• 한국지하수토양환경학회지:지하수토양환경
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• 제19권6호
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• pp.1-5
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• 2014

The following research was initiated in order to compare the relationship between the amount of gunfire shot and its resulting heavy metal pollution rate. The research was conducted at two firing ranges located inside a military unit stationed in the rear strategical area, where one full distance firing range is used by soldiers in active service, and the other is used by recruits and reserves. The heavy metal pollution rate was measured also on water sample collected from the target zone while raining. Based on values such as the real amount of gunshot fired, amount of heavy metal in the soil of the target zone, and the degree of heavy metal pollution for each firing range, the research showed that although pollution rate was higher when more gunshots were fired, there was no close correlation between the two. The water samples showed that this might result from the soils containing heavy metals eroded and transported by rain due to the target zone having no vegetation.

• 한국컴퓨터정보학회논문지
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• 제26권12호
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• pp.11-18
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• 2021

본 논문에서는 함포 사격 정확도를 향상시키기 위해 표적 위치 예측과 사격 오차 도출에서의 딥러닝 알고리즘 적용 가능성을 연구하였다. 표적 위치 예측 시 딥러닝 알고리즘의 하나인 LSTM 모델과 RN 구조를 적용했을 때 좀 더 정밀한 표적 위치를 예측할 수 있다는 가능성을 확인하고 모델을 설계하였다. 사격 오차 도출 시 사격제원 계산에 영향을 끼치는 요소들을 데이터 셋으로 관리하며, GAN을 사용하여 데이터 셋을 생성 후 강화 학습을 진행하여 사격 오차를 줄일 수 있는 모델을 설계하였다. 2가지 모델을 결합하여 사격 정확도를 향상시키기 위한 딥러닝 기반의 사격제원 계산 모델을 설계하였다.

• Advances in aircraft and spacecraft science
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• 제1권3호
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• pp.273-289
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• 2014

Accuracy of a reconstruction technique assuming a constant characteristic exhaust velocity ($c^*$) efficiency for reducing hybrid rocket firing test data was examined experimentally. To avoid the difficulty arising from a number of complex chemical equilibrium calculations, a simple approximate expression of theoretical $c^*$ as a function of the oxidizer to fuel ratio (${\xi}$) and the chamber pressure was developed. A series of static firing tests with the same test conditions except burning duration revealed that the error in the calculated fuel consumption decreases with increasing firing duration, showing that the error mainly comes from the ignition and shutdown transients. The present reconstruction technique obtains ${\xi}$ by solving an equation between theoretical and experimental $c^*$ values. A difficulty arises when multiple solutions of ${\xi}$ exists. In the PMMA-LOX combination, a ${\xi}$ range of 0.6 to 1.0 corresponds to this case. The definition of $c^*$ efficiency necessary to be used in this reconstruction technique is different from a $c^*$ efficiency obtained by a general method. Because the $c^*$ efficiency obtained by average chamber pressure and ${\xi}$ includes the $c^*$ loss due to the ${\xi}$ shift, it can be below unity even when the combustion gas keeps complete mixing and chemical equilibrium during the entire period of a firing. Therefore, the $c^*$ efficiency obtained in the present reconstruction technique is superior to the $c^*$ efficiency obtained by the general method to evaluate the degree of completion of the mixing and chemical reaction in the combustion chamber.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권6호
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• pp.133-139
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• 2015

Attention to munitions constituents such as 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in the firing ranges is increasing due to their toxicity and high mobility to the environment. It is helpful to use a systemic model to predict the amount of contaminants for the establishment of environmental management of firing ranges. This study employed Training Range Environmental Evaluation and Characterization System (TREECS) program to estimate the mobility characteristics of TNT and RDX via groundwater leaching, soil erosion and surface water runoff. The prediction results of the TNT and RDX migration with TREECS showed that 68% of initial TNT and 21% of initial RDX were discharged through the soil erosion and the 20% of initial TNT and 54% of initial RDX ran out the firing range via the groundwater leaching. The rest of the initial TNT and RDX moved to adjacent surface water via surface runoff. The data suggest that soil erosion and surface runoff occupying 80% of TNT to the total amount are important migration pathways. On the other hand, groundwater leachning occupying 54% to the total amount was also important pathway for RDX.

• Journal of Korean Neurosurgical Society
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• 제42권6호
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• pp.455-461
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• 2007

Objective : It was hypothesized that dopamine agonist administration and subthalamic nucleus (STN) lesion in the rat might have a synergistic effect on the neuronal activities of substantia nigra pars reticulata (SNpr) as observed in patients with Parkinson's disease. The effects of SKF38393 (a $D_1$ receptor agonist) and Quinpirole (a $D_2$ receptor agonist) were compared in parkinsonian rat models with 6- hydroxydopamine (6-OHDA) after STN lesion. Methods : SKF38393 and Quinpirole were consecutively injected intrastriatally. SNpr was microrecorded to ascertain the activity of the basal ganglia output structure. The effect of SKF38393 or Quinpirole injection on the firing rate and firing patterns of SNpr was investigated in medial forebrain bundle (MFB) lesioned rats and in MFB+STN lesioned rats. Results : The administration of SKF38393 decreased SNpr neuronal firing rates and the percentage of burst neurons in the MFB lesioned rats, but did not alter them in MFB+STN lesioned rats. The administration of Quinpirole significantly decreased the spontaneous firing rate in the MFB lesioned rats. However, after an additional STN lesion, it increased the percentage of burst neurons. Conclusion : This study demonstrated that dopamine agonists and STN lesion decreased the hyperactive firing rate and the percentage of burst neurons of SNpr neurons in 6-OHDA lesioned rats, respectively. Quinpirole with STN lesion increased a percentage of burst neurons. To clear the exact interactive mechanism of $D_1$ and $D_2$ agonist and the corresponding location, it should be followed a study using a nonselective dopamine agonist and $D_1$, $D_2$ selective antagonist.

• The Korean Journal of Physiology and Pharmacology
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• 제15권6호
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• pp.371-382
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• 2011

We performed experiments using Aplysia neurons to identify the mechanism underlying the changes in the firing patterns in response to temperature changes. When the temperature was gradually increased from $11^{\circ}C$ to $31^{\circ}C$ the firing patterns changed sequentially from the silent state to beating, doublets, beating-chaos, bursting-chaos, square-wave bursting, and bursting-oscillation patterns. When the temperature was decreased over the same temperature range, these sequential changes in the firing patterns reappeared in reverse order. To simulate this entire range of spiking patterns we modified nonlinear differential equations that Chay and Lee made using temperature-dependent scaling factors. To refine the equations, we also analyzed the spike pattern changes in the presence of potassium channel blockers. Based on the solutions of these equations and potassium channel blocker experiments, we found that, as temperature increases, the maximum value of the potassium channel relaxation time constant, ${\tau}_n(t)$ increases, but the maximum value of the probabilities of openings for activation of the potassium channels, n(t) decreases. Accordingly, the voltage-dependent potassium current is likely to play a leading role in the temperature-dependent changes in the firing patterns in Aplysia neurons.

• 한국자동차공학회논문집
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• 제15권3호
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• pp.133-140
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• 2007

The purpose of this study was to evaluate the effects of gasoline fuel to the LPI engine. Firing test bench was used in order to assess the effect on gasoline-injected LPI engine. Gasoline fuel was supplied into the reverse direction(3-4-2-1 cylinder) at 3.0 bar with commercial gasoline fuel pump. Engine test was performed using the firing test mode at end of line. The deviations of excess air ratio of each cylinder and maximum combustion pressure using gasoline fuel were within 0.1 and $1{\sim}2\;bar$. Engine start time was measured with changing coolant temperature at $20^{\circ}C,\;40^{\circ}C,\;80^{\circ}C$, respectively. Residual gasoline volume in the fuel line was measured about 32 cc after firing test and it was less than 2 cc within 10 seconds purging. To simulate the end of line, the residual gasoline in the fuel line was purged during 5 and 10 seconds. Start time of LPI engine with LPG fuel were 0.61 and 0.58 seconds. This work showed that severe problems such as misfiring and liner scuffing were not occurred applying gasoline fuel to LPI engine.

• 한국항공우주학회지
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• 제32권9호
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• pp.122-129
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• 2004

소형 액체 엔진의 개발을 위한 과정에는 정확한 추력 측정이 성공적인 시험 및 평가를 위해 필수적이다. 본 논문에서는 추력 측정 장치의 개발을 위해 고려해야 할 설계 요소 및 제작 과정 동을 살펴본다. 측정 장치의 특정들이 기술되고 진공 환경을 모사한 연소 시험을 통해서 그 성능을 평가하였다. 측정 장치의 성능 시험을 위해 추진제 주입 압력의 변화에 따라 정상모드와 펄스모드에서 연소 시험을 수행하였으며 고유 진동수 및 구조물 의 선형성 시험과 같은 특성 시험을 통해 소형 액체 엔진의 정확한 추력 측정을 위한 적합성을 확인하였다.

• 생물환경조절학회지
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• 제15권1호
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• pp.107-113
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• 2006

These studies were carried out to investigate the quality of green tea processed by different pan-firing hand rolling and to select the best conditions during the procedure of green tea processing the results were as follows. At harvestion tea plant leaf, tea plants had 4 leaves. each leaf size was 7.5 cm'$\square$2.6 cm, and weight of 100 buds 46.6 g. The increase of pan-fired time decreased in the moisture content and yield of green tea. After processing green tea, 5 times pan-fired one had much more contents of total nitrogen (T-N:5.31%), caffeine (2.00%) and total amino acid (T.A.A. : 3,046 mg%) and less content of tannin (13.41%) than the other treatments. but 3 times pan-fired one had the highest contents of vitamin C (204.3 mg%) and chlorophyll (365.0 mg%) among three kinds pan-firing method. Sixteen kinds of free amino acid including theanine as a good taste component of pan-fired green tea were isolated and measured by HPLC. Free amino acid (FAA) contents were in the range of $2,683{\sim}2,925$ mg% and among various pan-firing methods, 5 tims pan-fired one had the highest content of F.A.A. Among these free amino acids, theanine occupied as much as $56.4{\sim}61.3%$ of F.A.A. Lightness, yellowness and redness of 5 times pan-fired green tea were middle value among three different treatments. Besides, it gained the highest score of sensory evaluation among them. These above results suggested that 5 times pan-fired green tea was considered to be the best level as pan-firing times of green tea processing.

• Korean Journal of Acupuncture
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• 제25권3호
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• pp.117-135
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• 2008

Objectives: It is known that the vestibular imbalance leads to vestibular symptoms such as nausea, vomiting, vertigo and postural disturbance. Since the non-labyrinthine inputs from the limbs and viscera converge on the vestibular nucleus neurons receiving signal from peripheral vestibular endorgan, acupuncture to the periphery may influence the activities of vestibular nuclear neurons and produce a therapeutic effect on the vestibulacr symptoms. The present study was to examine a modification and characteristics of the static and dynamic activities of medial vestibular nucleus (MVN) neurons following electroacupuncture (EA) of GB43' acupoint. Methods: In 54 Sprague-Dawley adult male rats weighing 250${\sim}$300g, spontaneous firing discharges and dynamic responses induced by sinusoidal whole body rotation about vertical axis at 0.2 Hz were observed in MVN of rats during EA of GB43' acupoint, located between the left 4th and 5th toe, which is the territory of sural and peroneal nerves, with 0.2 ms, 40 Hz and 600${\pm}$200 ${\mu}A$. Results: EA of the left GB43' acupoint induced modifications of spontaneous firing rates in 45% of MVN neurons recorded, and the percentage of modified neurons was 44% in type I, 52% in type II and 46% in non-type neurons. The excitatory or inhibitory responses of spontaneous firing discharges were predominant in the ipsilateral MVN neurons during EA. The excitatory response was abolished after EA but the inhibitory response was prolonged after EA in the ipsilateral MVN. The neurons of MVN showing modified spontaneous firing discharges by EA showed lower frequency (${\geq}$10 spikes/sec) of mean spontaneous firing rates than non affected ones. Conclusion: These results suggest that the neuronal activities of MVN neurons were influenced by EA of GB43' acupoint and the effects of EA may be related to the convergence of the peripheral vestibular inputs and ascending somatosensory inputs on MVN.