• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.638-642
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• 2005

For gas hydrate exploration, long offset multichannel seismic data acquired using by the 4km streamer length in Ulleung basin of the East Sea. The dataset was processed to define the BSRs (Bottom Simulating Reflectors) and to estimate the amount of gas hydrates. Confirmation of the presence of Bottom Simulating reflectors (BSR) and investigation of its physical properties from seismic section are important for gas hydrate detection. Specially, faster interval velocity overlying slower interval velocity indicates the likely presences of gas hydrate above BSR and free gas underneath BSR. In consequence, estimation of correct interval velocities and analysis of their spatial variations are critical processes for gas hydrate detection using seismic reflection data. Using Dix's equation, Root Mean Square (RMS) velocities can be converted into interval velocities. However, it is not a proper way to investigate interval velocities above and below BSR considering the fact that RMS velocities have poor resolution and correctness and the assumption that interval velocities increase along the depth. Therefore, we incorporated Migration Velocity Analysis (MVA) software produced by Landmark CO. to estimate correct interval velocities in detail. MVA is a process to yield velocities of sediments between layers using Common Mid Point (CMP) gathered seismic data. The CMP gathered data for MVA should be produced after basic processing steps to enhance the signal to noise ratio of the first reflections. Prestack depth migrated section is produced using interval velocities and interval velocities are key parameters governing qualities of prestack depth migration section. Correctness of interval velocities can be examined by the presence of Residual Move Out (RMO) on CMP gathered data. If there is no RMO, peaks of primary reflection events are flat in horizontal direction for all offsets of Common Reflection Point (CRP) gathers and it proves that prestack depth migration is done with correct velocity field. Used method in this study, Tomographic inversion needs two initial input data. One is the dataset obtained from the results of preprocessing by removing multiples and noise and stacked partially. The other is the depth domain velocity model build by smoothing and editing the interval velocity converted from RMS velocity. After the three times iteration of tomography inversion, Optimum interval velocity field can be fixed. The conclusion of this study as follow, the final Interval velocity around the BSR decreased to 1400 m/s from 2500 m/s abruptly. BSR is showed about 200m depth under the seabottom

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.4
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• pp.743-753
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• 2001

This paper proposed the sizing system for womens lower clothes. The sizing system was classified according to 4 body types and 5 age groups. The size intervals of waist girth, hip girth, stature, and slacks length were 3cm, 4cm, 8cm, and 5cm respectively. Frequency distribution analyzed with waist girth, hip girth, and stature showed that the most frequent sizes were 86-100-158 in the fattest-medium length H type, 77-92-158 in the fat-short M type, 68-92-158 in the balanced-long A type, and 65-88-158 in the balanced-medium length A type. The number of the sizes for lower clothes, which had frequencies more than 4∼5%, was 33 and each size was presented with slacks length, skirt length, thigh girth, and knee girth. Also frequency distribution analyzed with waist girth, hip girth, and slacks length showed that the most frequent sizes were 86-100-90 in the fattest-medium length H type, 74-96-90 in the fat-short M type, 68-92-90 in the balanced-long A type, and 65-88-90 in the balanced-medium length A type. The sizing system classified by age group had 21 cases in the early twenties, 21 cases in the late twenties, 18 cases in the early thirties, 16 cases in the late thirties, and 8 cases in the forties. This result will contribute to clothing fitness and efficient production.

• Steel and Composite Structures
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• v.36 no.2
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• pp.229-247
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• 2020

This study analyzed stresses in concrete and its reinforcement, computing the additional loading transferred by concrete creep. The loading varied from zero, structure exclusively under its self-weight, up to the critical buckling load. The studied structure was a real, tapered, reinforced concrete pole. As concrete is a composite material, homogenizing techniques were used in the calculations. Due to the static indetermination for determining the normal forces acting on concrete and reinforcement, equations that considered the balance of forces and compatibility of displacement on cross-sections were employed. In the mathematical solution used to define the critical buckling load, all the elements of the structural dynamics present in the system were considered, including the column self-weight. The structural imperfections were linearized using the geometric stiffness, the proprieties of the concrete were considered according to the guidelines of the American Concrete Institute (ACI 209R), and the ground was modeled as a set of distributed springs along the foundation length. Critical buckling loads were computed at different time intervals after the structure was loaded. Finite element method results were also obtained for comparison. For an interval of 5000 days, the modulus of elasticity and critical buckling load reduced by 36% and 27%, respectively, compared to an interval of zero days. During this time interval, stress on the reinforcement steel reached within 5% of the steel yield strength. The computed strains in that interval stayed below the normative limit.

• The Korean Journal of Applied Statistics
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• v.21 no.3
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• pp.509-521
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• 2008

Two control charts are usually required to monitor both the process mean and variance. In this paper, we introduce control procedures for jointly monitoring the process mean and variance with one control chart, and investigate efficiency of the introduced charts by comparing with the combined two EWMA charts. Our numerical results show that the GLR chart, the Omnibus EWMA chart, and the Interval chart have good ARL properties for simultaneous changes in the process mean and variance.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.311-312
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• 2002

In this paper a systematic design approach to determine the optimum size (height) of circulating fluidized bed heat exchanger for exhaust gas heat recovery is prososed. Unlike the convensional heat exchangers where the length of the heat exchanger section is not very much emphasized, the vertical length of heat exchanger tube in the case of fluidized bed heat exchangers is important because this length determines the time interval during which particles reside and transfer heat in the heat exchanger section. For particles initial conditions are nearly stationary, accelerating particles motion should be considered rather than simply assuming fully developed condition. A way to estimate optimum tube length at different fluid velocity and particle sizes is suggested based on the required conditioning time for heat transfer from the flue gas to solid particles.

• Journal of the Korean Home Economics Association
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• v.43 no.1 s.203
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• pp.105-113
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• 2005

The purpose of this study was to suggest a standard sizing system for college female students' head wears according to their head types. The subjects were 193 college women, of 20 to 25 years-old. The subjects were directly measured anthropometrically and indirectly analyzed photographically. In previous tudy (Lim, 2004), 3 clusters as their head types were categorized. the sizing system, which had frequencies more than $4\%$ was classified 6 cases, 7 cases and 9 cases, respectively, by head 3 types. 3 types of size system, which were 56-28-38, 56-30-38 and 57-28-38(Eds note: which of the measurements are head girth, surface length 1 and surface length 2), which were included in 3 clusters. Although head girths were as the same, head surface length was different in size. On the contrary, head surface length was same, head girth was different. The result will contribute to fitness of head wear fitness of consumer, and the amount of production.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.1
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• pp.70-75
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• 2013

The electrical separation joint as a filter circuit distributes the track circuit frequency. The electrical separation joint is classified into the interval where reinforcing bars are insulated and not insulated through the length of track circuit. In case of incorrectly setting up the length of electrical separation joint, the amplitude of current on the track circuit is not over standard current which is the standard of current on the track circuit and it effects on the close frequency on track circuit. Then, it makes an accident or makes a train not receive information for train control. In this paper, the electrical separation joint model is suggested and parameters are numerically calculated in the model. Moreover, the length of electrical separation joint is analyzed and is demonstrated by uisng Matlab and PSpice program.

• Journal of Trauma and Injury
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• v.29 no.4
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• pp.139-145
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• 2016

Purpose: The major pelvic trauma results in high mortality with associated fatal other injuries. During early stage of resuscitation, multidisciplinary approach is essential to improve the survival and outcomes. This study aims to report the effect and positive outcome of the trauma team approach on the management of hemodynamically unstable pelvic bone fracture. Methods: This retrospective review included all patients with hemodynamically unstable pelvic bone fracture admitted between March 2007 and December 2015. Patients were divided into group A, which comprised those admitted before the trauma team approach was started, and group B, which comprised those admitted after the approach was started. The advanced trauma life support protocol was followed for all patient. The comparisons between the two groups were based on medical records. Study variables included demographics, initial vital sign, injury severity score, fracture type, and injury mechanism. We analyzed the outcomes in each group with respect to the time interval for doctors' arrival, total length of stay in the emergency department (ED), time interval for computed tomography evaluation, 24-hour mortality, time interval for definitive fixation, and definitive fixation in the time-window of opportunity. Results: Fifty-three patients met the inclusion criteria. No statistically significant differences in demographic data existed between the two groups. The time interval for doctors' arrival (min, $63.09{\pm}50.48$ vs $21.48{\pm}17.75$; p=0.038) and total length of stay in the ED (min, $269.33{\pm}105.96$ vs $115.49{\pm}56.24$; p=0.023) were significantly improved. The 24-hour mortality was not significantly different between the two groups.(%, 14.3 vs 12.0; p=1.000) However, the time interval for definitive fixation and definitive fixation in the time-window of opportunity showed better results. Conclusion: The trauma team approach has positive effects, which include initial resuscitation through multidisciplinary approach and shortening the time interval to definitive fixation, on the management of hemodynamically unstable pelvic bone fracture.

• Development and Reproduction
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• v.16 no.3
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• pp.205-217
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• 2012

The ovarian cycle, the biological minimum size, and artificial spawning frequency by artificial spawning induction of the female hard clam, Meretrix petechialis, were investigated by histological observations and morphometric data. The ovarian cycle of this species can be classified into five successive stages: early active stage, late active stage, ripe stage, partially spawned stage, and spent/inactive stage. The spawning period was from June to September, and the main spawning occurred between July and August when the seawater temperature exceeds over $20^{\circ}C$. The biological minimum size (shell length at 50% of first sexual maturity) in females were 40.39 mm in shell length (considered to be two years of age), and all clams over 50.1 mm in shell length sexually matured. In this study, the mean number of the spawned eggs by spawning induction increased with the increase of size (shell length) classes. In case of artificial spawning induction for the clams > 40.39 mm, the number of spawned eggs from the clams of a sized class was gradually decreased with the increase of the number of the spawning frequencies (the first, second, and third spawning). In the experiments of artificial spawning induction during the spawning season, the interval of each spawning of this species was estimated to be 15-18 days (approximately 17 days).

• The Korean Journal of Malacology
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• v.21 no.2 s.34
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• pp.81-93
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• 2005

Reproductive cycle with the gonadal phases, first sexual maturity, artificial spawning amount by the size and spawning interval of the hard clam, Meretrix lusoria were investigated by histological observations and morphometric data by artificial spawning induction. Meretrix lusoria is dioecious and oviparous. The reproductive cycle of this species can be classified into five successive stages: early active stage (January to March), late active stage (February to May), ripe stage (April to August), partially spawned stage (June to September), and spent/inactive stage (September to February). The spawning period was from June to September, and the main spawning occurred between July and August when the seawater temperature exceeds over $20^{\circ}C$. Percentage of first sexual maturity of female and male clams ranging from 40.0 to 45.0 mm in shell length was over 50%, and all clams over 50.0 mm in shell length sexually matured. Female and male clams ranging from 40.0 to 45.0 mm in shell length are considered to be two years old. Therefore, we assume that the hard clams of both sexes begin reproduction from two years of age. The mean number of the spawned eggs increased with the increase of size (shell length) classes. In case of artificial spawning induction, the number of spawned eggs from the clams of a sized class was gradually decreased with the increase of the number of the spawning frequencies (the first, second, and third spawnings). In the experiments of artificial spawning induction during the spawning season, the interval of each spawning was estimated to be 15-18 days (average 17 days).