• Journal of the Korean GEO-environmental Society
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• v.13 no.6
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• pp.67-72
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• 2012

Finite element method was used to compare un-piled and piled raft foundation behaviors on sandy soils in this study. The soil parameters were estimated from SPT tests of 25 boreholes. Based on these soil parameters, a finite element analysis was conducted on un-piled and piled raft foundations. For the un-piled raft, the normalized settlement parameter for raft sizes of $8m{\times}8m$ and $15m{\times}15m$ ranged from 1.02~1.15 and 0.64~0.81, respectively. The raft thickness affects differential settlement and bending moments, but has little effect on load sharing or maximum settlement. Pile spacing greatly affected the maximum settlement, the differential settlement, the bending moment in the raft, and the load shared by the piles, while the differential settlement, the maximum bending moment and the load sharing are not affected very much by increasing the pile lengths.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.469-479
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• 2016

Kimchi cabbage is one of the most important vegetables in Korea and a target crop for market stabilization as well. In particular Kimchi cabbages in a highland area are very sensitive to the fluctuations in supply and demand. Yield variability due to growth conditions dictates the market fluctuations of Kimchi cabbage price. This study was carried out to understand the distribution of the highland Kimchi cabbage growth status in Anbandeok. Anbandeok area in Gangneung, Gangwon-do, Korea is one of the main producing districts of highland Kimchi cabbage. The highland Kimchi cabbage status map of each growth factor was obtained from unmanned aerial vehicle (UAV) imagery and field survey data. Six status maps include UAVRGB image map, normalized difference vegetation index (NDVI) distribution/anomaly map, Crop distribution map, Planting/Harvest distribution map, Growth parameter map and Growth disorder map. As a result, the highland Kimchi cabbage status maps from May 31 to Sep. 6 in 2016 were presented to show spatial variability in the field. The benefits of the highland Kimchi cabbage status map can be summarized as follows: crop growth monitoring, reference for field observations and survey, the relative comparison of the growth condition in field scale, evaluation of growth in comparison of average year, change detection of annual crops or planting areas, abandoned fields monitoring, prediction of harvest season etc.

• Journal of Environmental Science International
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• v.1 no.1
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• pp.47-51
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• 1992

Volatile organic rompounds(VOCs) present in the VOCs-contaminated water are released to air while showering and their air concentrations depend on the shower parameters, resulting in the variation of the VOCs breath concentration. The present study evaluated the key shower parameters(water temperature and inhalation duration) that affect the inhalation exposure to air chloroform while showering, by determining chloroform breath concentration. The chloroform breath concentrations increased with water temperature and inhalation duration increase. The two inhalation exposure conditions which resulted in the greatest chloroform breath contentration difference were a 5 min-inhalation exposure with warm water and a 15 min-inhalation exposure with hot water. The chloroform breath concentration was almost three times higher after later exposure. The mathematical model analyzing the relationship between two key shower parameters and breath concentration normalized to water concentration fits quite Ivell with the experimental data at a probability of p : 0.0001.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.4
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• pp.313-322
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• 2005

In this paper, High power factor electronic ballast using a double resonant Inverter for 250[W] MHD lamp is designed and implemented. Proposed electronic ballast is composed of configuration that is cascaded boost active PFC circuit as power factor corrector and half-bridge double resonant inverter Into two stage approach. Theoretical analysis of circuit and characteristics estimation is generally illustrated by using normalized parameter. To remove the phenomenon of acoustic resonance in the lamp, Simple frequency controller composed timer IC and driving IC is designed and employed on the ballast. The experimental results show that an high power factor electronic ballast using a double resonant inverter is operated stably.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.12
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• pp.2806-2818
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• 1997

It is generallyaccepted that broadband access technologies will play an important role in the National Information Infrastructure. However, the provision of direct fibers to residential and small business customers has always been considered a challenge. To accelerage the provision of Broadband Access Facilities, alternatibe paths could be identified and actaivated in parallel. In this paepr, we present an overview of the alternative access technologies focusing on xDSL, FTTx, HFC, HFR, and suggest the modeling of the access netetwork systems which is using of the technologies. Also to investigate the economics of each access systems, we derve the numerical equations which is summed up the al parameter including the labor cost of the model system. The proposed equation has a variable which is the cell size (or subsciber clusters) and calculate the real cost values which is normalized by the copper cable unit cost. From the numerical resutls, we conclude that the economic access method to provide these broadband capabilities is depended on the subscriber penetration, the patterns of subscriber distribution density and existing communication infrastructures. It can be expected that our analytical model and equations provides an elegant solution to choose the optimal broadband access technologies to residential and small business customers.

• Science of Emotion and Sensibility
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• v.15 no.3
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• pp.345-354
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• 2012

The purpose of this study is finding alternative parameters of the HRV so as to minimize the subjective errors by STAI and BDI, could be have two types of significant correlation levels depending on normalized method. Particularly, the LF/HF presented as the quantitative physiological parameter that can reflect both state-anxiety and trait-anxiety.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.3
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• pp.20-28
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• 2002

This paper describes the time sharing type high frequency resonant inviter can be used as power of induction heating. This closed inverter can be obtained output frequency three times than switching frequency by composing three unit inviter of conventional Half-Bridge serial resonant inverter in parallel with input power source also, this reduce switching loss because it has ZVS function. The analysis of the proposed circuit is generally described by using the normailized proposed parameters. The principle of basic operating and the its charasteristics are extimated by the parameters such as switching frequency($\mu$), the variation of Phase angle($\phi$) of Phase-shift. Experimental results are presented to verify theoretical discussion. This preposed inverter will be able to be prastically used as a power supply in various fields as induction, heating application, DC-DC converter etc.

• International Journal of Highway Engineering
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• v.9 no.4
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• pp.55-63
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• 2007

Deformational characteristics of subgrade soils are important properties in the mechanistic analysis and design of pavement system. In this study, to evaluate the effect of specimen construction methods on deformational characteristics of subgrade soils in Korea, resonant column tests were performed for specimens constructed by various methods. Specimen construction method affected to the modulus value but the variation in the normalized modulus reduction curve was almost identical. The effects of specimen construction method on modulus are decreased with increasing confining pressure. The average maximum variation in the modulus value with different specimen construction methods was estimated as 16.8%. The differences in the modulus value of the specimens with same water content and dry density conditions that made by gyratory compaction and impact compaction were very small within 5.2%. The impact compaction method was proposed as a specimen construction method for determining the design input parameter testing considering that impact compaction method is much simpler and require less expensive specimen construction equipment and setup than gyratory compaction method.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.6
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• pp.681-686
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• 2012

This paper studied the speech parameters less affected by the human emotion for the development of the robust emotional speech recognition system. For this purpose, the effect of emotion on the speech recognition system and robust speech parameters of speech recognition system were studied using speech database containing various emotions. In this study, mel-cepstral coefficient, delta-cepstral coefficient, RASTA mel-cepstral coefficient, root-cepstral coefficient, PLP coefficient and frequency warped mel-cepstral coefficient in the vocal tract length normalization method were used as feature parameters. And CMS (Cepstral Mean Subtraction) and SBR(Signal Bias Removal) method were used as a signal bias removal technique. Experimental results showed that the HMM based speaker independent word recognizer using frequency warped RASTA mel-cepstral coefficient in the vocal tract length normalized method, its derivatives and CMS as a signal bias removal showed the best performance.

• Korean Journal of Remote Sensing
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• v.25 no.2
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• pp.95-105
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• 2009

Irregular temporal sampling is a common feature of geophysical and biological time series in remote sensing. This study proposes an on-line system for reconstructing observation image series including bad or missing observation that result from mechanical problems or sensing environmental condition. The surface parameters associated with the land are usually dependent on the climate, and many physical processes that are displayed in the image sensed from the land then exhibit temporal variation with seasonal periodicity. An adaptive feedback system proposed in this study reconstructs a sequence of images remotely sensed from the land surface having the physical processes with seasonal periodicity. The harmonic model is used to track seasonal variation through time, and a Gibbs random field (GRF) is used to represent the spatial dependency of digital image processes. In this study, the Normalized Difference Vegetation Index (NDVI) image was computed for one week composites of the Advanced Very High Resolution Radiometer (AVHRR) imagery over the Korean peninsula, and the adaptive reconstruction of harmonic model was then applied to the NDVI time series from 1996 to 2000 for tracking changes on the ground vegetation. The results show that the adaptive approach is potentially very effective for continuously monitoring changes on near-real time.