• Korea Real Estate Review
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• v.28 no.1
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• pp.105-114
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• 2018

According to Statistics Korea, South Korea has entered the realm of the "aging society" with the rapid development of the country's population. Researchers anticipate that the extremely high (73%) ratio of real estate property to total assets for mid-age to aged households in South Korea that do not have a fixed income may cause serious problems in the future. For example, the real estate market in South Korea may be bombarded with properties listed for sale, causing the average property price to drop due to the abundant supply. Although this prediction may be reasonable, this concept has excluded the idea of pension (which is crucial as it can be considered a consistent and fixed income) due to the limited amount of available data thereon; as such, it is important to include this factor to improve the pertinent research. Thus, this research was conducted using the data from the $3^{rd}$ and $5^{th}$ Korea Retirement and Income Study. For the study results, it was found that variables such as net asset, gender, education, and number of family members have the same impact as that found in the previous studies. To extend from here, two new factors were introduced: the existence of pensions and the amount of pension received by a household. From there, it was found that the existence of a consistent and fixed income such as a pension has led to an increase in housing consumption, the area of interest of the authors.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.7
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• pp.915-929
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• 2023

Improvements in people's quality of life, diversification of leisure activities, and changes in population structure have led to an increase in the demand for tourism and an expansion of the diversification of tourism activities. In particular, for coastal cities where land and marine tourism elements coexist, various factors influence their tourism demands. Tourism requires the construction of infrastructure and content development according to the demand at the tourist destination. This study aims to improve the prediction accuracy and explore influencing factors through time series analysis of tourism scale using agent-based data. Basic local governments in the Busan area were examined, and the data used were the number of tourists and the amount of tourism consumption on a monthly basis. The univariate time series analysis, which is a deterministic model, was used along with the SARIMAX analysis to identify the influencing factor. The tourism consumption propensity, focusing on the consumption amount according to business types and the amount of mentions on SNS, was set as the influencing factor. The difference in accuracy (RMSE standard) between the time series models that did and did not consider COVID-19 was found to be very wide, ranging from 1.8 times to 32.7 times by region. Additionally, considering the influencing factor, the tourism consumption business type and SNS trends were found to significantly impact the number of tourists and the amount of tourism consumption. Therefore, to predict future demand, external influences as well as the tourists' consumption tendencies and interests in terms of local tourism must be considered. This study aimed to predict future tourism demand in a coastal city such as Busan and identify factors affecting tourism scale, thereby contributing to policy decision-making to prepare tourism demand in consideration of government tourism policies and tourism trends.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.11a
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• pp.61-70
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• 2004

This paper treats optimal route assessment system at seaway based on weather forecasting and wave measurement through observation. Since early times. captain & officer have been sailing to select the optimum route considering the weather ana ship status condition empirically. However. it is rare to find digitalized onboard route support system whereas weather fax or wave and swell chart are utilized for the officer. based on officer's experience. In this paper, optimal route assessment system which is composed of voyage efficiency and safety component is introduced. Optimum route minimized ETA (estimated time of arrival) ana fuel consumption is evaluated for efficient voyage considering speed loss and power increase based on wave added resistance of ship. In the view point of safety, seakeeping prediction is performed based on 3 dimensional panel method. Basically. the weather forecast is assumed to be prepared previously in order to operate this system.

• Journal of Navigation and Port Research
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• v.28 no.10 s.96
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• pp.833-841
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• 2004

This paper treats optimal route assessment system at seaway based on weather forecasting and wave measurement through observation Since early times, captain & officer have been sailing to select the optimum route considering the weather and ship status condition empirically. However, it is rare to find digitalized onboard route support system whereas weather fax or wave and swell chart are utilized for the officer, based on officer's experience. In this paper, optimal route assessment system which is composed of voyage efficiency and safety component is introduced. Optimum route minimized ETA(estimated time of arrival) and fuel consumption is evaluated for efficient voyage considering speed loss and power increase based on wave added resistance of ship. In the view point of safety, seakeeping prediction is performed based on 3 dimensional panel method. Basically, the weather forecast is assumed to be prepared previously in order to operate this system.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.7
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• pp.629-634
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• 2017

In the case of the UHP (Ultra high performance) tire that the demand has increased rapidly, compared with the commonly used tire, severe deformation has been observed because of the low aspect ratio. When repeated deformations are applied to the sidewall rubber, accumulated fatigue damage may cause fatigue failure. Thus, the evaluation of the durability of the tire sidewall rubber has become a very important issue to prevent accidents that occur while the vehicle is running. However, the research and design criteria for the durability performance of the tire sidewall rubber hardly exist. In this study, we suggest a lifetime prediction formula using strain energy density obtained by performing tensile tests and fatigue tests on two different kinds of the tire sidewall compounds. Additionally, the applicability of our findings for low fuel consumption tires was reviewed by converting the fatigue life of the sidewall rubber into the expected mileage of the tire.

• Journal of the Korea Society of Computer and Information
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• v.16 no.11
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• pp.245-253
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• 2011

Due to the imprudent spending of the fossil fuels, the environment was contaminated seriously and the exhaustion problems of the fossil fuels loomed large. Therefore people become taking a great interest in alternative energy resources which can solve problems of fossil fuels. The wind power energy is one of the most interested energy in the new and renewable energy. However, the plants of wind power energy and the traditional power plants should be balanced between the power generation and the power consumption. Therefore, we need analysis and prediction to generate power efficiently using wind energy. In this paper, we have performed a research to predict power generation patterns using the wind power data. Prediction approaches of datamining area can be used for building a prediction model. The research steps are as follows: 1) we performed preprocessing to handle the missing values and anomalous data. And we extracted the characteristic vector data. 2) The representative patterns were found by the MIA(Mean Index Adequacy) measure and the SOM(Self-Organizing Feature Map) clustering approach using the normalized dataset. We assigned the class labels to each data. 3) We built a new predicting model about the wind power generation with classification approach. In this experiment, we built a forecasting model to predict wind power generation patterns using the decision tree.

• Journal of IKEEE
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• v.25 no.2
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• pp.388-398
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• 2021

This paper proposes a particle swarm optimization (PSO)-based peak shaving scheme using energy storage system (ESS) for electricity tariff reduction. The proposed scheme compares the actual load with the estimated load consumption, calculates the additional output power that the ESS needs to discharge additionally to reduce peak load, and adds the input. In addition, in order to compensate for the additional power, the process of allocating power to the determined point is performed, and an optimization that minimizes the average of the load expected at the active power allocations using PSO so that the allocated value does not affect the peak load. To investigated the performance of the proposed scheme, case study of small and large load prediction errors was conducted by reflecting actual load data and load prediction algorithm. As a result, when the proposed scheme is performed with the ESS charge and discharge control to reduce electricity tariff, even when the load prediction error is large, the peak load is successfully reduced, and the peak load reduction effect of 17.8% and electricity tariff reduction effect of 6.02% is shown.

• Journal of the Korean Society of Industry Convergence
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• v.7 no.3
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• pp.233-240
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• 2004

This paper presents a feasibility study of a fresh air load reduction system by using an underground double floor space The system was introduced into a real building and was examined by the field measurement Judging from the measurements during three years(1999~2001), the state of the system operation was very stable through this period and it was clear that the system contributes to reduction of energy consumption for air-conditioning. Futhermore, a simulation model used the simple heat diffusion equation Was developed to simulate its thermal characteristics and performances The simulations resulted m air temperature in good agreement with the measurements. Also, from the result of numerical analysis, It is clear that the amount of heat supply by using this system is more than the amount of energy loss to the room above it. Therefore, it is concluded that this systems is very useful and the proposed numerical model can be used for the prediction of system thermal performance.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2283-2286
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• 2003

This paper presents conservation of electrical energy in building with harmonics analysis and compensation which occur in electrical system. We use load controlling and management system in order to adjust load factor of system.The maximum demand limiting and controlling are used ,then the system can acquire the prediction and compare it to the maximum demand set point.The electrical signal analysis based on FFT technique. The harmonics are compensated by using harmonic filters.This system consists computer which works as controller, processor , analysis and database unit together with digital power meter in form of multidrop network through serial communication via RS-485.The load control system uses PLC to control load via serial communication RS-485. The A/D converter is used for sampling the electrical signals via parallel port of computer.The harmonic filters are controlled by a computer.The data of measurement such as voltage, current, power, power factor, total harmonic distortion, energy, etc., can be saved as database and analysis. The load factor is adjusted by limiting and controlling maximum demand. The load factor adjustment can reduce the cost of electric consumption and energy generation together with harmonics compensation in order to increase high efficiency of electrical system.

• International Journal of Aeronautical and Space Sciences
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• v.16 no.2
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• pp.311-324
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• 2015

This study presents computational analyses for low-drag aerodynamic design that are applied to modify a long-endurance UAV. EAV-2 is a test-bed for a hybrid electric power system (fuel cell and solar cell) that was developed by the Korean Aerospace Research Institute (KARI) for use in future long-endurance UAVs. The computational investigation focuses on designing a wing with a reduced drag since this is the main contributor of the aerodynamic drag. The airfoil and wing aspect ratio of the least drag are defined, the fuselage configuration is modified, and raked wingtips are implemented to further reduce the profile and induced drag of EAV-2. The results indicate that the total drag was reduced by 54% relative to EAV-1, which was a small-sized version that was previously developed. In addition, static stabilities can be achieved in the longitudinal and lateral-directional by this low-drag configuration. A long-endurance flight test of 22 hours proves that the low-drag design for EAV-2 is effective and that the average power consumption is lower than the objective cruise powerof 200 Watts.