• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.50 no.1
• /
• pp.67-74
• /
• 2014

Most of steam power plants in Korea are using the method of heating the feed water whenever the ambient temperature around the power plant area below $5^{\circ}C$ to prevent freezing water flowing in the pipe in winter time. But this kind of heat supplying system is not useful to save energy. If we take the method that the temperature of the each pipe is controled by direct measure of temperature by attaching sensor on the outside surface of the feed water tubes, then we can expect that a plenty of energy can be saved. In this study, the computer simulation is used to compare the energy consumption loads of both systems. Energy saving rate is calculated for the location of Incheon area in winter season. Four convection heat transfer coefficients for the ambient air and three initial flowing water temperature inside the tube were used. The result shows that the temperature control system using sensor represents more than 95% of energy saving rate in Incheon area. Even in the severe January weather condition, the energy saving rate is almost 75% in two days basis and even 83% in one day basis.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.7 no.8
• /
• pp.1805-1824
• /
• 2013

Recently, the use of wireless body area networks (WBAN) has been increasing rapidly in medical healthcare applications. WBANs consist of smart nodes that can be used to sense and transmit vital data such as heart rate, temperature and ECG from a human body to a medical centre. WBANs depend on limited resources such as energy and bandwidth. In order to utilise these resources efficiently, a very well organized medium access control (MAC) protocol must be considered. In this paper, a new, adaptive and energy-efficient MAC protocol, entitled isMAC, is proposed for WBANs. The proposed MAC is based on multi-channel communication and aims to prolong the network lifetime by effectively employing (i) a collision prevention mechanism, (ii) a coordinator node (WCN) selection algorithm and (iii) a transmission power adjustment approach. The isMAC protocol has been developed and modelled, by using OPNET Modeler simulation software. It is based on a networking scenario that requires especially high data rates such as ECG, for performance evaluation purposes. Packet delay, network throughput and energy consumption have been chosen as performance metrics. The comparison between the simulation results of isMAC and classical IEEE 802.15.4 (ZigBee) protocol shows that isMAC significantly outperforms IEEE 802.15.4 in terms of packet delay, throughput and energy consumption.

• Journal of Korea Society of Industrial Information Systems
• /
• v.19 no.6
• /
• pp.1-6
• /
• 2014

The delay-insensitive Null Convention Logic (NCL) asynchronous design as one of innovative asynchronous logic design methodologies has many advantages of inherent robustness, power consumption, and easy design reuses. However, transistor-level structures of conventional NCL gate cells have weakness of low speed, high area overhead or high wire complexity. Therefore, this paper proposes a new high-speed NCL gate cells designed at transistor level for high-speed, low area overhead, and low wire complexity. The proposed NCL gate cells have been compared to the conventional NCL gates in terms of circuit delay, area and power consumption.

• KIEAE Journal
• /
• v.10 no.1
• /
• pp.57-64
• /
• 2010

Electric energy is indispensible of the development of the industrial and living sector. Among the energy sectors, the building area shares 20% of the produced electric power in Korea. As we plan to supply the apartment, we need to forecast the required amount of the electric energy and supply the infrastructure to apartment for the lighting, cooling. Nonetheless, it is not easy to forecast the required amount of the electric energy, considering the management aspect, building physical aspect and social-geographic aspect. In this paper, it studied the estimation model of the electric energy, reflecting the affecting variables such as total area, number of household, geography and so on. The estimation model is proposed in 3-types which explained in central heating, individual heating and district heating, and each type have two estimation model, reflecting the affecting variable and corelation between variables to eliminate the muticolinearity. The unit of electric energy consumption per area and year is similar in three heating type and the results are as follows; the central heating is $34.446kWh/yr{\cdot}m^2$, individual type is $35.756446kWh/yr{\cdot}m^2$ and district heating is $34.285446kWh/yr{\cdot}m^2$.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.7A
• /
• pp.669-677
• /
• 2011

Superframe in IEEE 802.15.4 Standard is subdivided into an active period and an inactive period to reduce energy consumption. But communication nodes use same data transmission range in an active period, thus communication nodes spend a lot of energy to send data another nodes. In this paper, we proposed reduce energy consumption algorithm that nodes use different transmission power. Cordinator split transmission area into four group and transmit becon message to nodes. Nodes adjust transmission power according to becon message and wates lowe energy than normal nodes. We proposed energy-efficient cross layer protocol that have different PAN (Personal Area Network) by four range group.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.05a
• /
• pp.483-485
• /
• 2010

A 200kS/s 10-bit successive approximation(SA) ADC with a rail-to-rail input range is proposed. The proposed SA ADC consists of DAC, comparator, and successive approximation register(SAR) logic. The folded-type capacitor DAC with the boosted NMOS switches is used to reduce the power consumption and chip area. Also, the time-domain comparator which uses a fully differential voltage-to-time converter improves the PSRR and CMRR. The SAR logic uses the flip-flop with a half valid window, it results in the reduction of the power consumption and chip area. The proposed SA ADC is designed by using a $0.18{\mu}m$ CMOS process with 1V supply.

• The Journal of Fisheries Business Administration
• /
• v.50 no.3
• /
• pp.17-29
• /
• 2019

This paper aims to find out the problems and improvement direction of quality control and hygiene management of fishery products in Korea. For this reason, we conducted a comparative analysis of quality control and hygiene management of fishing, landing and selling between Japan and Korea, taking mackerel as an example. Japan has established a systematic freshness management system from fishing to landing (production) areas and consumption areas. On the other hand, Korea is not fully lead-managed in the production area after fishing, and is distributed in a state where the quality of the product is deteriorated due to exposure to room temperature. Accordingly, a certain quality can not be secured at the final consumption stage, and sanitary problems occur. In order to improve the quality control and hygiene management of the fishery products, the following needs to be improved. First, we will improve the fishing level freshness management system. Second, we will improve the quality control and hygiene management of fish in the production area and wholesale stage. Third, we will promote the introduction of innovative sales and consignment sales systems at the production stage. Fourth, we will establish a consistent low temperature distribution system from the production area to the wholesale stage from a long-term perspective. Fifth, we will promote the development and education of manuals on fish quality and hygiene management.

• Journal of Korean Port Research
• /
• v.11 no.1
• /
• pp.13-28
• /
• 1997

Today the congestion problem is a problem for the most of the cities to solve. Especially, traffic congestion in the big cities is occurring regardless of the rush-hours. Because the transportation facilities secured in the big cities are very low, and the financial resources and sites for the expansion of new transportation facilities are also limited. Therefore the appropriate Transportation system Management(TSM) techniques which could improve the transportation system are absolutely required to solve the transportation problems instead of the expansion of the transportation facilities in the big cities. The purpose in this study was to review the travel characteristics on the Pretimed Signalized - Intersections under the study in Pusan area, construct the travel systems during the different time-periods based upon the travel characteristics reviewed, and finally suggest the optimal travel systems which could reduce the traffic delay and fuel consumption of the Pretimed Signalized - Intersections based upon the travel system constructed. Based upon the results, it could be concluded that the pretimed signal system based upon the on-peak periods should not be applied to all the different time-periods on the Pretimed Signalized - Intersections(PSI) to reduce traffic delay and fuel consumption, and increase the travel capacity on the intersections in Pusan area.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.58 no.3
• /
• pp.347-350
• /
• 2009

In this study, it was studied about the improved road light design for drivers and pedestrians using forward or reverse ray-tracing method. Many of conventional road lights are not suitable for drivers and pedestrians because it has some serious problems such as glare effect or randomicity of illuminated areas. It was oriented from customary design method which was pointed at simple target such as luminance or electrical power. But it was not truth any more that the high luminance or electrical power consumption mean more bright and good road light. We studied ray-tracing method for road light reflector design to get the several goals. It means that good road light has easy for drivers and pedestrians eyes and illuminating objects on the road clearly. So, we set the design targets such as uniformity on the road area per one road light, shading angles and continuous luminance uniformity on the long distance road. We designed ideal road light conditions using ray-tracing method. We set the height of drivers and pedestrians eyes and calculated design guideline to make above design targets. Then we designed road light reflector using reverse ray-tracing method. And we achieved same luminance on the road almost half power consumption because we reduced loss of light. We achieved ideal design guide as 75 degrees of shading angles and 0.5 of luminance uniformity on the road area. It is superior than conventional road light ability such as 0.35 of luminance uniformity of 400 watts power consumption lamp. Finally, we suggested reflector design for 250 watts power consumption CDM Iight source.

• Korean Journal of Human Ecology
• /
• v.20 no.3
• /
• pp.677-689
• /
• 2011

The principal objective of this study was to evaluate the consumption behavior and perceptions of environmentally-friendly agricultural products (EAPs) according to the lifestyles of housewives in the Jeonbuk area, Korea. Self-administered questionnaires were collected from 267 housewives. Frequency analysis, chi-square, one-way ANOVA, factor analysis, and cluster analysis were used to analyze the data. Three clusters were obtained from the cluster analysis of LOHAS and wellbeing-related lifestyle: Cluster 1 "LOHAS-pursuit group", Cluster 2 "wellbeing-progress group", Cluster 3 "Utility-pursuit group". Of the housewives who were of LOHAS-pursuit group, about 50% were over 40 years old and had a professional job with a high household income. They had a high level of understanding about EAPs and purchased the highest percentage of EAPs among the groups. The housewives who were of the wellbeing-progress group, over 83% were between the ages of 30 and 40. Their consumption behaviors were very similar with that of the LOHAS-pursuit group, but the household income was lower. Of the housewives who were of the utility-pursuit group, about 63% under 30 years old. Their household income and level of understanding about EAPs were the lowest among the groups. They less interest in EAPs in comparison with other groups. For housewives' to choose EAPs properly, information and consumer education on these products, according to their lifestyles is necessary.