increase of urban temperature, the well-known urban heat islands. The study on the urban thermal environment needs a great deal of the statistic data about the inner-structure of urban, the contribution of different constructions and the traffic amount on urban thermal environment in finite region. In order to overtake a quantitative analysis of effect of the anthropogenic heat, a distribution map of the urban anthropogenic heat was made using hte data of the energy consumption used at the several constructions and traffic amount of vehicles in Pusan Metropolitan. Annual mean heat flux over the 4$\textrm{km}^2$ urbanized area in Pusan is 41.5W/$m^2$, ranging from 31.4W/$m^2$ in summertime to 59.5W/$m^2$ in wintertime and maximum diurnal anthropogenic heat generation is corresponding to 10% of irradiance during summertime.