• FOCUS: LIFE SCIENCE
• /
• no.1
• /
• pp.1.1-1.4
• /
• 2024

This article provides comprehensive guidance on the maintenance, cleaning, regeneration, and storage of silica-based HPLC (High-Performance Liquid Chromatography) columns. The general considerations emphasize the importance of using in-line filters and guard cartridges to protect columns from blockage and irreversible sample adsorption. While these measures help, contamination by strongly adsorbed sample components can still occur over time, leading to an increase in back pressure, loss of efficiency, and other issues. To maximize column lifetime, especially with UHPLC (Ultra-High Performance Liquid Chromatography) columns, it is advisable to use ultra-pure solvents, freshly prepared aqueous mobile phases, and to filter all samples, standards, and mobile phases. Additionally, an in-line filter system and sample clean-up on dirty samples are recommended. However, in cases of irreversible compound adsorption or column voiding, regeneration may not be possible. The document also provides specific recommendations for column cleaning procedures, including the flushing procedures for various types of columns such as reversed phase, unbonded silica, bonded normal phase, anion exchange, cation exchange, and size exclusion columns for proteins. The flushing procedures involve using specific solvents in a series to clean and regenerate the columns. It is emphasized that the flow rate during flushing should not exceed the specified limit for the particular column, and the last solvent used should be compatible with the mobile phase. Furthermore, the article outlines the storage conditions for silica based HPLC columns, highlighting the impact of storage conditions on the column's lifetime. It is recommended to flush all buffers, salts, and ion-pairing reagents from the column before storage. The storage solvent should ideally match the one used in the initial column test chromatogram provided by the manufacturer, and column end plugs should be fitted to prevent solvent evaporation and drying out of the packing bed.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.7 no.4
• /
• pp.923-948
• /
• 2013

The main concern in mobile peer-to-peer (P2P) networks is security because jamming or eavesdropping on a wireless link is much easier than on a wired one and such damage can be incurred without physical access or contact. In particular, authentication has increasingly become a requirement in mobile P2P environments. This paper presents a new mutual authentication mechanism which requires less storage space and maintains a high level of security in mobile P2P networks. The proposed mechanism improves efficiency by avoiding the use of centralized entities and is designed to be agile in terms of both reliability and low-cost implementation. The mechanism suggested in the simulation evaluates the function costs occurring in authentication between the devices under mobile P2P network environment comparing to existing method in terms of basic operation costs, traffic costs, communications costs, storage costs and scalability. The simulation results show that the proposed mechanism provides high authentication with low cryptography processing overhead.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.6 no.6
• /
• pp.1689-1706
• /
• 2012

The preservation of temporal dependencies among a group of processes that exchange continuous media at runtime is a key issue for emerging mobile distributed systems (MDS), such as monitoring of biosignals and interactive multiuser games. Although several works are oriented to satisfy temporal dependencies, most of them are not suitable for MDSs. In general, an MDS is characterized by the absence of global references (e.g. shared memory and wall clock), host mobility, limited processing and storage capabilities in mobile hosts, and limited bandwidth on wireless communication channels. This paper proposes an asymmetric synchronization protocol to be used at runtime in an MDS without using a common reference. One main aspect of our synchronization protocol is that it translates temporal constraints to causal dependencies of the continuous media data as seen by the mobile hosts. We simulate the protocol by considering a cellular network environment and by using MPEG-4 encoders. The simulation results show that our protocol is effective in reducing the synchronization error. In addition, the protocol is efficient in terms of processing and storage costs at the mobile devices, as well as in the overhead attached per message across the wired and wireless channels.

• International journal of advanced smart convergence
• /
• v.8 no.1
• /
• pp.9-17
• /
• 2019

In this article, we present a performance enhancement scheme for mobile applications by adopting persistent memory. The proposed scheme supports the deadline guarantee of real-time applications like a video player, and also provides reasonable performances for non-real-time applications. To do so, we analyze the program execution path of mobile software platforms and find two sources of unpredictable time delays that make the deadline-guarantee of real-time applications difficult. The first is the irregular activation of garbage collection in flash storage and the second is the blocking and time-slice based scheduling used in mobile platforms. We resolve these two issues by adopting high performance persistent memory as the storage of real-time applications. By maintaining real-time applications and their data in persistent memory, I/O latency can become predictable because persistent memory does not need garbage collection. Also, we present a new scheduler that exclusively allocates a processor core to a real-time application. Although processor cycles can be wasted while a real-time application performs I/O, we depict that the processor utilization is not degraded significantly due to the acceleration of I/O by adopting persistent memory. Simulation experiments show that the proposed scheme improves the deadline misses of real-time applications by 90% in comparison with the legacy I/O scheme used in mobile systems.

• The KIPS Transactions:PartD
• /
• v.15D no.6
• /
• pp.733-740
• /
• 2008

Recently, mobile computing devices are used popularly. And quantity of information on mobile computing devices is being increased due to digitalization of information. So it needs an embedded DBMS for effective information management. Furthermore, since flash memory having a restriction on the number of partial write cycles is rapidly deployed on mobile computing devices as data storage and is more expensive than the conventional magnetic hard disk, the compressed data management system(CDMS) has been considered as an effective storage management technique for mobile computing devices in previous research. However, the research of CDMS is at the initial stage and has several problems. Hence, in this paper, we present additional storage management methods to solve the problems and improve the effectiveness of the CDMS for embedded DBMS.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.4
• /
• pp.536-543
• /
• 2017

This study developed a new methodology to evaluate the carbon storage using a Mobile Mapping System according to the life cycle of street trees. The system for calculating the carbon storage of a roadside tree using the MMS developed in this study consisted of a database, memory, processor, user interface, and communication module. The carbon storage was calculated for 261 trees in the Cheonan-Asan New Town (distance: 2.1 km, area: $283,698m^2$). The average biomass and carbon storage of Metasequoia glyptostroboides were highest at 34.5 kg and 17.3 kg C and Chionanthus retusa were lowest at 19.5 kg and 9.8 kg C, respectively. The total biomass and total carbon storage of Ginkgo biloba were highest at 5028.8 kg and 17.3 kg C and Chionanthus retusa were lowest at 780.7 kg and 390.3 kg C, respectively. Based on the roadside tree database, the amount of carbon storage in a given area was converted to Google format and visualized in 3D by GIS analysis.

• The Journal of Society for e-Business Studies
• /
• v.15 no.4
• /
• pp.21-31
• /
• 2010

Recently e-business such as online financial trade and online shopping using mobile computes are widely spread. Most of mobile computers use NAND flash memory-based storage devices for storing data. Flash memory storage devices use a software called flash translation layer to translate logical address from a file system to physical address of flash memory by using mapping tables. The legacy FTLs have a problem that they must maintain very large mapping tables in the RAM. In order to address this issues, in this paper, we proposed a new caching scheme of mapping tables. We showed through the trace-driven simulations that the proposed caching scheme reduces the space overhead dramatically but does not increase the time overhead. In the case of online transaction workload in e-business environment, in particular, the proposed scheme manifests better performance in reducing the space overhead.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2022.10a
• /
• pp.594-596
• /
• 2022

This paper relates to a system for pre-processing high-definition images acquired through a camera mounted on an unmanned aerial vehicle(UAV) and transmitting them to a server through a mobile communication network. In the case of the existing UAV system for image acquisition service, the acquired image was stored in the external storage device of the camera mounted on the UAV, and the image was checked by directly moving the storage device after the flight was completed. In the case of this method, there is a limitation in that it is impossible to check whether image acquisition or pre-processing is properly performed before directly checking image data through an external storage device. In addition, since the data is stored only in an external storage device, there is a disadvantage that data sharing is cumbersome. In this paper, to solve the above problems, we propose a system that can remotely check images in real time. Furthermore, we propose a system and method capable of performing pre-processing such as geo-tagging and transmission through a mobile communication network in addition to image acquisition through shooting in an UAV.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.8 no.1
• /
• pp.99-105
• /
• 2012

Given the numbers of smartphones, tablets and other mobile devices shipped every day, more and more users are relying on the cloud as the main driver for satisfying their computing needs, whether it is data storage, applications or infrastructure. Mobile cloud computing is simply cloud computing in which at least some of the devices involved are mobile. Each node is owned by a different user and is likely to be mobile. Using mobile hardware for cloud computing has advantages over using traditional hardware. These advantage include computational access to multimedia and sensor data without the need for large network transfer, more efficient access to data stored on other mobile devices and distributed ownership and maintenance of hardware. It is important to predict job execution time in mobile cloud computing because there are many mobile nodes with different capabilities. This paper analyzes the job execution time for mobile cloud computing in terms of network environment and heterogeneous mobile nodes using a mathematical model.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2015.10a
• /
• pp.251-252
• /
• 2015

Recently, as warehouses became automated, workers are trying to maximize storage efficiency as well as work efficiency. So, using mobile-rack which has wheels or rails at the bottom and minimizes dead space by removing extra passages between racks is rapidly rising as a notable technology. So, this paper seeks how to manage optimally cryogenic warehouse using mobile-rack. At first, routes of mobile-rack and operation vehicle will be synchronized and storage location will be decided with seasonal demand. After that, it will be simulated considering additional factors.