• International Journal of High-Rise Buildings
• /
• v.8 no.2
• /
• pp.117-123
• /
• 2019

Tall buildings are prone to wind-induced vibrations due to their slenderness whereby peak structural accelerations may be higher than the recommended maximum value. The common countermeasure is the installation of a tuned mass damper (TMD) near the highest occupied floor. Due to the extremely large modal mass of tall buildings and because of the narrow to broad band type of wind excitation the TMD mass may become inacceptable large - in extreme cases up to 2000 metric tons. It is therefore a need to develop more efficient TMD concepts which provide the same damping to the building but with reduced mass. The adaptive TMD concept described in this paper represents a solution to this problem. Frequency and damping of the adaptive TMD are controlled in real-time by semi-active oil dampers according to the actual structural acceleration. The resulting enhanced TMD efficiency allows reducing its mass by up to 20% compared to the classical passive TMD. The adaptive TMD system is fully fail-safe thanks to a smart valve system of the semi-active oil dampers. In contrast to active TMD solutions the adaptive TMD is unconditionally stable and its power consumption on the order of 1 kW is negligible small as controllable oil dampers are semi-active devices. The adaptive TMD with reduced mass, stable behavior and lowest power consumption is therefore a preferable and cost saving damping tool for tall buildings.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.9
• /
• pp.1799-1807
• /
• 2016

In this paper, we propose the automatic demand response systems which reduce the electric power consumption for the period automatically distinct from the existing passive demand response that a subscriber directly controls the energy consumption. The proposed systems are based on SEP 2.0 and consist of the demand response management program, the demand response server, and the demand response client. The demand response program shows the current status of the electric power use to a subscriber and supports the function which the administrator enables to creates or cancels a demand response event. The demand response server transmits the demand response event received from the demand response management program to the demand response client through SEP 2.0 protocol, and it stores the metering data from the demand response client in a database. After extracting the data, such as the demand response the start time, the duration, the reduction level, the demand response client reduces the electric power consumption for the period.

• Journal of KIISE:Information Networking
• /
• v.35 no.1
• /
• pp.34-45
• /
• 2008

In dynamic wireless sensor networks where sources and sinks are moving or are created/died, control overheads for route establishment are increased and thus become one of the major factors for energy consumption. This study introduces prefetching and pruning for Directed Diffusion to remove redundant control messages. Prefetching collects path information for each event with "AnyEvent" in advance and gives quick responses without further flooding of requests. Pruning accumulates history information from previous requests and replies, and then stops forwarding a request towards where the event does not exist. Simulation results with ns show that it is possible to build implicit and soft infrastructures within a Directed Diffusion system through these active collection and passive accumulation and they improve energy consumption more as control overhead goes higher.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.26 no.1
• /
• pp.63-70
• /
• 2015

In this paper, a receiver has been developed in a $0.11-{\mu}m$ CMOS technology for 900 MHz RFID communication system applications. The receiver is composed of an envelope detector, a low-pass-filter, a comparator, D flip-flops, as well as an oscillator to provide the clock for digital blocks. The receiver is designed for low power consumption, which would be suitable for passive RFID tags. In this circuit, a digital data slicer was employed instead of the conventional analog data slicer in order to reduce the power consumption. The clock frequency is 1.68 MHz and the circuit operates with a power consumption as small as $5{\mu}W$. The chip size is $325{\mu}m{\times}290{\mu}m$ excluding the probing pads.

• Journal of Korean Institute of Architectural Sustainable Environment and Building Systems
• /
• v.12 no.6
• /
• pp.543-556
• /
• 2018

Zero energy building was attended for energy consumption minimization by the energy saving technology about building heating and cooling energy consumption and the renewable energy production facility. So the government has supported the zero energy building supply for decreasing green gas emissions. The study about inventory of zero energy building has many proceeding. That inventory need the information of material and equipment. So information of material and equipment about zero energy building must be included for the zero energy building realization. Actually the database of zero energy building inventory construction through the inventory established studies has difficult because the database need many information. In this study, author proposed the test methods and performance reference for upload at inventory. It was constructed to material - module - package. Also the author analyzed the construction of the technical package for zero energy building. The author separated performance category to the energy performance for energy analysis and other performance for confirmed the durability, stability and etc. This performance category proposed the table. The test methods of material and equipment in the passive package and active package proposed to the international standard and korea standard basically korea standard. Also the performance reference was proposed to korea legal standard and various standard by this study results. And the authors proposed the table of performance value, test methods, performance reference. By result of this study, the test methods and performance reference will be used the basic data for inventory of zero energy building.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.19 no.4
• /
• pp.39-52
• /
• 2023

This study analyzes the energy performance of a elderly care center building and the applicability of a ground source heat pump (GSHP) system through simulation approach. For this purpose, a building information modeling (BIM) program and an energy performance calculation program were used. The impact of the mechanical ventilation system on the energy requirements of the heating and cooling system and the indoor environment was also analyzed, focusing on the change in indoor carbon dioxide (CO₂) concentration, which is a representative indicator of the indoor environment (air quality). The simulation results showed that the target building exceeds Level 7 in terms of simulated primary energy consumption or actual energy consumption. In addition, it was analyzed that the target building could not maintain the indoor CO₂ concentration below the standard concentration by natural ventilation through window opening alone. Combining the GSHP system with the mechanical ventilation system (Case B and Case C) can further reduce the overall energy consumption by reducing the amount of outdoor air introduced by opening windows. The cost savings compared to the baseline case are estimated to be 67.3% for Case A, 63.7% for Case B, 65.5% for Case C, and 42.5% for Case D. It is necessary to analyze the impact of various renewable energy technologies and passive ones on the energy performance and indoor environment of elderly care centers.

• Journal of Korean Home Economics Education Association
• /
• v.30 no.2
• /
• pp.103-116
• /
• 2018

The purpose of the present study is to categorize collaborative consumption intention in high school students based on providing and using collaborative consumption behaviors, to compare and analyze the factors that predict these. Data gathered from 418 high school students through an online survey were used to conduct a descriptive statistics analysis, cluster analysis, and multinomial logistic regression. Firstly, collaborative consumer intentions were classified into four groups, including a proactive group with high providing behaviors and using behaviors, an active providing group, an active using group, and a passive group with low providing and using behaviors. Secondly, mass media, social benefits, enjoyment, community effect, and reputation were revealed as factors that increased the potential for inclusion in the active groups, and home education, mass media, enjoyment, and reputation were factors that increased the potential for inclusion in the active providing group. Enjoyment was revealed as the factor that increased the potential for inclusion in the active using group. The results of the present study show that the active utilization of consumer education and a systematic approach are required to revitalize collaborative consumption and proper settlement. Furthermore, a systematic establishment of school consumer education is needed for the balanced development of collaborative consumption. Also, an environmental system in which actual expected benefits can be experienced and realized in a diverse manner should be created to encourage consumers collaborate more actively.

• Proceedings of the KIPE Conference
• /
• 2011.11a
• /
• pp.44-45
• /
• 2011

Research on photovoltaic (PV) generation is taking a lot of attention due to its infinity and environment-friendliness with decrease of price per PV cell. While central inverters connect group of PV modules to utility grid in which maximum power point tracking (MPPT) for each module is difficult, micro inverter is attached on each module so that MPPT for individual modules can be easily achieved. Moreover, energy generation and consumption efficiency can be much improved by employing direct current (DC) distribution system. In this paper, a digitally controlled PV micro converter interfacing PV to DC distribution system is proposed. Boundary conduction mode (BCM) is utilized to achieve zero voltage switching (ZVS) of active switch and eliminate reverse recovery problem of passive switch. A 120W prototype boost PV micro converter is implemented to verify the feasibility and experimental results show higher than 98% efficiency at peak power and 97.29% of European efficiency.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.12 no.2
• /
• pp.829-842
• /
• 2018

Unmanned Aerial Vehicle (UAV) is diversely utilized in our lives such as daily hobbies, specialized video image taking and disaster prevention activities. New ways of UAV application have been explored recently such as UAV-based delivery. However, most UAV systems are being utilized in a passive form such as real-time video image monitoring, filmed image ground analysis and storage. For more proactive UAV utilization, there should be higher-performance UAV and large-capacity memory than those presently utilized. Against this backdrop, this study described the general matters on proactive software platform and high-performance UAV hardware for real-time target tracking; implemented research on its design and implementation, and described its implementation method. Moreover, in its established platform, this study measured and analyzed the core-specific CPU consumption.

• Journal of Preventive Medicine and Public Health
• /
• v.30 no.1 s.56
• /
• pp.181-193
• /
• 1997

The purpose of this study was to identify population subgroups with similar patterns of diet quality, physical activity, alcohol consumption and cigarette smoking of Korean. The cluster analysis was conducted using the data from Korea National Health Survey(KNHS) in 1995, which consisted of 5,805 persons. We identified six health behavior typologies : 32.9% of the sample had a good diet but sedentary activity level(good diet lifestyle), 7.2% had high activity level but less diet quality(fitness lifestyle). Individuals in the passive lifestyle cluster(39.1%) had no active health promoting activities but tended to avoid risk taking health behavior such as cigarette smoking and alcohol drinking. 1.1% of the sample were in a drinking cluster, 17.2% in a smoking cluster and 2.5% had a hedonic lifestyle characterized by heavy drinking and smoking. The other characteristics of these lifestyle clusters could be presented by demographic and socioeconomic factors.