• Journal of Internet of Things and Convergence
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• v.6 no.2
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• pp.25-29
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• 2020

The elliptic curve crypto-algorithm is widely used in authentication for IoT environment, since it has small key size and low communication overhead compare to the RSA public key algorithm. If the scalar multiplication, a core operation of the elliptic curve crypto-algorithm, is not implemented securely, attackers can find the secret key to use simple power analysis or differential power analysis. In this paper, an elliptic curve scalar multiplication algorithm using a randomized scalar and an elliptic curve point blinding is suggested. It is resistant to power analysis but does not significantly reduce efficiency. Given a random r and an elliptic curve random point R, the elliptic scalar multiplication kP = u(P+R)-vR is calculated by using the regular variant Shamir's double ladder algorithm, where l+20-bit u≡rn+k(modn) and v≡rn-k(modn) using 2^lP=∓cP for the case of the order n=2^l±c.

• Proceedings of the CALSEC Conference
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• 1999.07a
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• pp.193-205
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• 1999

Nowadays, public domain software CALS/EC projects give their attention to the importance of test and evaluation (T＆E). This article proposed a survey on T＆E procedures of the international standards ISO 9000-3, ISO/IEC 9126 and ISO 14598, and of the U.S. Army pamphlet as well as that of MIL-STD-498. And features of testing tools such as their characteristics were reviewed for a reference in selecting appropriate one. Large-scale software projects often encounter with problems during T＆E, when they become close to the end of development cycle. The problems generally act as a bottleneck of a project, leading to slippage of the entire schedule. This article tried a close look at the problems and solution alternatives of the T＆E policy, management, and technical issues, and proposed a T＆E model to support a variety of software development environment.

• Journal of Korean Neurosurgical Society
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• v.46 no.5
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• pp.472-478
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• 2009

Objective : Hyaluronidase (HAse), a degrading enzyme of hyaluronic acid (HA), is highly expressed in patients with malignant glioma. The purpose of this study was to verify whether HAse is related to the invasion of glioma cells. We also investigated if glioma cells with higher mobility in 2-dimensioal (2-D) method have also higher mobility at 3-dimensional (3-D) environment. Methods : Malignant glioma cell lines (U87MG, U251MG, U343MG-A, and U373MG) were used, and their HAse expressions were evaluated by HA zymography. The migration ability was evaluated by simple scratch technique. The invasiveness of each cell lines was evaluated by Matrigel invasion assay and HA hydrogel invasion assay. In HA hydrogel invasion assay, colonies larger than $150\;{\mu}m$ were regarded as positive ones and counted. Statistical analysis of migration ability and invasion properties of each cell lines was performed using t-test. Results : In scratch test to examine migration ability of each cell lines, U87MG cells were most motile than others, and U343MG-A least motile. The HAse was expressed in U251MG and U343MG-A cell lines. However, U87MG and U373MG cell lines did not express HAse activity. In Matrigel invasion assay, the cell lines expressing HAse (U251MG and U343MG-A) were more invasive in the presence of HA than HAse deficient cell lines (U87MG and U373MG). In HA hydrogel invasion assay, the HAse-expressing cell lines formed colonies more invasively than HAse-deficient ones. Conclusion : Malignant Glioma cells expressing HAse were more invasive than HAse-deficient ones in 3-dimensional environment. Therefore, it might be suggested that invasion of malignant gliomas is suppressed by inhibition of HAse expression or HA secretion. Additionally, the ability of 2-D migration and 3-D invasion might not be always coincident to each other in malignant glioma cells.

• Journal of Aquaculture
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• v.16 no.3
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• pp.159-164
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• 2003

Effect of the benthic echiurid Urechis unicinctus juveniles on the chemical characteristics of organically enriched sediment, as well as the individual survival rate and growth in various sediments, was investigated in this study to ascertain the effectiveness of U. unicinctus in the bioremediation of organically polluted sediment. The content of acid volatile sulfide (AVS) in the sediment of three coastal areas was 0.4±0.1 mg/gㆍdry sediment in Seonso, 0.1±0.01 mg/gㆍdry sediment in Myo-do, 0.02±0.01 mg/gㆍdry sediment in Dolsan-do, respectively. 500 juveniles with average body length of 1.2±0.3 mm were bred in these sediments. After 30 days, the AVS content of three places decreased to 0.29±0.3, 0.08±0.01 and 0.0l±0.01 mg/gㆍdry. After 60 days, the content was 0.23±0.03, 0.0l±0.01, 0.0l±0.01 mg/gㆍdry. The AVS content in the control (sediment from Seonso without juveniles) was 0.39±0.75 mg/gㆍdry sediment (after 30 days) and 0.45±0.01 mg/gㆍdry sediment (after 60 days). At the same time, the chemical oxygen demand (COD) and total ingition loss (TIL) of these sediments showed the same trend with that of AVS. Furthermore, 60 days later, the survival rate and growth of juveniles were 71.2%, 11.1±l.0 mm in Seonso, 89.8%, 12.0±1.3 mm in Myo-do and 81.6%, 11.9±1.9 mm in Dolsan-do. It was suggested that U. unicinctus can survive better in less polluted environment. Under different U. unicinctus juvenile density (100, 300, 500, 700, 900 individuals), after 60 days cultivation, the AVS content decreased from 0.4±0.1, 0.4±0.1, 0.4±0.3, 0.4±0.3, 0.4±0.3 mg/gㆍdry to 0.4±0.2, 0.3±0.2, 0.2±0.1, 0.2±0.1, 0.2±0.1 mg/gㆍdry. Therefore, the higher the density of juveniles, the greater the effect in improving the sediment. In comparison to different initial AVS concentration (0.40±0.01, 0.35±0.01, [I can't find a reference to this number above], 0.29±0.02, [I can't find a reference to this number above], 0.18±0.03, [I can't find a reference to this number above], 0.06±0.02 mg/gㆍdry sediment [I can't find a reference to this number above] and the control 0.0±0.0[I can't find a reference to this number above]), after 30 days cultivation with 500 juveniles, the AVS content was 0.29±0.03, 0.19±0.0, 0.15±0.01, 0.12±0.02, 0.05±0.0mg/gㆍdry and 0(control). After 60 days cultivation, the content was 0.23±0.03, 0.12±0.4, 0.10±0.01, 0.18±0.03, 0.06±0.02 mg/gㆍdry and 0 (control). Use % decrease in AVS content to state: The impact of U. unicinctus on the sediments was greater with higher concentrations of AVS. The results of this study indicate that U. unicinctus is effective in the biological treatment of sediments polluted by AVS and other organics.

• Korean journal of applied entomology
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• v.54 no.4
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• pp.345-349
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• 2015

The pest species occurring on the aboveground parts of Phalaenopsis orchids were studied for a period of two years (Aug. 2013 to June 2015) at 9 Phalaenopsis farms in Korea. In total, 10 species of insect pest were identified : Tenuipalpus pacificus Baker, Tyrophagus putrescentiae Schrank, Frankliniella occidentalis Pergande, Frankliniella intonsa Trybom, Thrips tabaci Lindeman, Scirtothrips dorsalis Hood, Pseudococcus dendrobiorum Williams, Pseudococcus longispinus Targioni Tozzetti, Coccus hesperidum L., Limax marginatus $M{\ddot{u}}ller$. T. pacificus occurred in most of the farms surveyed in this study (6). The observation frequency of T. pacificus and F. intonsa were highest, they were observed in 10 out of 96 surveys. Although P. longispinus was only observed to occur on two farms, their observation frequency (9 observations, 9.4%) and density (2-289 per 20 plants) were high. Thus, it seems that T. pacificus, F. intonsa, and P. longispinus are the major pests affecting Phalaenopsis orchid farms in Korea.

• Journal of Internet Computing and Services
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• v.19 no.6
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• pp.31-40
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• 2018

With the development of IT technology recently, medical information systems are being constructed in an integrated u-health environment through cloud services, IoT technologies, and mobile applications. These kinds of medical information systems should provide the medical staff with authorities to access patients' medical information for emergency status treatments or therapeutic purposes. Therefore, in the medical information systems, the reliable and prompt authentication processes are necessary to access the biometric information and the medical information of the patients in charge of the medical staff. However, medical information systems are accessing with simple and static user authentication mechanism using only medical ID / PWD in the present system environment. For this reason, in this paper, we suggest a dynamic situation authentication mechanism that provides transparency of medical information access including various authentication factors considering patient's emergency status condition and dynamic situation authentication system supporting it. Our dynamic Situation Authentication is a combination of user authentication and mobile device authentication, which includes various authentication factor attributes such as emergency status, role of medical staff, their working hours, and their working positions and so forth. We designed and implemented a dynamic situation authentication system including emergency status decision, dynamic situation authentication, and authentication support DB construction. Finally, in order to verify the serviceability of the suggested dynamic situation authentication system, the medical staffs download the mobile application from the medical information server to the medical staff's own mobile device together with the dynamic situation authentication process and the permission to access medical information to the patient and showed access to medical information.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.890-891
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• 2015

With South Korea entering aging society, the problem of the elderly living alone is aggravating due to increasing health risks associated with social isolation. This should be counteracted by providing them with supports conducive to the recovery of social relationship and effective management of daily activities, such as health checkups, homecare services, chore services, and contents building for information service. This paper presents a human care system implementing miniaturization and portability for the elderly and other care recipients by integrating various contents into recipients' situation perception, direct experience, and sensor modules as a smartphone application in Internet of Things environment to facilitate their health status monitoring.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.4
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• pp.13-23
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• 2017

In order to protect personal information and important information (confidential information, sales information, user information, etc.) in the internal network, companies and organizations apply encryption to the Server-To-Server or Server-To-Client communication section, And are experiencing difficulties due to the increasing number of known attacks and intelligent security attacks. In order to apply the existing S / W encryption technology, it is necessary to modify the application. In the financial sector, "Comprehensive Measures to Prevent the Recurrence of Personal Information Leakage in the Domestic Financial Sector" has been issued, and standard guidelines for financial computing security have been laid out, and it is required to expand the whole area of encryption to the internal network. In addition, even in environments such as U-Health and Smart Grid, which are based on the Internet of Things (IoT) environment, which is increasingly used, security requirements for each collection gateway and secure transmission of the transmitted and received data The requirements of the secure channel for the use of the standard are specified in the standard. Therefore, in this paper, we propose a secure encryption algorithm through mutual authentication and grouping for each node through H / W based Network Control Server (NCS) applicable to internal system and IoT environment provided by enterprises and organizations. We propose a protocol design that can set the channel.

• Journal of Korean society of Dental Hygiene
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• v.2 no.1
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• pp.115-129
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• 2002

The purpose of this study was to examine the actual dental hygiene status of workers in cement industry in an effort to serve as a basis for enhancing their dental hygiene. The subjects in this study were 420 laborers from the cities of Curi, Donghae and Samcheok who handled cement. As a result of conducting a survey, the following findings were given : l. The workers investigated found their working environment satisfactory, getting a mean score of 323. They also expressed a high job satisfaction with a mean score of 333. 2. They didn't have a big interest in oral health. By age group, those who were aged between 36 and 40, or who cared less about health management, showed a higher interest in oral health. Besides, the laborers who kept smoking for a longer period, or who drunk more, expressed greater interest. 3. The toothbrushing method was considered most important for periodontal health, by 45.0% of the workers, and the next most crucial one was regular dental examination, followed by refraining from smoking and staying away from sweet food in the order named. 4. Concerning daily mean toothbrushing frequency, 455% brushed their teeth three times a day on the average. More than half them didn't pay enough attention to toothbrushing. 5. Regarding scaling, the large number of the workers, 42.4%, had no experience to get their teeth scaled, 37.6%, the greatest percentage, didn't have their teeth scaled because it seemed to make their teeth painful or cold. 6. As fororal health education experience, 67.6%, the great number of them, had no experience to receive dental health education. The above-mentioned findings suggest that the cement-related workers generally neglected dental health management. They should be encouraged to correct their wrong oral health knowledge or habit to make their oral cavity more healthy. To make it happen, it's required to provide oral health education and promote organized dental health projects.

• Journal of Fashion Business
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• v.25 no.4
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• pp.1-13
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• 2021

As interest in skin care increases, this study aims to contribute to the development of the beauty self-care market by providing basic data through the measurement of the oil and moisture skin condition of women in their 20s and 30s. The study was conducted from November 27, 2020 to January 31, 2021, with 20 women in their 20s and 30s divided into 4 groups, A~D, by age, 5 per group. Skin measurements were taken four times at 4 hour intervals at 0H, 4H, 8H, and 12H based on the first measurement that was taken within 30 minutes after waking up, and the oil and moisture indices were observed over time. As a result, both T and U zones showed significant differences in moisture levels over time, with no difference between groups for both T and U zones. Moisture decreased the most between 0H to 4H, and moisture changed the least between 4H to 8H. Changes in moisture increased the similar at 0H and 12H. The oil condition changed more irregularly compared to moisture over time, but all groups showed lower oil content in the U-zone compared to the T-zone. Overall, the facial oil and moisture conditions of women in their 20s and 30s changed over time, indicating that the skin changes in real time. The fact that the skin data, which was measured in the primary activity living environment, can be used as basic research data in the beauty self-care market is meaningful.