• Current Research on Agriculture and Life Sciences
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• v.4
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• pp.141-153
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• 1986

This study intends to document the existing cyclical fluctuations of garic and onion price at farm gate level during the period of 1966-1986 in Korea. The existing patterns of such cyclical fluctuations were estimated systematically by removing the seasonal fluctuation and irregular movement as well as secular trend from the original price through the moving average method. It was found that the cyclical fluctuations of garic and onion prices repeated six and seven times respectively during the same period, also the amplitude coefficient of cyclical fluctuations showed speed up in recent years. It was noticed that the cyclical fluctuations of price in onion was higher than that of in garic.

• Clinical and Experimental Pediatrics
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• v.52 no.5
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• pp.538-543
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• 2009

Purpose : To report the clinical experience with amitriptyline for managing children with cyclic vomiting syndrome (CVS). Methods : Totally, eleven children (eight males) were diagnosed with CVS. Of these, medical records were reviewed for eight children treated with amitriptyline; three children were not treated because one was not followed up and two were kept under observation to study the natural course without medication, because the frequency of vomiting had recently decreased to less than one episode per year. The eight amitriptyline-treated children were divided into three groups by the therapeutic response: (1) complete remission (CR), with no recurrence of symptoms after treatment; 2) partial remission (PR), in which the frequency of symptoms decreased by almost 50% after treatment; and (3) no response. Results : For the eight amitriptyline-treated children, the mean age of symptom onset was 4.7 (0.3-7) yr and mean age at diagnosis was 8.9 (6.0-11.3) yr. The mean number of vomiting episodes was 8.8 (2-25) per year, and the duration of vomiting in each episode ranged from 3 hours to 5 days. CR was achieved in five (62.5%) of the eight amitriptyline-treated children (0.2-0.8 mg/kg/day orally, at night) and PR was achieved in three children (37.5%). Two children relapsed on discontinuation of amitriptyline by their parents decision but showed improvement on remedication. No adverse effects were noted throughout the study period. Conclusion : Amitriptyline can be used in long-term prophylaxis for the management of children with CVS aged over 6 yr. However, a large-scale study is needed to ascertain its effects.

• Journal of Biomedical Engineering Research
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• v.20 no.5
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• pp.573-579
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• 1999

본 논문은 2채널 센서를 이용한 펄스 옥시메터의 산소포화도 계산 모델의 설계 및 분석에 관한 것이었다. 또한 Beer Lambert 법칙에 의거하여 기존 알고리즘 및 새로운 알고리즘들을 이론적으로 분석하였다. 제안된 알고리즘은 손가락을 투과한 2개의 채널에서 나온 광신호를 각각 직류성분 Adc 와 맥동성문 Aasin wt. 잡음성분 Ahnoise , ALnoise 등으로 모델링한다. 모델링 되어진 광신호를 맥동성분이 적분비를 사용하여 고주파 동잡음인 AHnoise 를 제거한 후 각각 산소포화도 계산을 위한 상관계수 그래프를 구한다. 또한 2개의 채널에서 적분비를 사용하여 구해진 상관계수 그래프를 사용하여 산소농도를 추출하는 방법에 관하여 기술하였다. 맥동성분비와 관혈적인 측정에 의한 혈중 산소포화도와의 상관관계 그래프의 선형성을 확보하기 위하여 펄스 옥시메터 시뮬레이터 오차범위를 고려해 75~100%상이의 산소포화도를 중점적으로 관측하였고, 4주기로 면적계산주기를 결정하여 실험하였다. 본 연구에서 제안된 알고리즘의 성능평가는 맥동성분의 적분비를 이용한 방법과 비교하였다. 비교결과는 4주기의 면적계산 주기를 가졌을 때 기존의 방식보다 평균오차가 0.7%정도 향상되었으며, 회귀적선의 신뢰도를 보여주는 결정계수 ${\gamma}$$^2$도 0.995로 기존의 방식에서 나온 0.979보다 더 좋은 결과를 얻을 수 있었다. 따라서 2채널을 이용한 방법이 A Lnoise 제거와 성능면에서 우수하다는 결론을 얻을 수 있었다.

• Journal of Aerospace System Engineering
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• v.15 no.1
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• pp.63-71
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• 2021

The South Korean Navy has operated Harpoon guided missiles through step-by-step acquisition after adopting them for the first time in 1978. As Harpoon guided missiles have been operated for a long time, it is necessary to make an active follow-up logistics support to guarantee their performance. Inspection of guided missiles is a basic activity to check the status of missiles. This study was conducted to check if the existing inspection interval of Harpoon guided missiles that have been operated for a long time was appropriate. Regarding research methods, based on the Navy's field operation materials, this study analyzed and presented inspection interval by section according to the period of operation, utilizing the Martinez's theory and a non-parametric MCF technique.

• Korean Journal of Clinical Laboratory Science
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• v.49 no.3
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• pp.294-299
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• 2017

The aim of this study was to detect the status of epilepticus and seizure based on the initial patterns observed in the first 30 minutes of continuous electroencephalogram (cEEG) monitoring. An cEEG was recorded digitally using electrodes applied according to the International 10~20 System. The EEG data were reviewed from January 2014 to December 2015. The baselines of the EEG patterns were characterized by lateralized periodic discharges, generalized periodic discharges, burst suppression, focal epileptiform, asymmetric background, generalized slowing, and generalized periodic discharges with a triphagic wave. The etiology was classified into five categories. The subjects of this study were 128 patients (age: $56.9{\pm}17.5years$, male:female, 74:54). The mean cEEG monitoring duration was $5.5{\pm}5.1$ (min:max, 1:33) days. The EEG pattern categories included lateralized periodic discharges (N=7), generalized periodic discharges (N=10), burst suppression (N=6), focal epileptiform (N=19), asymmetric background (N=24), generalized slowing (N=51), and generalized periodic discharges with a triphagic wave (N=11). The etiological classifications of the patients with status epilepticus were remote symptomatic (N=4), remote symptomatic with acute precipitant (N=9), acute symptomatic (N=6), progressive encephalopathy (N=2), and febrile seizure (N=1). cEEG monitoring was found to be useful for the diagnosis of non-convulsive epileptic seizures or status epilepticus. The seizure was confirmed by the EEG pattern.

• Journal of Navigation and Port Research
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• v.27 no.4
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• pp.455-463
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• 2003

Time series of suspended sediment concentration, surface elevation and velocity were measured and analysed to investigate the role of waves and the predominance of infra-gravity wave component for sediment suspension phenomena in the surf zone. For the investigation in detail, we adopted the cross spectral analysis method between suspended sediment concentration and the characteristic values of wave, and ensemble average analysis method about long-period wave component, which is dominant to sediment suspension in the measurement point. The obtained results are summarized as follows: 1)The relationship between suspended sediment concentration and the characteristic values of wave is stronger for the long-period standing wave components(about 60s and 30s where the nodal point of the first mode and the anti-nodal point of the second mode are located at the measurement point, respectively) than the long wave components(about 100s), which have the most energetic power, 2) and also, it is cleared that suspended sediment concentration is increased in the case of the phase, the velocity components of the first mode long-period standing wave(60sec) were accelerated toward on-shore direction, that is, the water surface in offshore side is higher than on-shore side.

• Korean Journal of Optics and Photonics
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• v.33 no.1
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• pp.11-21
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• 2022

We have investigated the optimal design of an aperiodic optical phased array (OPA) for use in light detection and ranging applications. Three optimization algorithms - particle-swarm optimization (PSO), a genetic algorithm (GA), and a pattern-search algorithm (PSA) - were employed to obtain the optimal arrangement of optical antennas comprising an OPA. The optimization was performed to obtain the minimal side-lobe level (SLL) of an aperiodic OPA at each steering angle, using the three optimization algorithms. It was found that PSO and GA exhibited similar results for the SLL of the optimized OPA, while the SLL obtained by PSA showed somewhat different features from those obtained by PSO and GA. For an OPA optimized at a steering angle <45°, the SLL value averaged over all steering angles increased as the angle of optimization decreased. However, when the angle of optimization was larger than 45°, low average SLL values of <13 dB were obtained for all three optimization algorithms. This implies that an OPA with high signal quality can be obtained when the arrangement of the optical antennas is optimized at a large steering angle.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1A
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• pp.75-89
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• 2006

This paper presents a practical and realistic Life-Cycle Cost (LCC) optimum design methodology of steel bridges considering time effect of bridge reliability under environmental stressors such as corrosion and heavy truck traffics. The LCC functions considered in the LCC optimization consist of initial cost, expected life-cycle maintenance cost and expected life-cycle rehabilitation costs including repair/replacement costs, loss of contents or fatality and injury losses, road user costs, and indirect socio-economic losses. For the assessment of the life-cycle rehabilitation costs, the annual probability of failure which depends upon the prior and updated load and resistance histories should be accounted for. For the purpose, Nowak live load model and a modified corrosion propagation model considering corrosion initiation, corrosion rate, and repainting effect are adopted in this study. The proposed methodology is applied to the LCC optimum design problem of an actual steel box girder bridge with 3 continuous spans (40 m+50 m+40 m=130 m), and various sensitivity analyses of types of steel, local corrosion environments, average daily traffic volume, and discount rates are performed to investigate the effects of various design parameters and conditions on the LCC-effectiveness. From the numerical investigation, it has been observed that local corrosion environments and the number of truck traffics significantly influence the LCC-effective optimum design of steel bridges, and thus realized that these conditions should be considered as crucial parameters for the optimum LCC-effective design.

• Proceedings of the Korean Society of Crop Science Conference
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• 2007.11a
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• pp.242.2-242.2
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• 2007

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.5 no.4
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• pp.357-368
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• 1993

With the assumption of the diffusion dominated flow, a numerical model has been developed for undertow and turbulence structure under the breaking wave by using the $textsc{k}$-$\varepsilon$ turbulence model. Undertow is a strong mean current which moves seqwards below the level of wave trough in the surf zone. The turbulence, generated by wave breaking in the roller, spreads and dissipates downwards. The governing equations are composed of the equation of motion with the period-averaged shear stress due to waves; $textsc{k}$- and $\varepsilon$-equations with the turbulence energy Production due to wave breaking. They are discretised by the three-level fully implicit scheme, which can be solved by using Thomas algorithm. The model gives good agreements with measurements except for the station that is closest to the breaking point.