• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.1135-1139
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• 2017

Spatial distribution of chemical species in flame is a important indicator understanding the flame structure and combustion characteristics, and optical emission spectroscopy has been widely used for the measurement because of its simple and non-intrusive methodology. In this study, we suggest the feasibility of the measurement of chemical species (OH radical) distribution in rocket plume using optical emission spectrometer which was developed for the spatially resolved measurement along the line-of-sight. In order to predict the ground state concentration of species from the measured emission intensity by optical emission spectrometer, we consider thermal and chemical excitation mechanisms in flame, and assume thermodynamic equilibrium for the thermally excited species. We also present the spatial resolution and the correction of collection characteristics of the optical emission spectrometer depending on object distance.

• Advances in Computational Design
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• v.4 no.2
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• pp.73-90
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• 2019

The growth in the number of single-member households is a critical issue worldwide, especially among the elderly. For those living alone, who may be unaware of their health status or routines that could improve their health, a continuous healthcare monitoring system could provide valuable feedback. Assessing the performance adequacy of activities of daily living (ADL) can serve as a measure of an individual's health status; previous research has focused on determining a person's daily activities and extracting the most frequently performed behavioral patterns using camera recordings or wearable sensing techniques. However, existing methods used to extract common patterns of an occupant's activities in the home fail to address the spatio-temporal dimensions of human activities simultaneously. Though multiple sequence alignment (MSA) offers some advantages - such as inherent containment of the spatio-temporal data in sequence format, and rapid identification of hidden patterns - MSA has rarely been used to extract in-home ADL routines. This research proposes a method to extract a household occupant's ADL routines from a cumulative spatio-temporal data log of occupancy collected using a non-intrusive method (i.e., a tomographic motion detection system). The findings from an occupant's 28-day spatio-temporal activity log demonstrate the capacity of the proposed approach to identify routine patterns of an occupant's daily activities and to reveal the order, duration, and frequency of routine activities. Routine ADL patterns identified from the proposed approach are expected to provide a basis for detecting/evaluating abrupt or gradual changes of an occupant's ADL patterns that result from a physical or mental disorder, and can offer valuable information for home automation applications by enabling the prediction of ADL patterns.

• Journal of the Korea Convergence Society
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• v.12 no.2
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• pp.21-28
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• 2021

In this study, we propose a deep learning-based NILM technique using actual measured power data for 5 kinds of home appliances and verify its effectiveness. For about 3 weeks, the active power of the central power measuring device and five kinds of home appliances (refrigerator, induction, TV, washing machine, air cleaner) was individually measured. The preprocessing method of the measured data was introduced, and characteristics of each household appliance were analyzed through spectogram analysis. The characteristics of each household appliance are organized into a learning data set. All the power data measured by the central power measuring device and 5 kinds of home appliances were time-series mapping, and training was performed using a LSTM neural network, which is excellent for time series data prediction. An algorithm that can disaggregate five types of energies using only the power data of the main central power measuring device is proposed.

• Earthquakes and Structures
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• v.22 no.3
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• pp.245-261
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• 2022

Key questions to researchers interested in nonlinear analysis of skeletal structures are whether the distributed plasticity approach - albeit computationally demanding - is more reliable than the concentrated plasticity to adequately capture the extent and severity of the inelastic response, and whether force-based formulation is more efficient than displacement-based formulation without compromising accuracy. The present research focusing on performance-based seismic response of mid-span concrete bridges provides a pilot holistic investigation opting for some hands-on answers. OpenSees software is considered adopting different modeling techniques, viz. distributed plasticity (through either displacement-based or force-based elements) and concentrated plasticity via beam-with-hinges elements. The pros and cons of each are discussed based on nonlinear pushover analysis results, and fragility curves generated for various performance levels relying on incremental dynamic analyses under real earthquake records. Among prime conclusions, distributed plasticity modeling albeit inherently not relying on prior knowledge of plastic hinge length still somewhat depends on such information to ensure accurate results. For instance, displacement-based and force-based approaches secure optimal accuracy when dividing, for the former, the member into sub-elements, and satisfying, for the latter, a distance between any two consecutive integration points, close to the expected plastic hinge length. On the other hand, using beam-with-hinges elements is computationally more efficient relative to the distributed plasticity, yet with acceptable accuracy provided the user has prior reasonable estimate of the anticipated plastic hinge length. Furthermore, when intrusive performance levels (viz. life safety or collapse) are of concern, concentrated plasticity via beam-with-hinges ensures conservative predicted capacity of investigated bridge systems.

• Korea Science and Art Forum
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• v.16
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• pp.299-310
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• 2014

The purpose of this research propose the improvement of the visual arts educational environment according to the previous studies that is visual arts education have effect on the students' creativity and their Psychological Aspects. In addition, This study provide the preceding material in terms of the future quality of the environment and curriculum for public schools and indicate the advantages and disadvantages of each design space as examining what is needed aspect of the art connectivity. Research method is to investigate the domestic and International public school's visual arts education environment aspects of the facility and space status for safety and activity. As well, method is that it will find out how the program is being conducted in any part of the local culture. Art Education is not the non-intrusive training, but the series of processes going to work together and solve problems through participation of the creative experience based on the art motif. Therefore, it will be a well-supported guideline to establish the art educational environment.

• Economic and Environmental Geology
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• v.25 no.3
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• pp.337-349
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• 1992

The Tertiary basins in Korea have widely been studied by numerous researchers producing individual results in sedimentology, paleontology, stratigraphy, volcanic petrology and structural geology, but interdisciplinary studies, inter-basin analysis and basin-forming process have not been carried out yet. Major work of this study is to elucidate evidences obtained from different parts of a basin as well as different Tertiary basins (Pohang, Changgi, Eoil, Haseo and Ulsan basins) in order to build up the correlation between the basins, and an overall picture of the basin architecture and evolution in Korea. According to the paleontologic evidences the geologic age of the Pohang marine basin is dated to be late Lower Miocence to Middle Miocene, whereas other non-marine basins are older as being either Early Miocene or Oligocene(Lee, 1975, 1978: Bong, 1984: Chun, 1982: Choi et al., 1984: Yun et al., 1990: Yoon, 1982). However, detailed ages of the Tertiary sediments, and their correlations in a basin and between basins are still controversial, since the basins are separated from each other, sedimentary sequence is disturbed and intruded by voncanic rocks, and non-marine sediments are not fossiliferous to be correlated. Therefore, in this work radiometric, magnetostratigraphic, and biostratigraphic data was integrated for the refinement of chronostratigraphy and synopsis of stratigraphy of Tertiary basins of Korea. A total of 21 samples including 10 basaltic, 2 porphyritic, and 9 andesitic rocks from 4 basins were collected for the K-Ar dating of whole rock method. The obtained age can be grouped as follows: $14.8{\pm}0.4{\sim}15.2{\pm}0.4Ma$, $19.9{\pm}0.5{\sim}22.1{\pm}0.7Ma$, $18.0{\pm}1.1{\sim}20.4+0.5Ma$, and $14.6{\pm}0.7{\sim}21.1{\pm}0.5Ma$. Stratigraphically they mostly fall into the range of Lower Miocene to Mid Miocene. The oldest volcanic rock recorded is a basalt (911213-6) with the age of $22.05{\pm}0.67Ma$ near Sangjeong-ri in the Changgi (or Janggi) basin and presumed to be formed in the Early Miocene, when Changgi Conglomerate began to deposit. The youngest one (911214-9) is a basalt of $14.64{\pm}0.66Ma$ in the Haseo basin. This means the intrusive and extrusive rocks are not a product of sudden voncanic activity of short duration as previously accepted but of successive processes lasting relatively long period of 8 or 9 Ma. The radiometric age of the volcanic rocks is not randomly distributed but varies systematically with basins and localities. It becomes generlly younger to the south, namely from the Changgi basin to the Haseo basin. The rocks in the Changgi basin are dated to be from $19.92{\pm}0.47$ to $22.05{\pm}0.67Ma$. With exception of only one locality in the Geumgwangdong they all formed before 20 Ma B.P. The Eoil basalt by Tateiwa in the Eoil basin are dated to be from $20.44{\pm}0.47$ to $18.35{\pm}0.62Ma$ and they are younger than those in the Changgi basin by 2~4 Ma. Specifically, basaltic rocks in the sedimentary and voncanic sequences of the Eoil basin can be well compared to the sequence of associated sedimentary rocks. Generally they become younger to the stratigraphically upper part. Among the basin, the Haseo basin is characterized by the youngest volcanic rocks. The basalt (911214-7) which crops out in Jeongja-ri, Gangdong-myon, Ulsan-gun is $16.22{\pm}0.75Ma$ and the other one (911214-9) in coastal area, Jujon-dong, Ulsan is $14.64{\pm}0.66Ma$ old. The radiometric data are positively collaborated with the results of paleomagnetic study, pull-apart basin model and East Sea spreading theory. Especially, the successively changing age of Eoil basalts are in accordance with successively changing degree of rotation. In detail, following results are discussed. Firstly, the porphyritic rocks previously known as Cretaceous basement (911213-2, 911214-1) show the age of $43.73{\pm}1.05$ 및 $49.58{\pm}1.13Ma$(Eocene) confirms the results of Jin et al. (1988). This means sequential volcanic activity from Cretaceous up to Lower Tertiary. Secondly, intrusive andesitic rocks in the Pohang basin, which are dated to be $21.8{\pm}2.8Ma$ (Jin et al., 1988) are found out to be 15 Ma old in coincindence with the age of host strata of 16.5 Ma. Thirdly, The Quaternary basalt (911213-5 and 911213-6) of Tateiwa(1924) is not homogeneous regarding formation age and petrological characteristics. The basalt in the Changgi basin show the age of $19.92{\pm}0.47$ and $22.05{\pm}0.67$ (Miocene). The basalt (911213-8) in Sangjond-ri, which intruded Nultaeri Trachytic Tuff is dated to be $20.55{\pm}0.50Ma$, which means Changgi Group is older than this age. The Yeonil Basalt, which Tateiwa described as Quaternary one shows different age ranging from Lower Miocene to Upper Miocene(cf. Jin et al., 1988: sample no. 93-33: $10.20{\pm}0.30Ma$). Therefore, the Yeonil Quarterary basalt should be revised and divided into different geologic epochs. Fourthly, Yeonil basalt of Tateiwa (1926) in the Eoil basin is correlated to the Yeonil basalt in the Changgi basin. Yoon (1989) intergrated both basalts as Eoil basaltic andesitic volcanic rocks or Eoil basalt (Yoon et al., 1991), and placed uppermost unit of the Changgi Group. As mentioned above the so-called Quarternary basalt in the Eoil basin are not extruded or intruaed simultaneously, but differentiatedly (14 Ma~25 Ma) so that they can not be classified as one unit. Fifthly, the Yongdong-ri formation of the Pomgogri Group is intruded by the Eoil basalt (911214-3) of 18.35~0.62 Ma age. Therefore, the deposition of the Pomgogri Group is completed before this age. Referring petrological characteristics, occurences, paleomagnetic data, and relationship to other Eoil basalts, it is most provable that this basalt is younger than two others. That means the Pomgogri Group is underlain by the Changgi Group. Sixthly, mineral composition of the basalts and andesitic rocks from the 4 basins show different ground mass and phenocryst. In volcanic rocks in the Pohang basin, phenocrysts are pyroxene and a small amount of biotite. Those of the Changgi basin is predominant by Labradorite, in the Eoil by bytownite-anorthite and a small amount pyroxene.

• The korean journal of orthodontics
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• v.25 no.3 s.50
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• pp.299-310
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• 1995

The purpose of this study is to know about the positional change of second molar when orthodontic treatment is performed. To know about it, we andlysed cephalogram pre. and post treatment for 54 adult patients who werefinished orthodontic treatment by banding to the first molar and classify them into 4 groups Class I extraction group 15, Class I nonextraction group 12, Class II group 13, class Class III group 14. The following conclusions were obtained : 1. In the extraction group of Class I , mandibular second molar showed less extrusion and mon distal inclination than first moarl. But maxillary second molar showed more or less extrusive and mesial inclination to much the same degree of first molar. 2. Inthe non-extractio group of Class I, mandibular second molar in intrusive to first molar, it showed smilar distal inclination to first molar. But maxillary second molar is extrusive similarly to first molar. 3. In the group of Class II , mandibular second molar is less extrusive than first molar and maxillary second molar is more extrusive than first molar. 4. In the group of Class III, mandibular second molar showed similar extrusion to first molar and more distal inclination than first molar. But maxillary second molar showed less extrusion than first molar. 5. A comparision of the positional change of second molar among groups : The change of distance from FH plane to funcation point of maxillary second molar is the difference between Class I extraction group and Class II group, Class I extraction group and Class III group. The change of maxillary second molar to palatal plane and occlusal plane is the difference between Class I extraction group and Class III group. And the change of distance from mandibular plan to furcation point of mandibular second molar is difference between Class I extraction group and non-extraction group, Class I non-extraction group and Class II group, Class I non-extraction group and Class III group. But the change of angle of mandibular second molar to mandibular plane and occlusal plane is make no difference in among groups.

• Journal of Korea Water Resources Association
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• v.45 no.9
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• pp.853-860
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• 2012

It is well-known that loop effect of the stage-discharge relationship is formulated based on many field observations especially for the sand rivers. Theoretical understandings of the loop effect for the sand rivers have been widely provided, based on the facts that it is driven by the flood wave propagation and bed form changes over the given flood period. However, very few theoretical studies or field observations associated with loop-rating curves in the gravel or rock-bed mountain streams have been attempted so far, due particularly to the difficulties in the accurate discharge measurement during the flood in such field conditions. The present paper aims to report a unique loop-rating curve measured at a gravel and rock-bed mountain stream based on the flood discharge observation acquired during the typhoon, Muifa that passed nearby Jeju Island in summer of 2011. As velocity instrumentation, a non-intrusive Surface Velocity Doppler Radar to be suitable for the flood discharge measurement was utilized, and discharges were consecutively measured for every hour. Interestingly, the authors found that the hysteresis of the loop-rating curve was adverse compared to the typical trend of the sand bed streams, which means that the discharge of the rising limb is smaller than the falling limb at the same stage. We carefully speculate that the adverse trend of the loop-rating curve in the gravel bed was caused by the bed resistance change that works differently from the sand bed case.

• Journal of the Korean Society of Groundwater Environment
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• v.1 no.2
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• pp.100-104
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• 1994

The rock matrix diffusion provides a retarding mechanism for sorbing and especially non-sorbing radionuclides. It has to be verified not only theoretically and experimentally but also from natural phenomena, before the mechanism can be incorporated fully into transport codes. The natural analogue studies, such as the concentration variation of radionuclides in profiles perpendicular to fluid-conducting fractures and to intrusive contact zones, have been believed to provide a validation. In thermal alteration zones of Naeduckri granite intruded by a pegmatite, large alkali and alkaline earth elements such as K, Rb, Sr, and Ba were moderately migrated during thermal alteration. Li, V. and Nb were also migrated about 9cm in width from the contact between the granite and the pegmatite. The concentration variation of these elements in thermally altered zones seems to be resulted from the local migration due to the re-equilibration among the elements released from the breakdown of primary minerals in the granite. Most of these natural analogue studies simply show only the concentration variation of elements without detailed informations on the diffusion time and other important data fir interpreting the behaviour of radionuclides, because of the absence of appropriate minerals for age data. Despite this problem, natural analogue studies will be needed for transport models of radionuclides in safety assessment.

• Journal of KIISE:Software and Applications
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• v.31 no.9
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• pp.1233-1245
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• 2004

Though biometrics to authenticate a person is a good tool in terms of security and convenience, typical authentication algorithms using biometrics may not be executed on resource-constrained devices such as smart cards. Thus, to execute biometric processing on resource-constrained devices, it is desirable to develop lightweight authentication algorithm that requires only small amount of memory and computation. Also, among biological features, face is one of the most acceptable biometrics, because humans use it in their visual interactions and acquiring face images is non-intrusive. We present a new face authentication algorithm in this paper. Our achievement is two-fold. One is to present a face authentication algorithm with low memory requirement, which uses support vector machines (SVM) with the feature set extracted by genetic algorithms (GA). The other contribution is to suggest a method to reduce further, if needed, the amount of memory required in the authentication at the expense of verification rate by changing a controllable system parameter for a feature set size. Given a pre-defined amount of memory, this capability is quite effective to mount our algorithm on memory-constrained devices. The experimental results on various databases show that our face authentication algorithm with SVM whose input vectors consist of discriminating features extracted by GA has much better performance than the algorithm without feature selection process by GA has, in terms of accuracy and memory requirement. Experiment also shows that the number of the feature ttl be selected is controllable by a system parameter.