• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.4
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• pp.795-803
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• 2017

This paper describes a dual-standard cryptographic processor that efficiently integrates two block ciphers ARIA and AES into a unified hardware. The ARIA-AES crypto-processor was designed to support 128-b and 256-b key sizes, as well as four modes of operation including ECB, CBC, OFB, and CTR. Based on the common characteristics of ARIA and AES algorithms, our design was optimized by sharing hardware resources in substitution layer and in diffusion layer. It has on-the-fly key scheduler to process consecutive blocks of plaintext/ciphertext without reloading key. The ARIA-AES crypto-processor that was implemented with a $0.18{\mu}m$ CMOS cell library occupies 54,658 gate equivalents (GEs), and it can operate up to 95 MHz clock frequency. The estimated throughputs at 80 MHz clock frequency are 787 Mbps, 602 Mbps for ARIA with key size of 128-b, 256-b, respectively. In AES mode, it has throughputs of 930 Mbps, 682 Mbps for key size of 128-b, 256-b, respectively. The dual-standard crypto-processor was verified by FPGA implementation using Virtex5 device.

• Korean Journal of Construction Engineering and Management
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• v.16 no.1
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• pp.35-43
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• 2015

It is important to have enough design and construction duration for infrastructure projects. However, recent water resource project in Korea shows several problems caused by their fast-tract schedule. National Audit Committee report several water resource projects have quality problems caused by insufficient project duration. Especially, water resource projects such as dam and water pipeline construction should have proper time to secure their structure quality. Normal project duration for these projects should be estimated based on previous similar projects' historical data analysis. However there is no standard model which can estimate normal project duration for water resource projects in Korea. There are several normal project duration estimation models for building project developed by public(LH) and private construction companies. However, there is no proper model for water resource projects. So, this study developed normal project duration model for dam and water pipeline projects using historical data and show application of models.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.12
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• pp.831-841
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• 2014

The attacker can access the RFID systems illegally because authentication operation on the RFID systems are performed in wireless communication. Authentication methods based on the PUF were presented to defend attacks. Because of Hash and AES, the cost is expensive for the low-cost RFID tag. In this paper, the PUF-based encryption processor and the mutual authentication protocol are proposed for low-cost RFID authentication. The challenge-response pairs (PUF's input and output) are utilized as the authentication key and encrypted by the PUF's characteristics. The encryption method is changed each session and XOR operation with random number is utilized. Therefore, it is difficult for the attacker to analyze challenge-response pairs and attack the systems. In addition, the proposed method with PUF is strong against physical attacks. And the method protects the tag cloning attack by physical attacks because there is no authentication data in the tag. Proposed processor is implemented at low cost with small footprint and low power.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.6
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• pp.80-88
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• 2008

In this paper, the block cipher algorithms, 3-DES(Triple Data Encryption Standard), AES(Advanced Encryption Standard), SEED, HASH(SHA-1), which are domestic and international standards, have been implemented as an integrated cryptographic engine for smart card applications. For small area and low power design which are essential requirements for portable devices, arithmetic resources are shared for iteration steps in each algorithm, and a two-level clock gating technique was used to reduce the dynamic power consumption. The integrated cryptographic engine was verified with ALTERA Excalbur EPXA10F1020C device, requiring 7,729 LEs(Logic Elements) and 512 Bytes ROM, and its maximum clock speed was 24.83 MHz. When designed by using Samsung 0.18 um STD130 standard cell library, the engine consisted of 44,452 gates and had up to 50 MHz operation clock speed. It was estimated to consume 2.96 mW, 3.03 mW, 2.63 mW, 7.06 mW power at 3-DES, AES, SEED, SHA-1 modes respectively when operating at 25 MHz clock. We found that it has better area-power optimized structure than other existing designs for smart cards and various embedded security systems.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.4
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• pp.41-49
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• 2010

This paper proposes a new high speed SHA-1 architecture using multiple unfolding and pre-computation techniques. We unfolds iterative hash operations to 2 continuos hash stage and reschedules computation timing. Then, the part of critical path is computed at the previous hash operation round and the rest is performed in the present round. These techniques reduce 3 additions to 2 additions on the critical path. It makes the maximum clock frequency of 118 MHz which provides throughput rate of 5.9 Gbps. The proposed architecture shows 26% higher throughput with a 32% smaller hardware size compared to other counterparts. This paper also introduces a analytical model of multiple SHA-1 architecture at the system level that maps a large input data on SHA-1 block in parallel. The model gives us the required number of SHA-1 blocks for a large multimedia data processing that it helps to make decision hardware configuration. The hs fospeed SHA-1 is useful to generate a condensed message and may strengthen the security of mobile communication and internet service.

• Journal of Digital Contents Society
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• v.9 no.4
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• pp.607-616
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• 2008

By the advancement of computer & network technology, the paridigm of 'Network Computer' has been realizing`. In what is called network computer, computer system and computing resource is incomparably seem to be expanded compared with conventional network technology[1]. Network connected computer system consitute a massive virtual computer, it is possible for people to use an enourmous amout of computing resource distributed widely through the network. It is also possible that we make client lightweight by the use of computer system & all shared computing resources on the network in our computer processing and we call this type of client system as thin-client. Thin-client and network computer are on and the same network paradigm in that both paradigm featuring the active use of computer system and resource on the network[2]. In network computer paragem, network itself is regarded as a basic platform for the transfer of application, so it is possible that client access remote serve system to run remote applications through the network[3]. In this paper, we propose the system architecture for the implementation of network computer by the use of Web browser, X window system and Pyjamas. By the use of network computer proposed in this paper, it is possible for people to run application on the server system as if he run local application, and it is expected to improve the security and maintenance efficiency.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.4 no.4
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• pp.43-61
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• 1981

Interest in the Quality of working life is spreading rapidly and the phrase has entered the popular vocabulary. That this should be so is probably due in large measure to changes in the values of society, nowadays accelerated as never before by the concerns and demands of younger people. But however topical the concept has become, there is very little agreement on its definition. Rather, the term appears to have become a kind of depository for a variety of sometimes contradictory meanings attributed to it by different groups. A list of all the elements it if held to cover would include availability and security of employment, adaquate income, safe and pleasant physical working conditions, reasonable hours of work, equitable treatment and democracy in the workplace, the possibility of self-development, control over one's work, a sense of pride in craftsmanship or product, wider career choices, and flexibility in matters such as the time of starting work, the number of working days in the week, Job sharing and so on altogether an array that encompasses a variety of traditional aspirations and many new ones reflecting the entry into the post industrial era. The term "quality of working life" was introduced by professor Louis E. Davis and his colleagues in the late 1960s to call attention to the prevailing and needlessly poor quality of life at the workplace. In their usage it referred to the quality of the relationship between the worker and his working environment as a whole, and was intended to emphasize the human dimension so often forgotten among the technical and economic factors in job design. Treating workers as if they were elements or cogs in the production process is not only an affront to the dignity of human life, but is also a serious underestimation of the human capabilities needed to operate more advanced technologies. When tasks demand high levels of vigilence, technical problem-solving skills, self initiated behavior, and social and communication skills. it is imperative that our concepts of man be of requisite complexity. Our aim is not just to protect the worker's life and health but to give them an informal interest in their job and opportunity to express their views and exercise control over everything that affects their working life. Certainly, so far as his work is concerned, a man must feel better protected but he must also have a greater feeling of freedom and responsibility. Something parallel but wholly different if happening in Europe, industrial democracy. What has happened in Europe has been discrete, fixed, finalized, and legalized. Those developing centuries driving toward industrialization like R.O.K, shall have to bear in mind the human complexity in processing and designing the work and its environment. Increasing attention is needed to the contradiction between autocratic rule at the workplace and democratic rights in society.n society.

• 모자간호학회지
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• v.3 no.1
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• pp.38-48
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• 1993

This study was done to suggest modification in the present hospital policy for Labour and Delivery which separates women in labour from their families. The design for study was a descriptive study. The number of subjects consisted of 82 postpartum women who had delivered within 12 hours and for whom there were no complications either for the mothers or for the newborns. Data collection was done with a structured questionnaire which was analyzed using frequencies and percentiles. The results of this study are as follows : 1. Most of subjects (90.2%) wanted their family to participate in the labour process. Husband were chosen as the primary participant(79.3%). The number of subjects who wanted their family to support them through the whole labour process (35.4%) was the highest, followed by, during labour(32.9%), as contrasted to, during delivery (1.2%). 2. Support from husband during pregnancy ranged from 55.6%-87.6% for all items. Primary support was from husband during the pregnancy. 3. The subjects wanted support from their families in labour by way of encouraging(84.1%), consolidating(81.7%), changing position(43.9%), maintaining relaxation(35.4%) and helping with respiration control (29.3%). The results showed higher support on the emotional level than the physical and informational level (26.8%). 4. The subjects answered that they expected that participation by their family during the labour process would have the effect of increasing security for the women in labour(79.3%), providing a better relationship between the family and the women in labour (57.3%) and the newborns(34.1%), and making for an easier labour courses (23.2%). 5. The priority of family members that the subjects wanted support from was, the husband, mother and mother-in-law in that order. It can be concluded that nurses help to maintain a management policy in the maternity setting which ignores the needs of the women in labour. If consideration is to be given to these subjects, future programs should include participation by the family in the labour process.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.8
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• pp.1588-1596
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• 2015

In the Internet of Things (IoT), resource-constrained devices such as sensors are capable of communicating and exchanging data over the Internet. The IETF standard group has specified an application protocol CoAP, which uses UDP as a transport protocol, allows such a lightweight device to transmit data. Also, the IETF recommended the DTLS binding for securing CoAP. However, additional features should be added to the DTLS protocol to resolve several problems such as packet loss, reordering, fragmentation and replay attack. Consequently, performance of DTLS is worse than TLS. It is highly required for lightweight devices powered by small battery to design and implement a security protocol in an energy efficient manner. This paper thus discusses about DTLS performance in the perspective of energy consumption. To analyze the performance, we implemented IEEE 802.15.4 based test network consisting of constrained sensor devices in the Cooja simulator. We measured energy consumptions required for each of DTLS client and server in the test network. This paper compares the energy consumption and amount of transmitted data of each flight of DTLS handshake, and the processing and receiving time. We present the analyzed results with regard to code size, cipher primitive and fragmentation as well.

• The Korean Journal of Financial Management
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• v.24 no.3
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• pp.29-62
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• 2007

We examine the methods to increase MBS values given parameters of default risks of individual mortgages and their correlation, and analyze the effects of these parameters on the efficiency of the methods. First, the values of MBS can be improved when they are comprised of low-correlation mortgages regardless of specific forms of investors' utility functions. Second, the values of MBS can also be raised even after their components mortgages are determined. More specifically, when investors' utilities are heterogeneous, CMO's of a less risky tranche and a riskier tranche are highly valued compared with pass-through securities of two identical tranches. When investors' utilities are homogeneous(risk averse), however, the latter meets the needs of investors better than the former does. Third, it can be shown that the efficiency of the methods in this paper is an increasing function of default risks of mortgage loans or of the correlation between them, and a decreasing function of the amount of the price fall of MBS when in default.