• BMB Reports
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• v.51 no.11
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• pp.547-548
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• 2018

Phloem network integrates cellular energy status into post-embryonic growth, and development by tight regulation of carbon allocation. Phloem development involves complicated coordination of cell fate determination, cell division, and terminal differentiation into sieve elements (SEs), functional conduit. All of these processes must be tightly coordinated, for optimization of systemic connection between source supplies and sink demands throughout plant life cycle, that has substantial impact on crop productivity. Despite its pivotal role, surprisingly, regulatory mechanisms underlying phloem development have just begun to be explored, and we recently identified a novel translational regulatory network involving RNA G-quadruplex and a zinc-finger protein, JULGI, for phloem development. From this perspective, we further discuss the role of RNA G-quadruplex on post-transcriptional control of phloem regulators, as a potential interface integrating spatial information for asymmetric cell division, and phloem development.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.22 no.1
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• pp.108-113
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• 2014

Recently increase in the number of aircraft caused the air traffic congestion and flight delays. If timely action to reform the air traffic system is not taken, these may result in added economic impact. As a result, the air traffic management should be changed in an innovative manner to modernize the existing air traffic control environment. This paper reviews the trends of airspace reforms such as integration of terminal control areas and flexible use of airspace introduced by foreign countries and compares their merits and demerits in order to provide a judgement to adopt the concept in domestic airspace in the future.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.753-758
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• 2007

AHP analysis was carried out to derive the optimum mix weight of hydrogen energy production material presented in a "national vision of the hydrogen economy and the action plan" and aimed to be commercialized by $2030{\sim}2040$ year. Six kinds of hydrogen production materials(natural gas, spare electric energy, fleeting gas, renewable energy, coal, nuclear energy) was selected as subjects of study and the perspective of optimum mix weight was derived through AHP analysis.

• International Journal of Safety
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• v.11 no.1
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• pp.26-32
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• 2012

This paper introduces a feasibility evaluation method for prognosis systems based on an empirical model in nuclear power plants. By exploiting the dynamical signature characterized by abnormal phenomena, the prognosis technique can be applied to detect the plant abnormal states prior to an unexpected plant trip. Early $operator^{\circ}{\emptyset}s$ awareness can extend available time for operation action; therefore, unexpected plant trip and time-consuming maintenance can be reduced. For the practical application in nuclear power plant, it is important not only to enhance the advantages of prognosis systems, but also to quantify the negative impact in prognosis, e.g., uncertainty. In order to apply these prognosis systems to real nuclear power plants, it is necessary to conduct a feasibility evaluation; the evaluation consists of 4 steps (: the development of an evaluation method, the development of selection criteria for the abnormal state, acquisition and signal processing, and an evaluation experiment). In this paper, we introduce the feasibility evaluation method and propose further study points for applying prognosis systems from KHNP's experiences in testing some prognosis technologies available in the market.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.2
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• pp.330-336
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• 2011

RFID is the item is at the core of the Internet, promoting action in the online community is a pivotal element. RFID uses radio frequency waves to automatically find the technology to track individuals and items referring to the short-range wireless technology can be included. For example, ZigBee and Bluetooth has a strong ability to track and calculate. In this study, major advances in this technology by analyzing the techniques of intensive discussions, the current progress of mankind, and the impact on the future direction of development is included.

• Journal of Ocean Engineering and Technology
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• v.12 no.3 s.29
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• pp.9-18
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• 1998

An improved evaluation method of load-carrying capacity for the large-scaled offshore structures, which subjected to the axial force and bending moments simultaneously at the piles, was suggested with reliability analysis and advanced working stress method. Reliability analysis requires the fracture probability and safety factor(${beta}$) for each of forces and the load-carrying capacity due to combined action of axial force and bending moments from $P_n - {beta}$ Curve. The combined equation due to those forces, which suggested by the Korean Specification for the marine structure, was derived for the advanced working stress method and applied to evaluate the load-carrying capacity of jacket-type dolphin piers.

• The Journal of Information Technology and Database
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• v.8 no.1
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• pp.81-94
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• 2001

Providing explanations about recommending actions is one of the most important capabilities of expert systems. In fact, there exist many approaches incorporating this explanation facility into the system. Here we present briefly a new approach to generating these explanations and further attempt to investigate the impact of system explanations on user behaviors toward system-generated recommendations. For this experiment we designed a stock investment decision supporting system which, given a set of market situations, suggests an investment recommendation with explanations about the recommending action. Twenty-nine bank employees evaluated the output of the system in a laboratory setting. The results indicate that explanation facilities can make systems-generated advice more confident to users but cannot increase users'acceptance for the system conclusion.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.749-756
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• 2006

Because of the orthotropic elastic properties and significant two-way bending action, orthotropic plate theory may be suitable for describing the behavior of concrete filled grid bridge decks. Current AASHTO LRFD Bridge Design Specification(2004) has live load moment equations considering flexural rigidity ratio between longitudinal and transverse direction, but the Korea highway bridge design specification(2005) doesn't. The Korea highway bridge standard specification LRFD(1996) considers an orthotropic plate model with a single load to estimate live load moments in concrete filled grid bridge decks, which may not be conservative. This paper presents live load moment equations for truck and passenger car, based on orthotropic plate theory. The equations of truck model use multiple presence factor, impact factor, design truck and design tandem of the Korea highway bridge standard specification LRFD(1996). The estimated moments are verified through finite-element analyses.

• Journal of environmental and Sanitary engineering
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• v.20 no.4 s.58
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• pp.1-8
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• 2005

Pocheon is a basin geographically, and the diffusion of air pollutants is very difficult. Thus, it is essential to consider the characteristics of geographical and weather conditions before industrial complex and various air pollution sources are developed in the area. It is recommended that Environmental Impact Statements (EIS) must be carried out before any action is taken. Constantly occurring fog in the Pocheon area absorbs large amounts of acidic gases, and it transformed into the secondary pollutants such as the salts of sulfate and nitrate. Fog, which occurs very often in Pocheon area, was analyzed for its acid components. Conversion from the gaseous sulfur dioxide into sulfate ion is relatively high, $86\~90\%$ while $68\~76\%$ of NOx is converted into nitrate ion form.

• Steel and Composite Structures
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• v.7 no.2
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• pp.105-118
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• 2007

On September $11^{th}$ 2001, the twin towers of the World Trade Center in New York City were struck by two hijacked airplanes. Despite severe local damage induced by the impact, the towers were able to sustain 102 and 56 minutes of the subsequent multi-storey fires before collapsing. The purpose of this study is to contribute to the understanding of the in-fire performance of composite trusses by examining the behaviour of the longer-span type used in the towers. It makes no attempt to be a forensic study of the actual events. Using the finite element package Vulcan, the structural mechanics of typical long-span composite floor trusses are explained, under a variety of scenarios, as the fire temperatures rise. Different boundary conditions, degrees of protection and loading are all covered, the results being presented mainly in the form of graphs of deflection and internal force of members against time.