• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.9
• /
• pp.1993-1999
• /
• 2011

This paper describes a design of area-efficient/low-power cryptographic processor for HIGHT block cipher algorithm, which was approved as standard of cryptographic algorithm by KATS(Korean Agency for Technology and Standards) and ISO/IEC. The HIGHT algorithm, which is suitable for ubiquitous computing devices such as a sensor in USN or a RFID tag, encrypts a 64-bit data block with a 128-bit cipher key to make a 64-bit cipher text, and vice versa. For area-efficient and low-power implementation, we optimize round transform block and key scheduler to share hardware resources for encryption and decryption. The HIGHT64 core synthesized using a 0.35-${\mu}m$ CMOS cell library consists of 3,226 gates, and the estimated throughput is 150-Mbps with 80-MHz@2.5-V clock.

• Journal of Electrical Engineering and Technology
• /
• v.10 no.4
• /
• pp.1726-1733
• /
• 2015

In order to study the effect of the high-altitude and dusty weather in northwest of China on the corona characteristics of transmission lines, a corona caged based experimental system with sandy and dusty flow condition is numerically investigated and designed. This system overcomes the difficulties caused by harsh environment and offers easy usage for off-site tests. The design parameters are mainly determined by the characteristics of strong sandstorm in northwest region and test requirements. By the comparison of numerical simulation of the particle diffusion in four programs with rectangular or circular air-duct, a practical technology, which introduces swirl to control the particle diffusion length, is obtained. Accordingly, the structure of round air-duct with swirl elbow in inlet and outlet of high level segment is selected as final program. Systems of control and measurement are designed at the same time. Field tuning results show that the test system could ensure the range of sandy and dusty coverage. The wind speed, sandy and dusty concentration could be controlled and meet the requirements of accuracy. The experimental system has many features, such as simple structure, easy to be assembled, disassembled, transported and operated, small space occupied.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2011.05a
• /
• pp.125-128
• /
• 2011

This paper describes an efficient hardware implementation of HIGHT block cipher algorithm, which was approved as standard of cryptographic algorithm by KATS(Korean Agency for Technology and Standards) and ISO/IEC. The HIGHT algorithm, which is suitable for ubiquitous computing devices such as a sensor in USN or a RFID tag, encrypts a 64-bit data block with a 128-bit cipher key to make a 64-bit cipher text, and vice versa. For area-efficient and low-power implementation, we optimize round transform block and key scheduler to share hardware resources for encryption and decryption. The HIGHT64 core synthesized using a $0.35-{\mu}m$ CMOS cell library consists of 3,226 gates, and the estimated throughput is 150-Mbps with 80-MHz@2.5-V clock.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.41 no.12
• /
• pp.67-74
• /
• 2004

AES is frequently used as a symmetric cryptography algorithm for the Internet. Wireless embedded systems increasingly use more conventional wired network protocols. Hence, it is important to have low-cost implementations of AES for thor The basic architecture of AES unrolls oかy one full cipher round which uses 20 S-boxes together with the key scheduler and the algorithm repeatedly executes it. To reduce the implementation cost further, the folded architecture which uses only eight S-box units was studied in the recent years. In this paper, we will study a low-cost AES implementation for wireless communication technology based on the folded architecture. We first improve the folded architecture to avoid the sixteen bytes of additional state memory. Then, we implemented a single byte architecture where only one S-box unit is used for data encryption and key scheduling. It takes 352 clocks to finish a complete encryption. We found that the maximum clock frequency of its FPGA implementation reaches about 40 MHz. It can achieve about 13 Mbps which is enough for 3G wireless communication technology.

• Convergence Security Journal
• /
• v.7 no.2
• /
• pp.107-118
• /
• 2007

Distributed wireless sensor network in various environment have characteristic that is surveillance of environment-element and offering usefully military information but there is shortcoming that have some secure risks. Therefore secure service must be required for this sensor network safety. More safe and effective techniques of node administration are required for safe communication between each node. This paper proposes effective cluster-header and clustering techniques in suitable administration techniques of group-key on sensor network. In this paper, first each node transmit residual electric power and authentication message to BS (Base-Station). BS reflects "Validity Authentication Rate" and residual electric power. And it selects node that is more than these regularity values by cluster header. After BS broadcasts information about cluster header in safety and it transmits making a list of information about cluster member node to cluster header. Also, Every rounds it reflects and accumulates "Validity Authentication Rate" of former round. Finally, BS can select more secure cluster header.

• Asian-Australasian Journal of Animal Sciences
• /
• v.32 no.8_spc
• /
• pp.1284-1295
• /
• 2019

Considerable progress in reproduction of dairy goats has been made, with advances in reproductive technology accelerating dairy goat production since the 1980s. Reproduction in goats is described as seasonal. The onset and length of the breeding season is dependent on various factors such as breed, climate, physiological stage, male effect, breeding system, and photoperiod. The reproductive physiology of goats was investigated extensively, including hypothalamic and pituitary control of the ovary related to estrus behavior and cyclicity etc. Photoperiodic treatments coupled with the male effect allow hormone-free synchronization of ovulation, but the kidding rate is still less than for hormonal treatments. Different protocols have been developed to meet the needs and expectations of producers; dairy industries are subject to growing demands for year round production. Hormonal treatments for synchronization of estrus and ovulation in combination with artificial insemination (AI) or natural mating facilitate out-of-season breeding and the grouping of the kidding period. The AI with fresh or frozen semen has been increasingly adopted in the intensive production system, this is perhaps the most powerful tool that reproductive physiologists and geneticists have provided the dairy goat industry with for improving reproductive efficiency, genetic progress and genetic materials transportation. One of the most exciting developments in the reproduction of dairy animals is embryo transfer (ET), the so-called second generation reproductive biotechnology following AI. Multiple ovulation and ET (MOET) program in dairy goats combining with estrus synchronization (ES) and AI significantly increase annual genetic improvement by decreasing the generation interval. Based on the advances in reproduction technologies that have been utilized through experiments and investigation, this review will focus on the application of these technologies and how they can be used to promote the dairy goat research and industry development in the future.

• Journal of architectural history
• /
• v.23 no.4
• /
• pp.91-100
• /
• 2014

There are lots of and kinds of stone pagoda and stone Buddhas at Unjusa Temple in Hwasun, Jeonnam, which is thus called as Cheontap(千塔) or Cheonbul.(千佛) Several archaeological excavations have been conducted in Unjusa though, the foundation purpose or background motivation is yet wrapped in mystery. Circular shape is representative pagoda of Unjusa made of round frame or spherical roof but circular stone pagoda is unusual that there is no similar example found in India or China as well as in Korea. Located in the symbolic center, Circular stone pagoda is a key to understand Unjusa. Yundeung(輪燈) is made of stone for circular stone pagoda and there are craft lamp and large lamp. The large lamp, for the palace courtyard on the occasion of Palgwanhoe,(八關會) consists of discs and light on each disc. Outdoor lamp of circular stone pagoda made of stone for permanent preservation purpose. Unjusa is a very special temple with stone-yundeung for circular stone pagoda. In this study, a circular stone pagoda that is the source of yundeung said. Unjusa circular stone pagoda next to the title of 'yundeung pagoda' and proposes to call.

• Journal of Korea Multimedia Society
• /
• v.19 no.12
• /
• pp.2014-2023
• /
• 2016

Web presence is one of the key issues for extensive deployment of Internet-of-Things (IoT). An obstacle to overcome for Web presence is relatively low computing power of IoT devices. In this paper, we present implementation of an IoT platform based on Constrained Application Protocol (CoAP) which is a web transfer protocol proposed by Internet Engineering Task Force (IETF) for the low performance IoT devices such as Wireless Sensor Network (WSN) nodes and micro-controllers. To qualify the performance of CoAP-based IoT system for such an application as smart grid, we designed a test platform consisting of Raspberry Pi2, Kmote WSN node and a desktop PC. Using open source softwares, CoAP was implemented on top of the platform. Leveraging the GET command defined at CoAP specification, performance of the system was measured in terms of round-trip time (RTT) from web application to the Kmote sensor node. To investigate abnormal cases among the test results, hop-by-hop delays were measured to analyze resulting data. The average response time of CoAP-based communication except the abnormal data was reduced by 23% smaller than the previous research result.

• Structural Engineering and Mechanics
• /
• v.68 no.1
• /
• pp.95-101
• /
• 2018

The low rate of penetration and short lifetime of drilling bit served as the most common problems encountered in hard formation drilling, thus leading to severe restriction of drilling efficiency in oil and gas reservoir. This study developed a new local impact drilling method to enhance hard formation drilling efficiency. The limitation length formulas of radial/lateral cracks under static indentation and dynamic impact are derived based on the experimental research of Marshall D.B considering the mud column pressure and confining pressure. The local impact rock breaking simulation model is conducted to investigate its ROP raising effect. The results demonstrate that the length of radial/lateral cracks will increase as the decrease of mud pressure and confining pressure, and the local impact can result in a damage zone round the impact crater which helps the rock cutting, thus leading to the ROP increase. The numerical results also demonstrate the advantages of local impact method for raising ROP and the vibration reduction of bit in hard formation drilling. This study has shown that the local impact method can help raising the ROP and vibration reduction of bit, and it may be applied in drilling engineering.

• Journal of Agricultural Extension & Community Development
• /
• v.4 no.1
• /
• pp.57-72
• /
• 1997

Korean agriculture and rural sector has undergone a wide range of reform after the Uruguay Round. Major policy measure is to put finances of huge budget from tax payers since 1994 in preparation of the Rural Development Strategy and Reform Program. Both in the total amount and individual size of the subsidy and loan for eligible farmers and farmers group are large and drastically enormous than any other programs in the past. The strategy adopted was a bottom-up approach, Particularly in selecting the project with local autonomy. However, it has been still criticized as the form of centralized control of budget and decsion. In terms of the program effectiveness too, it is doubtful to judge that Korean agriculture is in a road to getting the international competetiveness as targeted. Since the local autonomy was started in 1995, the political structure has been settling in a way to be more locally institutionalized. Rural development policy, as the key point of economic and industrial dimension of local autonomy, should be initiated and practiced in real term by the local government. This paper, in this concern, in reviewing the past rural development prolicy and programs, discussed the necessary issues relevant to legal bases of land uses in Korea. Further, the direction of increasing local automous power of local government was discussed in the senses of budgetary control and decision. The power and budget should be allocated more to the rural development plans of local government in order to fulfilize integrated rural spatial development in this new era of globalization.