• Plant Journal
• /
• v.16 no.4
• /
• pp.26-32
• /
• 2020

The performance monitoring system in the power plant should have the capability to estimate power generation efficiency accurately. Several power generation efficiency models have been proposed for the combined heat and power (CHP) plant which produces both electricity and process steam(or heating energy, hereinafter expressed by process steam only). However, most of the models are not sufficiently accurate due to the wrong evaluation of the process steam value. The study suggests Electricity Conversion Efficiency (ECE) model with determination of the heat rate of process steam using operational data. The suggested method is applied to the design data and the resulted trajectory curve of power generation efficiency meets the data closely with R2 99.91%. This result confirms that ECE model with determination of the model coefficient using the operational data estimate the efficiency so accurately that can be used for performance monitoring of CHP plant.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.21 no.6
• /
• pp.65-70
• /
• 2021

Recently, as the number of mobile apps rapidly increases, the memory size of smartphones keeps increasing. Smartphone memory consists of DRAM and as it is a volatile medium, continuous refresh operations for all cells should be performed to maintain the contents. Thus, the power consumption of memory increases in proportion to the DRAM size of the system. There are attempts to configure the memory system with low-power non-volatile memory instead of DRAM to reduce the power consumption of smartphones. However, non-volatile memory has weaknesses in write operations, so analysis of write behaviors is a prerequisite to realize this in practical systems. In this paper, we extract memory reference traces of mobile apps and analyze their characteristics specially focusing on write operations. The results of this paper will be helpful in the design of memory management systems consisting of non-volatile memory in future smartphones.

• Journal of Convergence for Information Technology
• /
• v.9 no.3
• /
• pp.16-21
• /
• 2019

Small and medium-sized Korean companies are currently changing their industrial structure faster than in the past due to various environmental factors (such as securing competitiveness and developing excellent products). In particular, the importance of collecting and utilizing data produced in smart factory environments is increasing as diverse devices related to artificial intelligence are put into manufacturing sites. This paper proposes an artificial intelligence-based smart factory model to improve the process of products produced at the manufacturing site with the recent smart factory. The proposed model aims to ensure the increasingly competitive manufacturing environment and minimize production costs. The proposed model is managed by considering not only information on products produced at the site of smart factory based on artificial intelligence, but also labour force consumed in the production of products, working hours and operating plant machinery. In addition, data produced in the proposed model can be linked with similar companies and share information, enabling strategic cooperation between enterprises in manufacturing site operations.

• KIPS Transactions on Software and Data Engineering
• /
• v.8 no.7
• /
• pp.303-310
• /
• 2019

In the current mobile environment that is indispensable to our everyday lives, various forms of new business models are created including personalized services such as Google's "Google NOW" and Apple's "Siri". These services would not have been possible without technologies on the effective integration of various services and models. The requirements for effective integration of services include, 1) the efficient data sharing among multiple services, 2) the data-driven asynchronous execution of services, and 3) the simple extensible interaction method for the services. In this paper, we propose a mobile service architecture that utilizes the blackboard architecture to satisfy the aforementioned requirements to enable effective integration of various services, sharing and management of data between services, and asynchronous execution of services.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.22 no.3
• /
• pp.565-573
• /
• 2012

To investigate the business corruption, the obtainments of the business data such as personnel, manufacture, accounting and distribution etc., is absolutely necessary. Futhermore, the investigator should have the systematic extraction solution from the business data of the enterprise database, because most company manage each business data through the distributed database system, In the general business environment, the database exists in the system with upper layer application and big size file server. Besides, original resource data which input by user are distributed and stored in one or more table following the normalized rule. The earlier researches of the database structure analysis mainly handled the table relation for database's optimization and visualization. But, in the point of the digital forensic, the data, itself analysis is more important than the table relation. This paper suggests the extraction technique from the table relation which already defined in the database. Moreover, by the systematic analysis process based on the domain knowledge, analyzes the original business data structure stored in the database and proposes the solution to extract table which is related incident.

• The Journal of Korean Institute of Information Technology
• /
• v.17 no.11
• /
• pp.17-26
• /
• 2019

RAID-5 technology is one of the choice for flash storage device to enhance its reliability. However, RAID-5 has inherent parity update overhead, especially, parity overhead for partial stripe write is one of the crucial issues for flash-based RAID-5 technologies. In this paper, we design efficient parity log architecture for RAID-5 to eliminate runtime partial parity overhead. During runtime, partial parity is retained in buffer memory until full stripe write completed, and the parity is written with full strip write. In addition, parity log is maintained in memory until whole the stripe group is used for data write. With this parity log, partial parity can be recovered from the power loss. In the experiments, the parity log method can eliminate partial parity writes overhead with a little parity log writes. Hence it can reduce write amplification at the same reliability.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.30 no.6
• /
• pp.1279-1289
• /
• 2020

To securely protect users' sensitive information and national secrets, the importance of cryptographic modules has been emphasized. Currently, many companies and national organizations are actively using cryptographic modules. In Korea, To ensure the security of these cryptographic modules, the cryptographic module has been verified through the Korea Certificate Module Validation Program(KCMVP). Most of the domestic cryptographic modules are CPU-based software (S/W). However, CPU-based cryptographic modules are difficult to use in servers that need to process large amounts of data. In this paper, we propose an S/W cryptographic module that provides a high-speed operation using GPU. We describe the configuration and operation of the S/W cryptographic module using GPU and present the changes in the cryptographic module security requirements by using GPU. In addition, we present the performance improvement compared to the existing CPU S/W cryptographic module. The results of this paper can be used for cryptographic modules that provide cryptography in servers that manage IoT (Internet of Things) or provide cloud computing.

• Journal of the Korea Society of Computer and Information
• /
• v.27 no.7
• /
• pp.75-82
• /
• 2022

There are various exhibition halls, shopping malls, theme parks around us and analysis of interest in exhibits or contents is mainly done through questionnaires. These questionnaires are mainly depend on the subjective memory of the person being investigated, resulting in incorrect statistical results. Therefore, it is possible to identify an exhibition space with low interest by tracking the movement and counting the number of visitors. Based on this, it can be used as quantitative data for exhibits that need replacement. In this paper, we use deep learning-based artificial intelligence algorithms to recognize visitors, assign IDs to the recognized visitors, and continuously track them to identify the movement path. When visitors pass the counting line, the system is designed to count the number and transmit data to the server for integrated management.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.17 no.5
• /
• pp.949-958
• /
• 2022

Modern people have many kinds of clothes for individuals, and not just for storing clothes, but also for managing the condition of the closet, and users of smart closets created smart closets that provide daily convenience and optimal closet conditions, suggesting the possibility of developing smart furniture for various environments. In this developed system, smart closet is controlled using app inventor and touch LCD through bluetooth wireless communication, based on Arduino MEGA and user's clothes is recommended depending on the weather. In addition, this smart closet is designed with real-time weather status checking and easy ventilation function. It was implemented through the Arduino and app inventor program so that the weather can be printed on the LCD screen and the user's suitable clothes can be recommended to the application.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.25 no.2
• /
• pp.87-99
• /
• 2023

Ground excavation inevitably causes ground displacement of adjacent ground, and structures and facilities exposed to ground displacement may suffer various damages. Therefore, in order to minimize the damage and damage to adjacent structures and facilities caused by excavation, ground displacement (settlement and horizontal displacement) in the adjacent ground caused by excavation must first be predicted. There is many ground displacement information induced by general braced cut excavation, but the information is not enough for circular shaft excavation. This study aims to provide information on the estimation of ground settlement caused by circular shaft excavation through the case analysis of circular shafts and comparison with braced cut excavation. From this study, it was found that the use of the settlement criterion of braced cut excavation as the settlement management criterion for circular shaft excavation is a conservative approach in terms of safety. But when considering the economic aspect, it may result in overdesign of the wall and therefore, a more reasonable settlement criterion can be needed for circular shaft excavation.