• Journal of Power System Engineering
• /
• v.10 no.4
• /
• pp.105-110
• /
• 2006

Among many other alternative energy resources, small scale hydro power has been brought into attention as a reliable source of energy today, which had been relatively neglected since 1960s. Especially, Kaplan micro-turbine can be applied to various kind of small hydro power plants, such as reservoirs for agriculture purpose, sewage treatment plants and water purification plants. However present low head of Kaplan micro-turbines and small scale hydro turbines, have limitations in the minimum required head and flow rate for efficient operation. This research is to develop modeling analysis for the Kaplan micro-turbine, which can improve economical features of small hydro power plants. The contents and scope of this research are the efficiency improvement of Kaplan micro-turbine.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.20 no.1
• /
• pp.57-64
• /
• 2008

Recently, regulation of ventilator installation and its details has been revised and the establishment of heat recovery ventilator in newly built apartments has been obligated. This study was done to offer the method of operation and design of heat recovery ventilator to save energy by measuring its efficiency and comparing with the results of experiment. This paper confirmed that it is desirable to operate heat recovery ventilator by using "by-pass mode" within $60{\sim}80%$ scope of the difference indoor absolute humidity in spring and autumn and outdoor absolute humidity and heat recovery ventilator of energy saving effect is better than constant air volume system.

• International journal of advanced smart convergence
• /
• v.11 no.3
• /
• pp.72-78
• /
• 2022

The aim of this research is to improve the effectiveness of digital media advertising because current advertisements -in digital signage - indiscriminately appeals to the general public rather than to a specific target. In order to deliver efficient and customized advertisement information, an IoT human body detection sensor mounted on digital signage detected human faces and then classified them firstly by gender. The digital signage here is a smart digital signage that can analyze facial signals, discriminate them based on patterns, and apply the extracted data by displaying the corresponding information to the user. In addition, by identifying the customer's location approaching the smart digital signage and displaying the optimized content information for the customer's location through an algorithm, the digital signage can dramatize the advertisement Thus, this is a study meant forimproving information efficiency while reducing noise and driving power waste generated from unnecessary digital information reproduction.

• Journal of Applied Biological Chemistry
• /
• v.66
• /
• pp.512-518
• /
• 2023

To address inherent weaknesses such as low mechanical strength and limited enzyme loading capacity in conventional chitosan or alginate beads, an additional step involving the exchange of anionic surfactants with hydroxide ions was employed to prepare porous chitosan hydrogel capsules for enzyme immobilization. Consequently, excellent thermal stability and long-term storage stability were confirmed. Furthermore, coating the porous chitosan hydrogel capsules with polydopamine not only improved mechanical stability but also exhibited remarkable enzyme immobilization efficiency (97.6% for M1-D0.5). Additionally, it was demonstrated that the scope of application for chitosan hydrogel beads, prepared using conventional methods, could be further expanded by introducing an additional step of polydopamine coating. The enzyme immobilization matrix developed in this study can be selectively applied to suit specific purposes and is expected to be utilized as a support for the adsorption or covalent binding of various substances.

• Clinical Endoscopy
• /
• v.55 no.6
• /
• pp.726-735
• /
• 2022

Inflammatory bowel disease (IBD) has a global presence with rapidly increasing incidence and prevalence. Patients with IBD including those with ulcerative colitis and Crohn's disease have a higher risk of developing colorectal cancer (CRC) compared to the general population. Risk factors for CRC in patients with IBD include long disease duration, extensive colitis, primary sclerosing cholangitis, family history of CRC, stricture, and prior dysplasia. Surveillance colonoscopy for CRC in patients with IBD should be tailored to individualized risk factors and requires careful monitoring every year to every five years. The current surveillance techniques are based on several guidelines. Chromoendoscopy with targeted biopsy is being recommended increasingly, and high-definition colonoscopy is gradually replacing standard-definition colonoscopy. However, it remains unclear whether chromoendoscopy, virtual chromoendoscopy, or white-light endoscopy has better efficiency when a high-definition scope is used. With the development of new endoscopic instruments and techniques, the paradigm of surveillance strategy has gradually changed. In this review, we discuss cutting-edge surveillance colonoscopy in patients with IBD including a review of literature.

• Applied Chemistry for Engineering
• /
• v.16 no.1
• /
• pp.74-80
• /
• 2005

The effective removal of turbid-inducing particulates and algae-inducing phosphorous was systematically investigated by the variation of physico-chemical parameters such as pH, alkalinity, and coagulant types. Al(III)-based and Fe(III)-based coagulants exhibited high removal efficiency of turbidity and phosphorous at optimal pH ranges of 7~9, in which zeta potential nearly approached to zero. The removal rate of turbidity rapidly increased with the increase of coagulant dosages, whereas the removal rate of phosphorous gradually increased due to an equivalent reaction of phosphorous with metallic ions. The generation of flocs during coagulation was visualized by high speed camera (Motion Scope 2000, Redlake Co.), and the images of singular flocs were captured by optical microscope. The flocs generated by Fe(III)-based coagulant was more compact than those induced by Al(III)-based coagulant, and the settlabiltiy of Fe(III)-induced flocs was superior to that of Al(III)-induced flocs.

• Journal of Korean Society for Atmospheric Environment
• /
• v.33 no.4
• /
• pp.393-402
• /
• 2017

In this study, greenhouse gas (GHG) reductions from bioenergy (biogas, biomass) have been estimated in Korea, 2015. This study for construction of reduction inventories as direct and indirect reduction sources was derived from IPCC 2006 guidelines for national greenhouse gas inventories, guidelines for local government greenhouse inventories published in 2016, also purchased electricity and steam indirect emission factors obtained from KPX, GIR respectively. As a result, the annual GHG reductions were estimated as $1,860,000tonCO_{2eq}$ accounting for 76.8% of direct reduction (scope 1) and 23.2% of indirect reduction (scope 2). Estimation of individual greenhouse gases (GHGs) from biogas appeared that $CO_2$, $CH_4$, $N_2O$ were $90,000tonCO_2$ (5.5%), $55,000tonCH_4$ (94.5%), $0.3tonN_2O$ (0.004%), respectively. In addition, biomass was $250,000tonCO_2$ (107%), $-300tonCH_4$ (-3.2%), $-33tonN_2O$ (-3.9%). For understanding the values of estimation method levels, field data (this study) appeared to be approximately 85.47% compared to installed capacity. In details, biogas and biomass resulting from field data showed to be 76%, 74% compared to installed capacity, respectively. In the comparison of this study and CDM project with GHG reduction unit per year installed capacity, this study showed as 42% level versus CDM project. Scenario analysis of GHG reductions potential from bioenergy was analyzed that generation efficiency, availability and cumulative distribution were significantly effective on reducing GHG.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.21 no.11
• /
• pp.2167-2175
• /
• 2017

In recent years, an IoT is dramatically developing according to the enhancement of AI, the increase of connected devices, and the high-performance cloud systems. Huge data produced by many devices and sensors is expanding the scope of services, such as an intelligent diagnostics, a recommendation service, as well as a smart monitoring service. The studies of edge computing are limited as a role of small server system with high quality HW resources. However, there are specialized requirements in a smart factory domain needed edge computing. The edges are needed to pre-process containing tiny filtering, pre-formatting, as well as merging of group contexts and manage the regional rules. So, in this paper, we extract the features and requirements in a scope of efficiency and robustness. Our edge offers to decrease a network resource consumption and update rules and learning models. Moreover, we propose architecture of edge computing based on learning factors sharing with a cloud system in a smart factory.

• International Journal of Highway Engineering
• /
• v.20 no.4
• /
• pp.73-84
• /
• 2018

PURPOSES : Most of the traffic surveys are carried out by an inspection method by the manpower. In some cases, the video equipment is used only in some regions when the traffic volume is surveyed. In this case, there is environmental restriction that the road equipment to fix the video equipment should exist. Also, in areas where information such as digital maps and satellite photographs is old or not provided, they are forced to rely on manpower research, but it is difficult to put huge amounts of time and money into the research in places where labor supply and demand is difficult. This difficulty is particularly pronounced in overseas business. METHODS : The purpose of this study is to improve the efficiency of business by using the drones in the traffic investigation through analysis of the cost reduction effect between the existing method and the proposed method in the overseas business traffic survey. The scope of the research is limited to the scope of research, and based on the case of overseas projects, the method of using drone for each research sector is suggested. RESULTS : In the traffic condition survey section, we propose the use of drone for traffic survey and queue length survey, and it is confirmed that there is a cost saving effect of 16% ~ 27% compared with the existing method. In the road condition survey, we propose the use of drones for road surface linear survey, geometry survey, and obstacle survey, and it was confirmed that the cost reduction effect is 39% ~ 93% compared to the existing method. CONCLUSIONS : In addition to overseas business, it is expected that it will have a positive effect on research time and cost reduction by using drone in traffic survey in domestic area where labor supply is not easy or basic data is insufficient.

• Health Policy and Management
• /
• v.16 no.4
• /
• pp.68-85
• /
• 2006

With the competitive environment accelerating in healthcare industry, the hospital network system is considered as one of the strategies for clinical and managerial efficiency. This study was intended to offer a theoretical view on the hospital network system and to analyze the current network status of hospitals in Korea. Specifically, network types were classified based on the criteria modified from previous studies, and were used to describe and compare the scope and intensity of associated activities. The questionnaire survey was conducted with 237 hospitals during the period of December 27 2005 to January 25 2006. Above 90% of tertiary and secondary care hospitals were under the network system, while only 20% of primary care clinics were affiliated. In general, the scope and intensity of network activities was limited. Vertical and/or clinical integration was more common than horizontal and/or managerial integration. Three most frequent types of hospital network systems were clinical-vertical integration (Type A), clinical/managerial-vertical integration(Type B), and clinical/managerial-horizontal /vertical integration (Type C). Such network types differentiated significantly different features of affiliated hospitals and network systems. The affiliation duration to the network system was the only significant factor influencing on the network type. The strategic approach to the network system was emphasized for hospitals to increase the potential advantage of hospital network systems.