• 대기
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• 제26권2호
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• pp.227-241
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• 2016

This study investigated the cause of the heavy snowfall that occurred in the East Coast of Korea from 6 February to 14 February 2014. The synoptic conditions were analyzed using blocking index, equivalent potential temperature, potential vorticity, maritime temperature difference, temperature advection, and ground convergence. During the case period, a large blocking pattern developed over the Western Pacific causing the flow to be stagnant, and there was a North-South oriented High-to-Low pressure system over the Korean Peninsula because of this arrangement. The case period was divided into three parts based on the synoptic forcing that was responsible for the heavy snowfall; detailed analyses were conducted for the first and last period. In the first period, a heavy snowfall occurred over the entire Korean Peninsula due to strong updrafts from baroclinic instability and a low pressure caused by potential vorticity located at the mid-troposphere. In the lower atmosphere, a North-South oriented High-to-Low pressure system over the Eastern Korea intensified the easterly airflow and created a convergence zone near the ground which strengthened the upslope effect of the Taebaek Mountain range with a cumulative fresh snowfall amount of 41 cm in the East Coast region. In the last period, the cold air nestled in the Maritime Province of Siberia and Manchuria strengthened much more than that in the first half and extended to the East Sea. The temperature difference between the 850 hPa air and the SST was large and convective clouds developed over the sea. The highest cumulative fresh snow amount of 39.7 cm was recorded in the coastal area during this period. During the entire period, vertically oriented equivalent potential temperature showed neutral stability layer that helped the cloud formation and development in the East Coast. The 2014 heavy snowfall case over the East Coast provinces of Korea were due to: 1) stagnation of the system by blocking pattern, 2) the dynamic effect of mid-level potential vorticity of 1.6 PVU, 3) the easterly air flow from North-South oriented High-to-Low pressure system, 4) the existence of vertically oriented neutral stable layer, and 5) the expansion of strong cold air into the East Sea which created a large temperature difference between the air and the ocean.

• 디지털융복합연구
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• 제10권11호
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• pp.551-558
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• 2012

본 연구는 카이로프랙틱 기법 중 누운 자세에서 시술되어지는 S.O.T category II 골반 블록 중재가 골반의 불안정으로 인한 기울어짐을 회복시킴으로써 이에 따른 어깨통증을 줄이고 복근의 지구력을 향상시킬 수 있는지 알아보고자 한 것이다. 이 실험을 위해 엉치엉덩관절의 불안정을 가지고 있으며 허리의 통증이 있는 총 50명의 참여자가 실험군과 대조군에 각 25명씩 무작위 할당되었다. 실험군은 category II 블록 중재를 받았고, 대조군은 거짓블록 중재를 받았으며, 이들 두 집단을 통해 중재 전, 중재 후, 그리고 중재 2주 후에 복근지구력과 어깨통증을 측정하여 그 결과를 반복측정 이원분산분석법으로 분석하였다. 분석결과 S.O.T category II 골반 블록 중재 후 실험집단에서 복근지구력이 유의한 증가를 보였으며 중재가 끝난 2주 후에도 유지 되었다. 또한 어깨통증의 경우에도 실험집단에서 통증의 감소를 보였으며 역시 중재가 끝난 2주 후에도 유의한 감소를 보였다. 이상의 연구 결과를 종합해 볼 때 S.O.T category II 골반 블록 중재는 골반의 안정성을 유도하여 복근지구력을 증진시키고, 어깨통증을 감소시키며 중재 후에도 지속효과가 있는 것으로 나타남으로, 골반의 불안정성이 원인이 되는 어깨통증이나 복근지구력을 회복시킬 수 있는 중재법으로 활용되어질 수 있을 것으로 사료된다.

• 대한조선학회논문집
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• 제47권2호
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• pp.113-121
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• 2010

Recently, as container ships become larger and faster, rudder cavitations are more frequently observed near the gap between the horn and rudder plates of the ships to cause serious damages to the rudder surface of the ship. The authors already have suggested through a series of model experiments and numerical computations that employment of an appropriate blocking device for gap flow may retard the gap cavitation. For examples, a cam device installed near the outer edges of the vertical gap or a water-injection device combined with a pair of half-round bars installed inside the gap can considerably reduce the gap cavitation. However, it is also found that effective blocking of the flow through the vertical gap results in growth of the cavitation near the horizontal gap instead. In the present study, effectiveness of the simultaneous blocking of the flow through the horizontal and vertical gaps of a horn type rudder in minimizing the damage by gap cavitation is studied. Additional blocking disks are inserted inside the horizontal gaps on the top and bottom of the pintle block and numerical computations are carried out to confirm the combined effect of the blocking devices.

• 전자공학회논문지B
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• 제32B권1호
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• pp.103-109
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• 1995

In this paper, we propose a postprocessing method that neatly removes blocking effect but retains visually important image details and edges. The iterative thresholded lowpass filter is basically a low pass filter whose ouput depends on three variable elements. I.e. iteration number, threshold value and passband width. The threshold value restricts the difference between the output of the proposed filter and the original input independent of the iteration number. With this property, the iterative thresholded lowpass filter can retain most of the image details while smoothing the block boundaries. The other two variable elements, i.e. iteration number and passband width, can determine the convergence speed of the proposed filter. In this paper, we also propose several adaptive filtering techniques based on the iterative thresholded lowpass filter with their simulation results.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2012년도 하계학술대회
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• pp.411-414
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• 2012

영상의 화질을 향상시키기 위한 다양한 방법이 제안되어 왔는데 DCT 영역에서 영상의 화질을 향상시키는 방법은 각 블록별 특성을 효율적으로 이용할 수 있고 JPEG, MPEG 등 표준 압축 기법으로 압축된 영상에 적용이 용이한 장점이 있다. 본 논문에서는 DCT 영역에서 contrast measure를 이용한 화질 향상 기법에서 발생할 수 있는 blocking effect를 크게 감소시키는 lapped transform 영역의 화질 향상 기법을 제안한다. 모의 실험을 통해서 제안하는 기법이 영상의 contrast를 향상시키면서 blocking effect를 크게 감소시키는 것을 보인다.

• 한국해양공학회지
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• 제22권3호
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• pp.1-7
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• 2008

In this study, a mathematical model for flaw with silt protector is proposed that adds a second-order energy loss term in the momentum equation. The three-dimensional numerical model was developed based on mathematical models and verified through comparison with flume test results. Loss coefficients were evaluated through the flume tests and applied to the numerical model. It was found through the investigation of various example cases that the downstream flow pattern was affected mainly by penetration of the silt curtain, not by the approach velocity, and also that the blocking effect of velocity was increased by the increase in mesh density of the silt curtain, below a certain mesh density. The blocking effect did not increase further above a certain mesh density.

• 반도체디스플레이기술학회지
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• 제10권2호
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• pp.57-63
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• 2011

Photovoltaic effect is confirmed in DSSC fabricated under the common conditions. In upper electrodes, validity of ZnO as new TCO material was investigated and an improvement of characteristics in DSSC was tried by control of process conditions at semiconductive powder layer. ZnO thin film showed very high resistivity, therefore efficiency of solar cell was lower than that of conventional ITO-related material. DSSC characteristics was able to improve by thin blocking layer doposited between the TCO and semiconductor layer.

• 한국식품영양과학회지
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• 제27권5호
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• pp.1015-1018
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• 1998

Capsaicin(8-methyl-N-vanillyl-6-nonenamide: CAP) known well as a major compound of not taste in hot pepper, was investigated for the inhibition effect on in vitro nitrosation. CAP(100$\mu$mol) inhibited the formation of N-nitrosoproline(NPRO) and N-nitrosothioproline(NTPRO) by 56% and 26%, respectively. Vanillyl alcohol inhibited the nitrosation of proline by a concentration-dependent manner, and vanillic acid and vanillin were less effective in blocking the nitrosation of proline compared to CAP and anillyl alcohol. The inhibitory effect of NPRO formation by CAP was evaluated to similar with alpha-tocopherol, and vanillyl alcohol was more effective than alpha-tocopherol in blocking the nitrosation of proline. Our results suggested that CAP and its metabolites such as vanillyl alcohol could inhibit endogenous nitrosation in hydrophobic biological environment.

• 약학회지
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• 제36권4호
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• pp.379-389
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• 1992

In order to investigate the effect of nifedipine, $Ca^{+2}$ channel antagoninst, on the action of some drugs participating in blood pressure, this experiment was peformed in rabbits. Nifedipine decreased the pressor actions of norepinephrine, angiotensin and carotid artery clamping, but did not affect the pressor actions of tyramine and depressor actions of acetylcholine and pilocarpine. Nifedipine inhibited the potentiated pressor action of norepinephrine and angiotensin, but did not influence the potentiated pressor action of tyramine in rabbits pretreated with chlorisondamine, ganglionic blocking agent. Nifedipine weakened the potentiated pressor action of norepinephrine, did not affect the pressor action of angiotensin and the potentiated pressor action of tyramine in rabbits pretreated with debrisoquine, sympathetic neuronal blocking agent.

• 대한약리학회지
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• 제12권2호
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• pp.13-19
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• 1976

A fluid extract of Zizyphi Semen was employed in this experiment. The cardiac effects of Zizyphi Semen were examined on isolated rabbits atria and heart in situ of anesthetized cats and rabbits. The adrenergic blocking activity and refractory period of cardiac muscle were measured after administration of this drug. In rabbits and cats the antiarrhythmic action of Zizyphi Semen on atrial and ventricular arrhythmias produced by epinephrine or ouabain was examined. The results were following: 1. Zizyphi Semen produced a decrease in rate and contractile amplitude of the isolated rabbit atria and had a week blocking effect on epinephrine acceleration of atrial movement. 2. Zizyphi Semen effectively abolished the spontaneous arrhythmia occurring in the isolated rabbit atria ana the atrial arrhythmia induced by ouabain. 3. Zizyphi Semen produced a marked prolongation of the refractory period in isolated atrial muscle of rabbit. 4. Zizyphi Semen prevented the induction of ventricular arrhythmia arising from excessive dose of epinephrine in anesthetized rabbits and cats. 5. With regard to the ventricular arrhythmia induced by a continuous infusion of ouabain, Zizyphi Semen exerted suppressive effect and produced a marked prolongation of cardiac arrest time in anesthetized rabbits and cats. From the above results, it may be concluded that Zizyphi Semen is effective against atrial and ventricular arrhythmias. The antiarrhythmic effect of this drug may be the result of direct myocardial depressive and partially adrenergic beta receptor blocking activities including prolongation of the refractory period of cardiac muscle.