• BMB Reports
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• v.42 no.2
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• pp.65-71
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• 2009

Autophagy, which is a process of self eating, has gained interest in the past decade due to its both beneficial and controversial roles in various biological phenomena. The discovery of autophagy genes (ATG) in yeast has led to focused research designed to elucidate the mechanism and regulation of this process. The role of autophagy in a variety of biological phenomena, including human disease, is still the subject of debate. However, recent findings suggest that autophagy is a highly regulated process with both beneficial and negative effects. Indeed, studies conducted using various model organisms have demonstrated that increased autophagy leads to an extended lifespan. Despite these findings, it is still unknown if all pathways leading to extended lifespan converge at the process of autophagy or not. Here, an overview of modern developments related to the process of autophagy, its regulation and the molecular machinery involved is presented. In addition, this review focuses on one of the beneficial aspects of autophagy, its role in lifespan regulation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.760-763
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• 2001

In this study, the graphical design system is developed and the digital mock-up is implemented for designing the spent fuel handling and disassembling processes. This system is used throughout the design stages from the conceptual design to the motion analysis. By using this system, all the processes involved in the spent fuel handling and disassembling precesses are analyzed and optimized. Also, this system is used in developing the on-line graphic simulator to enhance the reliability and safety of the spent fuel handling process by providing the remote monitoring function of the process. The graphical design system and the digital mock-up system can be effectively used for designing the process equipment, as well as the optimization of the main processes and maintenance processes of the spent fuel management.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.350-350
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• 2000

Since the heat exchange system, such as the boiler of power plant, gas turbine, and radiator require a high rate heat efficiency and the efficiency of these systems is depended on the control methods. However, it is important f3r operator to understand control system of these systems. In order to properly apply control equipment to these process control systems, such as boiler, any other heat process, or process control system it is necessary to understand the basic aspects and operation principle of the process that relate control, interrelationships of the process characteristics, and the dynamics that are involved. Generally, PID controllers are used in these systems but it is difficult for engineer to understand the complex dynamics and the tuning method because of the coupling action and disturbance in the system loop. In this paper, we design an effective experimental system fur automatic control education and analyze its characteristics through experimental system and industrial plant control software to study how they can team automatic control system by experiments.

• 한국IT서비스학회:학술대회논문집
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• 2005.11a
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• pp.356-365
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• 2005

Since their first inception a few decades ago, software components have received much attention mainly due to their alleged benefits of quality and productivity improvement. Despite this, it is yet to be agreed upon what and how components should be designed. This paper aimed to bridge the gap by proposing a collaborative process where the voice of the customer is captured and documented by employing the event and entity models. These requirement elements (WHAT) are cross-tabulated in three relation matrices in accordance with the weights provided by the business users. The requirements are fed into the algorithm invented by the authors to optimize the component grouping (HOW). This collaborative process has been successfully validated at an enterprise wide software development project. The process was effective to help the users more actively involved in the design of the system and made the whole process faster and more adaptive to the changes.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.4
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• pp.926-938
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• 1996

In this paper, we proposed a new multicast algorithm which is efficiently applicable to overlapped process group environments where one process may be involved in several process groups. Unlike the esisting algorithms, the proposed one provides an efficient group communication mechanism by generating the processgroup information in two-level tree. Using this algorithm, we improved the shortcoming of the existing algorithms by reducing the overhead in passing through unnecessary processes for message ordering. We have provided the causal ordering method as well as the total ordering method in group communication environments. As a result, we allow one process to deliver message to other processes with a short delay time, and reduced the overhead required for the message ordering. Also, we logically proved the proposed causal ordering method, and compared the performance of the proposed algorithm with ones of other existing algorithms by computer simulation.

• Biomolecules & Therapeutics
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• v.17 no.2
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• pp.113-124
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• 2009

Aging is a multifaceted biological process that affects all organs and organ systems of the body. This review provides an up-to-date analysis of this highly exciting, rapidly changing field of science. The aging process is largely under genetic control but is highly responsive to diverse environmental influences. The genes that control aging are those that are involved with cell maintenance, cell damage and repair. The environmental factors that accelerate aging are those that influence either damage of cellular macromolecules, or interfere with their repair. Prominent among these are chronic inflammation, chronic infection, some metallic chemicals, ultraviolet light, and others that heighten oxidative stress. Other environment factors slow the aging process. Included among these agents are resveratrol and vitamin D. In addition, dietary restriction and exercise have been found to extend human lifespan. The various mechanisms whereby all these agents exert their influence on aging include epigenetic modification, chromatin maintenance, protection of telomeres, and anti-oxidant defense, among others. The complex process of aging remains under continued, intense investigation.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.7
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• pp.163-170
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• 2004

In order to automatically determine the sequences of block assembly operations in shipbuilding, a process planning system using case-based reasoning (CBR) is developed. A block-assembly planning problem is modeled as a constraint satisfaction problem where the precedence relations between operations are considered constraints. The process planning system generates an assembly sequence by adapting information such as solutions and constraints collected from similar cases retrieved from the case base. In order to find similar cases, the process planning system first matches the parts of the problem and the parts of each case based on their roles in the assembly, and then it matches the relations related to the parts-pairs. The part involved in more operations are considered more important. The process planning system is applied to simple examples fur verification and comparison.

• Korean Journal of Computational Design and Engineering
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• v.11 no.2
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• pp.148-155
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• 2006

This paper presents a new method for assessing the efficiency of production process plans using tolerance chart to lower production cost. The tolerance chart is used to predict the accuracy of a part that is to be produced following the process plan, and to carry out the quantitative measurement on the efficiency of the process plan. By comparing the values of design tolerances and their corresponding resultant tolerances calculated using the tolerance chart, the process plan that is incapable of satisfying the design requirements and the faulty production operations can be identified. Similarly, the process plan that imposes unnecessarily high accuracy and wasteful production operations can also be identified. For the latter, a quantitative measure on the efficiency of the process plan is introduced. The higher the unnecessary cost of the production, the poor is the efficiency of the process plan. A coefficient is introduced for measuring the process plan efficiency. The coefficient also incorporates two weighting factors to reflect the difficulty of manufacturing operations and number of dimensional tolerances involved. To facilitate the identification of the machining operations and the machined surfaces, which are related to the unnecessarily tight resultant tolerances caused by the process plan, a rooted tree representation of the tolerance chart is introduced, and its use is demonstrated. An example is presented to illustrate the new method. This research introduces a new quantitative process plan evaluation method that may lead to the optimization of process plans.

• International Journal of Quality Innovation
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• v.7 no.1
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• pp.20-34
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• 2006

The purpose of this study is to investigate what happens within an organization when a process view of the business is adopted. With the example of an empirical case, we aim to illustrate: how members of the organization make sense of process management; what contributions members of the organization consider to be the result of adopting a process view; and the relationship between the functional and the process structure. The empirical base in this study is one of Sweden's largest purchasing organizations within the public sector. The results are drawn from interviews with the process owners and a survey to all members involved in process teams. The case findings reveal an ambiguous image of process management. At the same time as process management solved specific organizational problems, it generated new dilemmas. It is argued that it is more rewarding to consider the adoption of the process view a 'social negotiation' rather than the result of planned implementation. The study also highlights that the meaning of process management is not anything given but something being created, and its negotiation and translation into organizational practice is open-ended. Furthermore, the study gives an illustration of the conflict between the adopted process view and the existing functional organization.

• Journal of Microbiology and Biotechnology
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• v.15 no.5
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• pp.1060-1066
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• 2005

Under environmental stress, such as strong irradiance or nitrogen deficiency, unicellular green algae of the genus Haematococcus accumulate secondary carotenoids, i.e. astaxanthin, in the cytosol. The induction and regulation of astaxanthin biosynthesis in microalgae has recently received considerable attention owing to the increasing use of secondary carotenoids as a source of pigmentation for fish aquacultures, and as a potential drug in cancer prevention as a free-radical quencher. Accordingly, this study generated expressed sequence tags (ESTs) from a library constructed from astaxanthin-induced Haematococcus pluvialis. Partial sequences were obtained from the 5' ends of 1,858 individual cDNAs, and then grouped into 1,025 non-overlapping sequences, among which 708 sequences were singletons, while the remainder fell into 317 clusters. Approximately $63\%$ of the EST sequences showed similarity to previously described sequences in public databases. H. pluvialis was found to consist of a relatively high percentage of genes involved in genetic information processing ($15\%$) and metabolism ($11\%$), whereas a relatively low percentage of sequences was involved in the signal transduction ($3\%$), structure ($2\%$), and environmental information process ($3\%$). In addition, a relatively large fraction of H. pluvialis sequences was classified as genes involved in photosynthesis ($9\%$) and cellular process ($9\%$). Based on this EST analysis, the full-length cDNA sequence for superoxide dismutase (SOD) of H. pluvialis was cloned, and the expression of this gene was investigated. The abundance of SOD changed substantially in response to different culture conditions, indicating the possible regulation of this gene in H. pluvialis.