• Journal of Ecology and Environment
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• v.41 no.2
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• pp.34-44
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• 2017

Background: Monitoring terrestrial vegetation cover condition is important to evaluate its current condition and to identify potential vulnerabilities. Due to simplicity and low cost, point intercept method has been widely used in evaluating grassland surface and quantifying cover conditions. Field-based digital photography method is gaining popularity for the purpose of cover estimate, as it can reduce field time and enable additional analysis in the future. However, the caveats and uncertainty among field-based vegetation cover estimation methods is not well known, especially across a wide range of cover conditions. We compared cover estimates from point intercept and digital photography methods with varying sampling intensities (25, 49, and 100 points within an image), across 61 transects in typical steppe, forest steppe, and desert steppe in central Mongolia. We classified three photosynthetic groups of cover important to grassland ecosystem functioning: photosynthetic vegetation, non-photosynthetic vegetation, and bare soil. We also acquired normalized difference vegetation index from satellite image comparison with the field-based cover. Results: Photosynthetic vegetation estimates by point intercept method were correlated with normalized difference vegetation index, with improvement when non-photosynthetic vegetation was combined. For digital photography method, photosynthetic and non-photosynthetic vegetation estimates showed no correlation with normalized difference vegetation index, but combining of both showed moderate and significant correlation, which slightly increased with greater sampling intensity. Conclusions: Results imply that varying greenness is playing an important role in classification accuracy confusion. We suggest adopting measures to reduce observer bias and better distinguishing greenness levels in combination with multispectral indices to improve estimates on dry matter.

• Journal of the Korean Data and Information Science Society
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• v.24 no.4
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• pp.793-802
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• 2013

There are many problems to single sports talents out of test applicants. The physical activity promotion system has been performed to all elements school students of both 5 and 6 grades in order to evaluate overall health and physical activities since 2009. This system includes some variables which could measure the students' sports latent power, so that the system could be used to single out sports talents. In this work, we propose a primary screening method that element school teachers might evaluate sports talents based on the data of the physical activity promotion system. Two more sports talent indices which are sports flexibility index and sports endurance index are defined. The selection method of sports talents is developed by using sports latent indices including sports power and cardiorespiratory indices. This method is efficient from the view of time and cost aspects, since we do not need to remeasure all elements school students again.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.6
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• pp.857-870
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• 2017

The use of shield TBM is gradually increasing due to the urbanization of social infrastructures. Reliable estimation of advance rate is very important for accurate construction period and cost. For this purpose, it is required to develop the prediction model of advance rate that can consider the ground properties reasonably. Based on the database collected from field, statistical prediction procedure for field penetration index (FPI) was modularized in this study to calculate penetration rate of shield TBM. As output parameter, FPI was selected and various systems were included in this module such as, procedure of eliminating abnormal dataset, preprocessing of dataset and ridge regression with best subset selection. And it was finally validated by using field dataset.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.6
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• pp.843-851
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• 2009

Much work has already been done to control and regulate the worldwide problems caused by climate change, particularly the issues on greenhouse gas (GHG) emissions. Carbon dioxide ($CO_2$), having the highest form of concentration among GHGs composed around 1.0 billion tons of emission, and comprises about 98% of the total emissions from the shipping industry. Korean trade mainly rely on the sea transportation. Korean ship tonnages that was brought about by shipbuilders all over the country, continues to grow annually due to the prevailing demands on goods or material supplies and depicting only a small part of the global maritime activity. Nowadays, new build ships coming from the Korean Shipbuilders are being optimized by hull, structure and appendages design, The operational capability of the propulsion and auxiliary machineries in its maximum capacity to achieve the highest possible efficiencies for energy and onboard power use to mitigate $CO_2$ emissions are continually being done through the help of research and development. In this paper, the energy efficiency design index and anboard power capacity of Korean new build ships have been analyzed with response to data collected by ship types, and its respective fuel consumption in relation to $CO_2$ emission results. In response to climate change convention outcome proposals, the best way for the new build ships to become energy efficient is by lowering its operational speed thru adopting the state of the art diesel propulsion engines, patronizing the best sailing practice to lower the transportation cost on the different sea trade routes also helps in $CO_2$ mitigation.

• Journal of the Society of Disaster Information
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• v.8 no.4
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• pp.336-346
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• 2012

In recent years, the number of unforeseen weather hazards increased significantly, and subsequent financial loss in public and private sector has increased as well. Research has been increasingly focused on the actual damage assessment in the event of a disaster through effective and comprehensive disaster countermeasures to deal with and improve a better anti-disaster strategy. Through investigation of existing domestic and foreign property loss related to current damage analysis, the comparison and analysis in terms of current estimated methodology of the full extent of the damage results is proposed. In this study, a more efficient damage index and natural disaster damage assessment is suggested and more specifically, the basic standards of declared disaster areas and the strength of private property damage index will be also be discussed.

• KIISE Transactions on Computing Practices
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• v.22 no.5
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• pp.225-234
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• 2016

The emergence of diverse medical Internet of Things (IoT) devices has facilitated the collection and analysis of medical contexts to assess health conditions. However, the complexity of IoT-based systems for health assessment is quiet high and it requires high development cost, since the designs of the systems highly depend on the heath aspects to be evaluated. In this paper, we propose a design of the platform that provides generic functionalities to various health evaluation applications. We first define a metric for computing a health index, which is a generic health assessment model. And, based on the proposed generic health index, we propose a design of the platform to evaluate diverse aspects of the health including its hardware architecture, software architecture and database design. We describe the result of developing Rainbow Toilet System based on the proposed platform, and assess the practical applicability.

• The KIPS Transactions:PartA
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• v.15A no.6
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• pp.325-334
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• 2008

Flash memory is widely used as a storage medium for mobile devices such as cell phones, MP3 players, PDA's due to its tiny size, low power consumption and shock resistant characteristics. Additionally, some computer manufacturers try to replace hard-disk drives used in Laptops or personal computers with flash memory. More recently, there are some literatures on developing a flash memory-aware $B^+$-tree index for an efficient key-based search in the flash memory storage system. They focus on minimizing the number of "overwrites" resulting from inserting or deleting a sequence of key values to/from the $B^+$-tree. However, in addition to this factor, the size of a physical page allocated to a node can affect the maintenance cost of the $B^+$-tree. In this paper, with diverse experiments, we compare and analyze the costs of construction and search of the $B^+$-tree and the space requirement on flash memory as the node size increases. We also provide sorting-based or non-sorting-based algorithms to be used when inserting a key value into the node and suggest an header structure of the index node for searching a given key inside it efficiently.

• The KIPS Transactions:PartD
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• v.10D no.2
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• pp.175-186
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• 2003

Mobile clients like a PDA need a cache and a spatial index to search and access map data efficiently. When a server transmits spatial objects to a mobile client which has a low storage capacity, some of them can be duplicated in a cache of the mobile client. Moreover, the cost for strong added data in the cache and reconfiguring spatial index is very high in the mobile client with low computing power. The scheme for processing duplicated objects and disturbing tasks of the mobile client which has low computing power is needed. In this paper, we classfy the method for strorng duplicated objects and present the scheme for the both caching objects and reconfiguring a spatial index of cached objects using the clipping technique. We propose the caching system based on an agent in order to distribute the overhead of a mobile client as well as to provide efficiently map services. We design and implement it, and evaluate the performance.

• Journal of the Korean Society for Railway
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• v.15 no.3
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• pp.272-277
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• 2012

KORAIL's logistics business coefficient is improved slightly from 197.4 in 2009 to 190.7 in 2010 but the cost is still high compared to the revenues. In order to derive activities for the efficient logistics and measure their effects quantitatively, the analysis of various indexes that can be extracted from the statistical data is very important. In this study, the various indexes are analyzed to evaluate the efficiency of freight cars based on railway logistics. It can be used to estimate the various activities for the efficient logistics associated with freight cars. We suggest the Indexes as the number of transport, cumulative transport distance and transport income to evaluate the efficiency of freight cars and they should be applied according to the characteristics of each index.

• Safety and Health at Work
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• v.10 no.2
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• pp.219-223
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• 2019

Background: Ice cooling vests can cause tissue damage and have no flexibility. Therefore, these two undesirable properties of ice cooling vest were optimized, and the present study was aimed to compare the impact of the optimized ice cooling vest and a commercial paraffin cooling vest on physiological and perceptual strain under controlled conditions. Methods: For optimizing, hydrogel was used to increase the flexibility and a layer of the ethylene vinyl acetate foam was placed into the inside layer of packs to prevent tissue damage. Then, 15 men with an optimized ice cooling vest, with a commercial paraffin cooling vest, and without a cooling vest performed tests including exercise on a treadmill (speed of 2.8 km/hr and slope of %0) under hot ($40^{\circ}C$) and dry (40 %) condition for 60 min. The physiological strain index and skin temperature were measured every 5 and 15 minutes, respectively. The heat strain score index and perceptual strain index were also assessed every 15 minutes. Results: The mean values of the physiological and perceptual indices differed significantly between exercise with and without cooling vests (P < 0.05). However, the difference of the mean values of the indices except the value of the skin temperature during the exercises with the commercial paraffin cooling vest and the optimized ice cooling vest was not significant (P > 0.05). Conclusions: The optimized ice cooling vest was as effective as the commercial paraffin cooling vest to control the thermal strain. However, ice has a greater latent heat and less production cost.