• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.20 no.5
• /
• pp.23-36
• /
• 2010

Signcryption is a cryptographic primitive which offers authentication and confidentiality simultaneously with a cost lower than signing and encrypting the message independently. We propose a new cryptographic notion called Identity-based online/offline signcryption. The notion of online/offline scheme can be divided into two phases, the first phase is performed offline prior to the arrival of a message to be signed or encrypted and the second phase is performed online phase after knowing the message and the public key of recipient. The Online phase does not require any heavy computations such as pairings or exponents. It is particularly suitable for power-constrained devices such as smart cards. In this paper, we propose ID-based signcryption scheme and ID-based online/offline signcryption scheme where the confidentiality and authenticity are simultaneously required to enable a secure and trustable communication environment. To our best knowledge, this is the first ID-based online/offline signcryption scheme that can be proven secure in the standard model.

• The Journal of Bigdata
• /
• v.5 no.2
• /
• pp.241-255
• /
• 2020

In Korea, utilizing and protecting the ocean from the sea on three sides can be considered the basis of national power. Recently, it has been distributed to IOT and 5G networks, and attempts to provide various information based on telecommunication infrastructure are continuing in the public and private sectors. In this study, an online survey was conducted with the aim of improving the services of marine information services (KOMC, safe and open seas) provided by the Government Agency for Oceanographic Research. Through an online survey, the survey was conducted on sites that are mainly used to survey people's need for marine information and to collect information. In addition, the survey was conducted on the UX, UI problems and improvements of KOMC, open and safe sea sites provided by the National Oceanographic Research Institute. The awareness and experience of marine information service by the Korea Oceanographic Research Institute were confirmed. Later, the previous steps of FGI also examined the usability of various users after allowing them to use the actual service. Here, the experience of collecting marine information from actual users was investigated, not just by looking at and evaluating the design of the service website and application. As a result, users presented a variety of opinions related to marine information services, including accessibility, reliability of information, providing media, and importance of information provided. The findings could be used as data to identify ocean-related data and ways to provide information required by users of various age groups and occupational groups.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.39 no.3
• /
• pp.149-156
• /
• 2021

This study collected and analyzed case studies related with the use of spatial information in North Korea to prioritize construction and required supporting processes in order to propose a short-term and long-term road map for the establishment of spatial information in North Korea. Recent research cases related to the prioritization of spatial information development were analyzed, and priority for the construction of infrastructure was derived based on the interconnectedness and relationship of national infrastructure. Due to the inaccessibility and remoteness of North Korea, all of the five studies determined priorities according to questionnaires and consulting of refugees and knowledgeable figures by expert groups. In summary, priority was given to unarmed and transborder areas, major cities, special zones, and development zones, while in terms of facilities, priority was given to power communication, railroads, water and sewage architectural buildings, roads, and dams. In the case of prioritizing the establishment of national infrastructure for the unified Korean Peninsula, the development of major areas, ports, and the related city-level spots to develop a line that promotes the sharing of routes such as transportation networks, water, and energy, thus leading to a scenario involving the development of cotton at an urban and national level.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.12
• /
• pp.192-199
• /
• 2020

The blower erosion phenomenon was investigated to develop a long-life blower with a volume flow rate of 10,000 ㎥/min with the required total pressure efficiency of 83% or more. The blower performance and blower erosion were predicted through numerical analysis by computational fluid dynamics(CFD). The conditions used for numerical analysis were an air volume of 16,200 ㎥/min, a rotation speed of 893 rpm, and a temperature of 330℃. The specific gravity, particle size, and amount of the dust was 3.15, 90 ㎛~212 ㎛, and is 265 kg/min, respectively. To examine the effects of a dust deflector on erosion, erosion analysis was performed by comparing the models with and without a dust deflector. Numerical analysis showed that when the dust deflector is installed, the average tended to decrease by 167% in the impeller and 133% in the boss. CFD using the Finne's model for erosion revealed a parallel restitution coefficient of 1 and a perpendicular restitution coefficient of 0.1. The blower performance of case 5 was 691.7 mmAq, and the efficiency was 83.3% when the rotation speed and the air volume flow rate were 880 rpm and 16,200 ㎥/min, respectively.

• Journal of the Microelectronics and Packaging Society
• /
• v.28 no.2
• /
• pp.89-94
• /
• 2021

The mechanical reliability of flexible devices has become a major concern on their commercialization, where the importance of reliable bonding is highlighted. In terms of component materials' properties, it is important to consider thermal damage of polymer substrates that occupy large area of the flexible device. Therefore, room temperature bonding process is highly advantageous for implementing flexible device assemblies with mechanical reliability. Conventional epoxy resins for the bonding still require curing at high temperatures. Even after the curing procedure, the bonding joint loses flexibility and exhibits poor fatigue durability. To solve this problems, low-temperature and adhesive-free bonding are required. In this work, we develop a room temperature bonding process for polymer substrates using carbon nanotube heated by microwave irradiations. After depositing multiple-wall carbon nanotubes (MWNTs) on PET polymer substrates, they are heated locally with by microwave while the entire bonding specimen maintains room temperature and the heating induces mechanical entanglement of CNT-PET. The room temperature bonding was conducted for a PET/CNT/PET specimen at 600 watt of microwave power for 10 seconds. Thickness of the CNT bonding joint was very thin that it obtains flexibility as well. In order to evaluate the mechanical reliability of the joint specimen, we performed lap shear test, three-point bending test, and dynamic bending test, and confirmed excellent joint strength, flexibility, and bending durability from each test.

• Journal of Biomedical Engineering Research
• /
• v.43 no.1
• /
• pp.11-18
• /
• 2022

An electromagnetic generator with variable stimulation parameters is required to conduct basic research on magnetic flux density and frequency for pulsed electromagnetic fields (PEMFs). In this study, we design an electromagnetic generator that can conduct basic research by providing parameters optimized for cell and animal experimental conditions through adjustable stimulation parameters. The magnetic core was selected as a solenoid capable of uniform and stable electromagnetic stimulation. The solenoid was designed in consideration of the experimental mouse and cell culture dish insertion. A voltage and current adjustable power supply for variable magnetic flux density was designed. The system was designed to be adjustable in frequency and pulse width and to enable 3-channel output. The reliability of the system and solenoid was evaluated through magnetic flux density, frequency, and pulse width measurements. The measured magnetic flux density was expressed as an image and qualitatively observed. Based on the acquired image, the stimulation area according to the magnetic flux density decrease rate was extracted. The PEMF frequency and pulse width error rates were presented as mean ± SD, and were confirmed to be 0.0928 ± 0.0934% and 0.529 ± 0.527%, respectively. The magnetic flux density decreased as the distance from the center of the solenoid increased, and decreased sharply from 60 mm or more. The length of the magnetic stimulation area according to the degree of magnetic flux density decrease was obtained through the magnetic flux density image. A PEMF generator and stimulation parameter control system suitable for cell and animal models were designed, and system reliability was evaluated.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.42 no.4
• /
• pp.493-499
• /
• 2022

The standards pertaining to the quality of discharged water in sewage treatment plants are strengthening, and accordingly, facilities in sewage treatment plants are being upgraded. In addition, the discharge water quality of sewage treatment plants must be maintained at a high level, and efficient sewage treatment plant operations have thus emerged as a very important issue. For the efficient operation of sewage treatment plants, this study applied a basic blowing amount calculation method based on sewage facilities to evaluate the required oxygen amount and blowing amount according to inflow water quality by logicizing various influencing factors. As a result of calculating the amount of air blown by applying actual April water quality data from sewage treatment plant A to the blower demand calculation developed through this study, it was found that the average amount of air blown was reduced by about 12%. When the blower demand calculation developed here is applied to an actual sewage treatment plant, the amount of air blown can be controlled based on the inflow water quality. This can facilitate the realization of an autonomous control of sewage treatment plants, in contrast to the existing sewage treatment operation method that relies on operational experience of operator. In addition, it is expected that efficient sewage treatment plants can be operated by reducing blowing amounts and power costs, which will contribute to both energy and carbon savings.

• Journal of Industrial Convergence
• /
• v.20 no.6
• /
• pp.93-104
• /
• 2022

This study was done to identify the factors affecting the problem-solving ability of nursing students who have received online psychiatric nursing practice. The subjects of the study were 280 fourth-grade nursing students. The data were subjected to descriptive statistics, 𝑥²-test, t-test, one-way ANOVA, Pearson's correlation analysis, and multiple regression analysis using the SPSS 24.0 program. As a result of the analysis, the mean of each variable was learning satisfaction 4.03±.70, self-efficacy in learning 5.69±.82, transfer motivation 5.52±.86, and problem-solving ability was 3.65±.41. Learning satisfaction and problem-solving ability (r=.387, p<.001), self-efficacy in learning and problem-solving ability (r=.576, p<.001), transfer motivation and problem-solving ability (r=.536, p <.001) showed a significant correlation. Factors affecting problem-solving ability were gender (𝛽=.11), grade point average (𝛽=.12), motivation of personal major choice (𝛽=-.12), satisfaction of major (𝛽=.13), self-efficacy in learning (𝛽=.36) and transfer motivation (𝛽=.16), and the explanatory power of variables was 41.4%. Based on the results of this study, a follow-up study is required to identify the causal relationship between variables related to problem-solving ability.

• Journal of IKEEE
• /
• v.26 no.3
• /
• pp.422-429
• /
• 2022

A light sensor chip requires a small capacity eFuse (electrical fuse) OTP (One-Time Programmable) memory IP (Intellectual Property) to trim analog circuits or set initial values of digital registers. In this paper, 128-bit eFuse OTP IP is designed using only 3.3V MV (Medium Voltage) devices without using 1.8V LV (Low-Voltage) logic devices. The eFuse OTP IP designed with 3.3V single MOS devices can reduce a total process cost of three masks which are the gate oxide mask of a 1.8V LV device and the LDD implant masks of NMOS and PMOS. And since the 1.8V voltage regulator circuit is not required, the size of the illuminance sensor chip can be reduced. In addition, in order to reduce the number of package pins of the illumination sensor chip, the VPGM voltage, which is a program voltage, is applied through the VPGM pad during wafer test, and the VDD voltage is applied through the PMOS power switching circuit after packaging, so that the number of package pins can be reduced.

• The Korean Society of Law and Medicine
• /
• v.22 no.4
• /
• pp.159-184
• /
• 2021

The significance of the enactment of the 「Act On The Safety Of And Support For Advanced Regenerative Medicine And Advanced Biological Products」 is to break away from the regulation of the Pharmaceutical Affairs Act and expand patient treatment opportunities through a medical technology approach to regenerative medicine, which is essentially a medical practice called 'transplantation'. However, more than a year after the law was enacted, clinical study has not been activated, with not a single high-risk study approved by the Ministry of Food and Drug Safety being approved. The reason is that despite the legal purpose of expanding patient treatment opportunities, the data requirements for clinical study approval are set in connection with drug development despite the insufficient legal basis, making it difficult for many researchers to meet the data requirements. Prior to the enactment of the Act, submitted data for clinical study on cell therapy products within the Pharmaceutical Affairs Act were cosiderably exempted from quality and non-clinical test data, but with the enforcement of the Advanced Regenerative Bio Act, quality and non-clinical test data are required in accordance with pharmaceuticals when applying for approval of a clinical study plan. To rectify this, when considering the identity of clinical study on advanced regenerative medicine to expand treatment opportunities, recognize that there are limitations in connection with drug development. And it is necessary to preserve the identity of clinical study on advanced regenerative medicine, and on the other hand, in the case of drug product approval, clinical study results should be utilized while specifying usage requirements. Therefore, with the power of the market and the voluntary motive of the clinical researcher, it is necessary to prepare the necessary data by themselves rather than the basic requirements for clinical study approval.