• 한국통신학회논문지
• /
• 제21권12호
• /
• pp.3154-3164
• /
• 1996

A major concern in a cellular mobile communication system is how to efficiently utilize the limited amount of frequencies. Various channel assignment methods and traffic sharing schemes have been proposed to improve system performance. However, these approaches suffer from complicated software and hardware requirements due to increased amount of traffic control In this paper, we propose a new method for improving system performance by controlling the powers of the set-up and voice channels of each cell site. We first show that the average number of blocked calls in a system is minimized when the traffic reates are made identical for all cell sites in a system. This result, together with the relationship between the channel powers and the service area, is used to determine the appropriate channel powers of each cell site. We also determine the upper limit on the channel power of each cell site considering co-channel interference and numerically show that the proposed method is effective in reducing the number of blocked calls without an excessive increase in the amount of system control.

• 한국컴퓨터정보학회논문지
• /
• 제22권5호
• /
• pp.81-88
• /
• 2017

Solar-powered wireless sensor nodes can use extra energy to obtain additional data to increase the precision. However, if the amount of data sensed is increased indiscriminately, the overhead of relay nodes may increase, and their energy may be exhausted. In this paper, we introduce a sensing and compression rate selection scheme to increase the amount of data obtained while preventing energy exhaustion. In this scheme, the neighbor nodes of the sink node determine the limit of data to be transmitted according to the allocated energy and their descendant nodes, and the other nodes select a compression algorithm appropriate to the allocated energy and the limitation of data to be transmitted. A simulation result verifies that the proposed scheme gathers more data with a lower number of blackout nodes than other schemes. We also found that it adapts better to changes in node density and the amount of energy harvested.

• 한국방송∙미디어공학회:학술대회논문집
• /
• 한국방송공학회 2009년도 IWAIT
• /
• pp.351-354
• /
• 2009

Distributed video coding (DVC) is a new coding paradigm that enables to exploit the statistics among sources only in decoder and to achieve extremely low complex video encoding without any loss of coding efficiency. Wyner-Ziv coding, a particular implementation of DVC, reconstructs video by correcting noise on side information using channel code. Since a good quality of side information brings less noise to be removed by the channel code, generation of good side information is very important for the overall coding efficiency. However, if there are complex motions among frames, it is very hard to generate a good quality of side information without any information of original frame. In this paper, we propose a method to enhance the quality of the side information using small amount of additional information of original frame in the form of hash. By decoder's informing encoder where the hash has to be transmitted, side information can be improved enormously with only small amount of hash data. Therefore, the proposed method gains considerable coding efficiency. Results of our experiment have verified average PSNR gain up to 1 dB, when compared to the well-known DVC codec, known as DISCOVER codec.

• 경영과정보연구
• /
• 제12권
• /
• pp.181-201
• /
• 2003

An employee employment of Enterprise must consider efficiency, balance attribute and effectiveness as important variable. but Our country's Enterprise reduce the personnel without basic guide line about employee employment. because Our country's Enterprise thinks of personnel expenses or sales amount decrease as important variable. Therefore, Research background sets out that there is no basic guideline for employment management one of the most important elements in Enterprise administration. and I examined employment control's concept and concept about softness of labor market in theoretical background setting. Also, was abreast of employment control effect, case study and literature research about employment control's basis. Finally, In fluctuation change of Enterprise's employee number, I examined which relation is formed in comparison with sales amount, net profit and the employee number of individual Enterprise using investment analysis material of Stock Company focused on Enterprise that stock is listed on the stock exchange.

• 한국컴퓨터정보학회논문지
• /
• 제24권4호
• /
• pp.11-18
• /
• 2019

Previous mutual authentication schemes operate on the basis of validated cryptographic functions and hash functions, but these functions require a certain amount of memory capacity. However, since ultra-lightweight IoT devices have a very small amount of memory capacity, these functions can not be applied. In this paper, we first propose a text steganography communication scheme suitable for ultra-lightweight IoT devices with limited resources, and then propose a mutual authentication scheme based on the text steganography communication. The proposed scheme performs mutual authentication and integrity verification using very small amount of memory. For evaluation, we implemented the proposed scheme on Arduino boards and confirmed that the proposed scheme performs well the mutual authentication and the integrity verification functions.

• 통상정보연구
• /
• 제7권3호
• /
• pp.247-268
• /
• 2005

In this study, I analysed the influence of the Korean Officially Supported Export Credit System upon Improvement upon Korean Export, investigated Korean Officially Supported Export Credit System focussing on the Short-term Export Loan System & Medium and Long-term Export Loan System in Korea Eximbank and sought for the measures overcoming problems therewith. In my research I started from a basic model analyzing Short-term Export Loan & Medium and Long-term Export Loan using added several variables that have effect on export such export relative price, world income and the amount of post-shipment credit bank guarantee. As a result, amount of Short-term Export Loan & Medium and Long-term Export Loan, world income and export relative price showed expected responses and Short-term Export Loan was significant. In case of amount of Short-term Export Loan System was statistical significance.

• 통상정보연구
• /
• 제8권1호
• /
• pp.259-281
• /
• 2006

In this study, I analysed the Direction of Progress for the Korean Export Insurance upon Export Support for Its Small-Middle Company, investigated Korean Export Insurance focussing on the Export Support for Its Small-Middle Company since Korea Export Insurance Coporation(KEIC)'s establishment and sought for the measures overcoming problems therewith. In my research I started from a basic model analyzing the Korean Export Insurance for Its Small-Middle Company using added several variables that have effect on such export relative price, world income and the amount of the Korean Export Insurance for Its Small-Middle Company. As a result, amount of the Korean Export Insurance for Its Small-Middle Company, world income and export relative price showed expected responses and were significant. Also world income showed expected responses but was not significant. In case of amount of the Korean Export Insurance for Its Small-Middle Company was statistical significance.

• 한국디지털건축인테리어학회논문집
• /
• 제10권3호
• /
• pp.19-28
• /
• 2010

The construction projects are recently having changes in their magnitude and complexity. Therefore, the amount of information created and managed by participants over project phases is enormous and this may cause difficulties in consistent and integrated data management. Because of the change in construction projects, there is a need to apply more logical and systematic ways to deal integrated data management. For the solution to this, BIM(Building Information Modeling), a new paradigm for integrated management of the information over project life-cycle, has been seriously considered. Also, the Korean Public Procurement Service announced that project over 50 billion Korean Won should introduce BIM into procurement starting from 2012. However, the studies and development have lack on studies of applying BIM and managing the data made using BIM in pre-design and maintenance stage. In pre-design stage, the concept of schematic design model is made to support for making major decisions concerning the size, shape and cost of the project. To decide the cost for the building in this stage by making use of BIM, estimating the amount of building materials used for constructing should be preceded. In this study, the pre-design BIM is explained to gain a better understanding of its process, since this paper focused on space programming stage. Finally, the paper suggests the concept process of estimating the amount of materials in building interior finishing from selecting the type for the elements of each space made to support the client for making decisions in space programming stage based on pre-design BIM.

• 한국농업기계학회:학술대회논문집
• /
• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.II
• /
• pp.236-245
• /
• 2000

The feasibility of precision farming for small sized fields was studied by determining fertilizing amount of nitrogenous and calcareous to a cite specific region. A detailed soil survey at three experimental fields of 672㎡, 300㎡ and 140㎡ revealed a considerable spatial variation of the pH and organic matter(OM) levels. Soil organic matter was measured using Walkley-Black method and soil pH was measured with a pH sensor. Soil sample was obtained by Grid Node Sampling Method. The soil sampling depth was 10 - 20 cm from the soil surface. To display soil nutrient variation, a soil map was made using Geographic Information System (GIS) software. In soil mapping, soil data between nodes was interpolated using Inverse Distance Weighting (IDW) method. The variation was about 1 - 1.8 in pH value and 1.4 -7 % in OM content. Fertilizing Amount of nitrogenous and calcareous was determined by the fertilizing equation which was proposed by National Institute of Agricultural Science and Technology.(NIAST). The variation of fertilizing amount was about 3 - 11 kg/10a in nitrogenous and 70 - 140 kg/10a in calcareous. The results showed a feasibility of precision fertilizing for small size fields.

• 디지털산업정보학회논문지
• /
• 제13권3호
• /
• pp.27-33
• /
• 2017

In this paper presents the MPPT tracking algorithm using angle control of flexible PV in BIPV. The proposed algorithm is based on MPPT tracking algorithm for curtain wall using flexible PV. It is an algorithm to find optimal power generation condition by controlling the angle of flexible PV using the air layer of window. The angle of flexible PV tests the power generation by separating the center of flexible PV into the interior angle in the interior direction and the external angle in the center of flexible PV. When the angle of flexible PV was used as interior angle, the generation amount was increased by 15.79% and increased by 8.45% compared with the external angle. MPPT tracking is performed on the generation amount of the interior angle which has the most power after comparing the generation amount according to the bending shape of the flexible PV. This algorithm can be the most efficient method for the curtain wall using flexible PV because the bending pattern with the greatest amount of power generation may be different because the environment of the building applying the curtain wall is different.