• 아동학회지
• /
• 제20권3호
• /
• pp.231-244
• /
• 1999

This study examined the effects of short and long term playing of video gamer on children's visual parallel processing. All of the 64 fourth grade subjects were above average in IQ. They were classified into high and low video game users. Instruments were a visual parallel processing task consisting of imagery integration items, computers, and the arcade video game, Pac-Man. Subjects were pre-tested with a visual parallel processing task. After one week, the experimental group played video games for 15 minutes, but the control group didn't play. Immediately following this, all children were post-tested by the same task used on the pretest. The data was analyzed by ANCOVA and repeated measures ANOVA. The results showed that relaying short-term video games improved visual parallel processing and that long term experience with video games also affected visual parallel processing. there were no differences between high and low users in visual parallel processing after playing short term video games.

• 대한본초학회지
• /
• 제36권6호
• /
• pp.47-61
• /
• 2021

Objectives : 'Steaming and drying' is a traditional processing method that has been used to produce Suk-ji-hwang (熟地黃; Rehmanniae Radix Preparata) from Ji-hwang (地黃, the fresh root of Rehmannia glutinosa Liboschitz ex Steudel; Rehmanniae Radix). The steaming and drying process, which is proceeded in heating and moisturizing conditions, plays a crucial role in the change of therapeutic effect of Ji-hwang, presumably due to the modification of its chemical constituents. In this article, the chemical influence of the 'Steaming and drying' process was investigated for understanding the underlying mechanism of chemical modification of Ji-hwang. Methods : The articles regarding the modifications of chemical constituents of Ji-hwang during the 'Steaming and drying' process were collected and analyzed to investigate the influence of the processing to Ji-hwang. Results : The results indicated that iridoid glycosides were degraded to their aglycones and sugars, and such degradations occurred faster at a high pressure than at an atmospheric pressure during the process. The contents of catalpol, ajugol, and acteoside were decreased, while those of rehmannioside A and D were slightly increased during the repeated processing. The contents of oligosaccharides, namely sucrose, maltose, raffinose, and stachyose (except for manninotriose), were decreased, while those of monosaccharides, glucose and fructose, were increased by the repeated processing. Conclusions : These results demonstrate that the 'Steaming and drying' process influenced the chemical constituents of Ji-hwang and provide probable basis for the therapeutic modification of Suk-ji-hwang after the processing of Ji-hwang.

• 대한치과기공학회지
• /
• 제43권4호
• /
• pp.175-180
• /
• 2021

Purpose: This study investigates the effect of repeated use of lithium disilicate glass-ceramics on color stability. Methods: In this study, 2 types of lithium disilicate glass-ceramics were used and they were divided into 4 groups after 1st, 2nd, 3rd, and 4th heat pressing. The L^*, a^*, and b^* values of all specimens were measured using the VITA Easyshade Advance 4.0. These values was used to determine the ∆E value and transparency. IBM SPSS Statistics ver. 24.0, a statistical significance level of 0.05 and one-way ANOVA were used for all data. Results: In all groups, the L^* and b^* values were the lowest in the specimens subjected to the 4th heat pressing and the corresponding a^* value was the highest. All specimens showed ∆E values of ≤3.3, indicating color changes that were not visible with the naked eye, and the color difference increased with the number of repeated heat pressing. The transparency of all specimens decreased as the number of repeated uses increased. Conclusion: According to the number of repeated heat pressing, the color difference of Rosetta SP (HASSBIO) was larger than that of IPS e.max Press (Ivoclar Vivadent), but it was clinically acceptable in all groups. Moreover, transparency decreased as the number of heat presses increased in all groups. According to the above findings, the lithium disilicate glass-ceramic has high color stability due to repeated heat pressing, implying that it can be used in clinical settings regularly.

• 한국정보처리학회논문지
• /
• 제5권11호
• /
• pp.2823-2834
• /
• 1998

본 논문에서는 병렬 프로그램을 구성하는 $2^n$개의 타스크 모듈들을 n-차원 하이퍼큐브 다중 컴퓨터에 전체 통신 비용이 최소가 되도록 일대일 매핑하는 문제를 다룬다. 하이퍼큐브에서 최적 매핑을 구한 것은 NP-complete문제이다. 본 논문에서는 먼저 하이퍼큐브 다중 컴퓨터에서의 매핑 문제를 그래프 상에서의 최대 컷세트 집합을 구하는 문제로 변환시키는 그래프 변형 기법을 제안한다. 이러한 그래프 변형 기법을 사용하여 기존의 그래프 이분할 방법을 변형된 그래프 상에 반복 적용함으로써 하이퍼큐브에 타스크 모듈들을 효율적으로 일대일 매핑하는 반복 매핑 알고리즘을 제안한다. 여러가지 타스크그래프 상에서의 실험을 통해, 제안된 반복 매핑 알고리즘이 기존의 greedy나 recursive 매핑 알고리즘들 보다 성능이 우수함을 보인다. 특히 제안된 알고리즘은 하이퍼큐브-isomorphic, 메쉬등과 같은 정형 그래프 상에서 성능이 우수하며 거의 모든 정형 그래프에서 최적 매핑을 찾음을 보인다.

• Safety and Health at Work
• /
• 제14권3호
• /
• pp.303-308
• /
• 2023

Background: Occupational workers at altitudes are more prone to falls, leading to catastrophic outcomes. Acrophobia, height-related anxiety, and affected executive functions lead to postural instabilities, causing falls. This study investigated the effects of repeated virtual height exposure and training on cognitive processing and height-related anxiety. Methods: Twenty-eight healthy volunteers (age 20.48 ± 1.26 years; mass 69.52 ± 13.78 kg) were recruited and tested in seven virtual environments (VE) [ground (G), 2-story altitude (A1), 2-story edge (E1), 4-story altitude (A2), 4-story edge (E2), 6-story altitude (A3), and 6-story edge (E3)] over three days. At each VE, participants identified occupational hazards present in the VE and completed an Attitude Towards Heights Questionnaire (ATHQ) and a modified State-Trait Anxiety Inventory Questionnaire (mSTAIQ). The number of hazards identified and the ATHQ and mSTAIQ scores were analyzed using a 7 (VE; G, A1, A2, A3, E1, E2, E3) x 3 (DAY; DAY 1, DAY 2, DAY 3) factorial repeated measures analysis of variance. Results: The participants identified the lowest number of hazards at A3 and E3 VEs and on DAY 1 compared to other VEs and DAYs. ATHQ scores were lowest at G, A1, and E1 VEs. Conclusion: Cognitive processing is negatively affected by virtual altitudes, while it improves with short-term training. The features of virtual reality, such as higher involvement, engagement, and reliability, make it a better training tool to be considered in ergonomic settings. The findings of this study will provide insights into cognitive dual-tasking at altitude and its challenges, which will aid in minimizing occupational falls.

• 한국정보처리학회논문지
• /
• 제7권1호
• /
• pp.313-320
• /
• 2000

PEM 알고리즘은 패널티 함수가 초월함수 형태일 때에는 반복알고리즘을 전개할 수 가 없다. 하지만, OSL 알고리즘은 복잡한 초월함수 형태의 패널티 함수가 주어지더라도 쉽게 반복 알고리즘이 유도되는 장점을 갖는다. 그러나 이 알고리즘은 패널티 로그-우도를 증가시키는 평활상수의 수렴영역이 제한적이어서 디지털 화상복원시 다양한 평활상수 값을 부여할 수 없기 때문에 최적의 복원화상을 얻을 수 가 없다. 본 논문에서는 OSL 알고리즘의 단점을 해결하기 위해서, 수렴 허용 범위가 확대된 평활상수를 갖는 알고리즘을 제시하고 그 수렴성질을 밝히며, 화상실험을 통해 제안된 알고리즘의 유용성을 밝힌다.

• 한국레이저가공학회지
• /
• 제17권3호
• /
• pp.15-18
• /
• 2014

In this paper, we studied a machining method using a diffractive beam splitter (DBS) and multi- pulse repeated radiation for breathable film. We fabricated micro-grooves on polypropylene (PP) films using multi-pulse radiation and one-shot radiation (radiating pulses at once) and a DBS. In the result, width and depth of the PP film using multi-pulse repeated radiation were more precisely controllable. Therefore, this method can be applicable to in manufacturing breathable film precisely at a high speed.

• 전기학회논문지
• /
• 제59권8호
• /
• pp.1489-1496
• /
• 2010

A feed forward differential architecture of analog PRML decoder is investigated to implement on analog parallel processing circuits. The conventional PRML decoder performs the trellis processing with the implementation of single stage in digital and its repeated use. The analog parallel processing-based PRML comes from the idea that the decoding of PRML is done mainly with the information of the first several number of stages. Shortening the trellis processing stages but implementing it with analog parallel circuits, several benefits including higher speed, no memory requirement and no A/D converter requirement are obtained. Most of the conventional analog parallel processing-based PRML decoders are differential architecture with the feedback of the previous decoded data. The architecture used in this paper is without feedback, where error metric accumulation is allowed to start from all the states of the decoding stage, which enables to be decoded without feedback. The circuit of the proposed architecture is simpler than that of the conventional analog parallel processing structure with the similar decoding performance. Characteristics of the feed forward differential architecture are investigated through various simulation studies.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
• /
• pp.537-539
• /
• 2007

Telemetry processing system requires minimum bit transition level in data streams to maintain a bit synchronization while receiving telemetry signal. PN code has a capability of providing the bit transition and is widely used in the packet communication of CCSDS. CCSDS PN code that generator polynomial is $h(x)=x^{8}+x^{7}+x^{5}+x^{3}+1$, and the random bit sequence that is generated from this polynomial is repeated with the cycle of 255 bits. As the resolution of satellite image increases, the size and transmission rate of data increases. To process of huge and bulky size of satellite image, the speed of CCSDS PN Processing is very important. This paper introduces the way of improving the CCSDS PN Processing speed through processing 128 bits at one time using the feature of cyclic structure that repeats after first 255 bytes by grouping the random bit sequence with 1 byte and Intel Streaming SIMD Extensions 2. And this paper includes the comparison data of processing speed between SSE2-applied implementation and not-applied implementation, in addition, the measured value of speed improvement.

• 한국축산식품학회지
• /
• 제20권1호
• /
• pp.36-43
• /
• 2000

$\beta$-cyclodextrin adsorption and saponification methods were applied to isolate and purify cholesterol from the by-product of the low-cholesterol egg yolk product. They by-product was prepared from processing low-cholesterol egg yolk followed by extracting with chloroform to remove $\beta$-cyclodextrin and concentrated to 3,069 mg% cholesterol. When $\beta$-cyclodextrin method between two purification methods was applied, 50% ethanol as a solvent showed higher cholesterol concentration of 5.82% rather than the other solvents. Repeated purification of 3 times could not improve the cholesterol concentration significantly(p<0.05). In case of purification using saponification method, hexane as a solvent for extraction of unsaponificated materials was more efficient to increase cholesterol concentration than chloroform and ether. 60 times(v/w) saponification solution (95% ethanol:33% KOH = 94:6) of sample weight was most effective to increase the cholesterol concentration of 35.7%. Repeated purification process by saponification method could increase cholesterol concentration to 95.7% by 4 times repetition.