• Korean Journal of Culture and Social Issue
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• v.12 no.1
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• pp.35-54
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• 2006

This study analysed the effect of music tempo on young drivers' driving speed. 23 male college students under age 26 were randomly assigned to one of three music conditions as follows; No Music, Slow Music and Fast Music. Every subject's travel time(sec) and driving speed(Km/h) was recorded while they were driving a computer-based driving simulator. As the results of this study, we found that 1) the fast music group's mean of travel time was the shortest and also, 2) their mean of driving speed was the fastest. The effect of music tempo on driving speed can be explained as a biological mechanism, same as the effect on our heart-beat rate or intensity of physical exercising. This result shows us that listening musics while driving can affect the driving speed instead of the driver's physical condition.

• Journal of Korean Society of Transportation
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• v.28 no.2
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• pp.111-121
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• 2010

DHV (Design-Hour Volume) for the estimation of number of lanes is determined by design-hour factor (K). The design-hour factor is defined as the proportion between the 30th highest hourly volume and AADT and determines the level of road planning. However, the K-factor estimated by an existing method has a problem because the hourly volumes on holiday and weekend appear in the relatively low rank in real world in spite of expected high volumes. To improve this problem, this study make use of the concept of traffic demand in estimating the design-hour factor. After the congested hourly volumes transfer to traffic hourly demand, the K-factors are estimated on urban expressways and are compared to the existing K-factors. It is perceived that the new K-factors have more realistic values due to utilizing the traffic demand. reflecting the congested flow.

• Food Industry
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• s.94
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• pp.37-40
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• 1988

1) 본 연구에서 시료로 선정한 충남 서산산 건강(dry ginger)은 수분이 $9.4\%$, 회분이 $8.7\%$ 그리고 alcohol에 의한 추출량이 약 $9\%$이다. 이는 선진국에 채택사용하고 있는 건강의 규격기준에 의하면 양호하다. 2) Non- flavor물질의 추출을 최소화하고 특히 증류과정에서 유효성분 손실을 최소화 할 수 있고, 엑기스내의 용매 잔류량이 인체에 유해하지 않고 추출효율을 높일 수 있는 용매는 ethyl alcohol이다. 3) 널리 사용하고 있는 관류추출(percolation)의 성능을 분석하고 이의 개선방안을제시하였다. - 추출효율을 높이기 위하여 건강(dry ginger)의 입자를 작게하면 압력강하가 증대되어순환되는 용액의 유속을 제어하기가 힘들다. - 입자가 작을 시에는 유체의 흐름이chan-nelling현상을 나타낸다. - 위와 같은 조건에서는 물질 전달속도가 느리므로 추출효율을 증대시킬 수가 없다. - 따라서 percolation추출에 사용되는 건강의 입자크기는 30mesh크기 이상이어야 운전조작이 용이하나 추출효율이 낮으므로, 추출시간 6시간에 회수된 생강엑기스양은 약 $2.5\%$이다. 4) percolation추출의 단점을 보완하기 위하여 기계적교반 추출을 선택하여 다음과 같은 개선점을 찾았다. - 교반형 추출에서는 고 - 액분리시 cake 저항에서 문제가 야기되지 않는 범위까지 건강의 입자를 작게할 수 있으므로 추출효율을 크게 향상시킬 수 있었다. 즉, 작게 분쇄된 건강(30mesh통과$90\%$)을 대상으로 추출시간 3시간에 $7\%$의 회수율로 증대시켰다. 최적 운전조건은 다음과 같다. 건강시료:1kg 시료크기:-30mesh$90\%$ 용매:ethyl alcohol 3$\iota$ 교반속도:900r.p.m 추출온도:상온($15\~25^{\circ}C$) 추출시간:3시간 일차 추출조건과 동일하게 하여 얻어진 엑기스의 수율이 $2\~2.5\%$이므로 총엑기스의 수율은 건강(dry ginger)무게기준으로 $8.5\~9.5\%$이었다. 5) 교반추출의 효율이 개선되었다 하더라도 추출물의 분리가 용이하여야만 공정의 이용이 가능하다. 그러므로 교반추출후 고 - 액분리를 위하여 정압여과 장치를 이용하여 여과시 cake의 평균 비저항을 얻었으며, 이의 값은 $4.31\times10^8cm\;/\;gr$으로서 여과에는 어려움이 없다는 것을 의미한다. 따라서 추출속도와 효율이 상대적으로 우수한 교반형 추출기의 가능성을 예시할 수 있음을 알 수 있었다. 6) 추출물을 농축과정에서 휘발성 oil의 손실을 최대로 줄이기 위해서는 단순증류를 하지 말고 분별증류를 수행하여야 하며, gingerol과 같은 중요성분의 열분해 반응을 억제하기 위해서는 열전달 효율을 증대시켜 증류조작을 원활히 수행하여야 하므로, still내의 농축물을 계속 교반시켜야 하며 감압상태에서 증류온도는 $40\~50^{\circ}C$로 유지시키는 것이 가장 바람직하다. 7) Ethyl alcohol로 추출된 엑기스내의 수분이나 회분함량은 외국산 제품에 비하여 약간 낮고, 반면에 조지방 및 조단백 성분의 함량은 약간 높게 나타나고 있어 대체적으로 본 연구에서 얻어진 엑기스내의 비풍미성분(non- fla-vour component) 함량은 외국산에 비하여 많은 차이가 없다. 8) 수입 외국산에 비하여 국산엑기스(본 연구에서 ethyl alcohol로 추출)내의 무기성분등의 함량은 비교적 낮은 편이다. 9) 건강에서부터 oleoresin을 얻어 paradol을 제거시킨 후 순수한 gingerol을 분리하여 IR과 NMR로 확인한 결과, 국산건강의 엑기스에는 주로 6-gingerol이고 약간의 10-gingerol이 함유된 것으로 나타났다. 10) 순수하게 분리된 gingerol을 열분석(TGA와 DTG)한 결과 약 $75^{\circ}C$에서 gingerol의 열분해 반응이 일어남을 알수 있었다. 11) 건강 분말시료와 엑기스내의 미생물 검사 결과 건강분말에서는 세균수가 많이 존재하는 것으로 나타났으나, 이는 ethyl alcohol로 추출하는 공정 중 대부분의 균들이 사멸된 것으로 나타났다. 12) 관능적 측면에선, 본 연구에서 제조한 엑기스와 수입엑기스를 비교한 결과 생강 특유의 맛은 비슷했으나, 수입엑기스에서는 쓴맛과 톱밥냄새를 느낀다는 결과를 나타내었으며 전체적인 종합적 풍미는 국산 건강엑기스가 좋은 것으로 나타났다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4D
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• pp.679-686
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• 2006

Recently, the city railway in the Seoul Metropolitan Area (SMA) has offered a low quality of service as a passage time, because it was operated slowly. So, the people who live in modern society are not satisfied about passage time, therefore, this study tried to make that the subway in the SMA becomes a more functional and effective wide-area-transportation-network through an express train introduction's method which examined cases from abroad and current system. and then presented how express train could be applied to current system. In a case study, We used the An-San Line and Su-In Line as a examples and developed a schedule which can minimize the delaying time of subway by using Branch & Bound Algorithm. The train operational plan was loaded to consider a railroad siding, Obtained site, and the dispatch interval(three to ten minutes) for the express and local lines and finally, We presented an alternative operational plan which made by those factors.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2D
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• pp.235-242
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• 2008

Due to the lack of judgement in an information processing on road sign, older drivers usually are having a hard time driving than young group. Furthermore, according to increasing in aging population, older drivers in Korea have been growing much faster. That means research for older drivers' characteristics and the number of guide name for road sign should be needed. In accordance with suggestions, this study was carried out the number of guide names for road sign with a variety of ages from the twenties to the seventies. For the sake of this study, statistical verification was conducted to confirm a change of speed, a reading time and a misreading rate with Driving Simulator and Electrooculogram tool. As the results of study, change of speed in the age range has shown that the higher the proportion of age, the lower the rate of velocity. Also reading time in the age range with regression analysis found that the higher the proportion of age, the higher the rate of reading time by 0.106sec. Finally, a binary logistic model was used to find the main factors. As the results, 4 number of guide names for road sign have been the best of them for older driver. The result of this study verified the importance of ideal guide numbers on road sign for older driver and proved itself to be an effective method to determine the road safety for the road signs.

• Journal of Korean Society of Forest Science
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• v.36 no.1
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• pp.26-32
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• 1977

Press drying was used on sapwood and heartwood of oak (Qercus acutissima Carruthers) to find profitable means of drying low grade logs. This study was designed to investigate the process of press drying considering core temperature, current moisture content, drying rate, drying time, final moisture content, dimensional change and drying defects. The drying tests were conducted using 1.5 centimeter thick material at platen temperature of $175^{\circ}C$ and pressure of 35psi. The results were summarized as fallows. 1. Core temperature was divided into three stages of drying characterized by initial heating period, plateau temperature, and period of rising core temperature. Plateau temperature of heartwood material was higher and longer than that of sapwood material. 2. The predicting equation for change in drying rate of sapwood material was log y=-2.7925-0.0811x as function of time. That of heartwood material was log y=-3.3382-0.0468x. 3. Sapwood material reduced the moisture content from 59 to 2.5 percent in 45minutes. Heartwood material reduced the moisture content from 64 to 3.3 percent in 55 minutes. 4. Shrinkage during press drying were 20.4 percent in thickness direction and 2.5 percent in width direction. Recovery on equilibrium conditioning at 65 percent relative humidity and temperature of $20^{\circ}C$. were 11.4 percent in thickness direction and 49.4 percent in width direction. 5. Heartwood material developed severe honeycombing and moderate checking. The sapwood material dried without honeycombing, checking and collapse. All material kept wood flat.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.49 no.1
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• pp.23-28
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• 2012

The performance improvement of the secondary storage is very slow compared to the main memory and processor. The data is loaded from secondary storage to memory for the execution of an application. At this time, there is a bottleneck. In this paper, we propose an Executable Compression Method to speed up the initial loading time of application. and we examined the performance. So we implemented the two applications. The one is a compressor for Execution Binary File. and The other is a decoder of Executable Compressed application file on the Embedded System. Using the test binary files, we performed the speed test in the six files. At the result, one result showed that the performance was decreased. but others had a increased performance. the average increasing rate was almost 29% at the initial loading time. The level of compression had different characteristics of the file. And the performance level was dependent on the file compressed size and uncompress time. so the optimized compression algorithm will be needed to apply the execution binary file.

• Journal of the Microelectronics and Packaging Society
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• v.14 no.3
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• pp.43-49
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• 2007

Thickness of intermetallic compounds and consumption rates of under bump metallurgies (UBMs) were investigated in wafer-level solder bumping with variations of UBM materials and reflow times. In the case of Cu UBM, $0.6\;{\mu}m-thick$ intermetallic compound layer was formed before reflow of Sn solder, and the average thickness of the intermetallic compound layer increased to $4\;{\mu}m$ by reflowing at $250^{\circ}C$ for 450 sec. On the contrary, the intermetallic layer had a thickness of $0.2\;{\mu}m$ on Ni UBM before reflow and it grew to $1.7\;{\mu}m$ thickness with reflowing for 450 sec. While the consumption rates of Cu UBM were 100nm/sec fur 15-sec reflow and 4.50-sec for 450-sec reflow, those of Ni UBM decreased to 28.7 nm/sec for 15-sec reflow and 1.82 nm/sec for 450-sec reflow.

• Journal of Digital Convergence
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• v.12 no.11
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• pp.379-386
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• 2014

In this paper, the processing speed of Grabcut algorithm in order to efficiently improve the GPU (Graphics Processing Unit) for processing the data from the method. Grabcut algorithm has excellent performance object detection algorithm. Grabcut existing algorithms to split the foreground area and the background area, and then background and foreground K-cluster is assigned a cluster. And assigned to gradually improve the results, until the process is repeated. But Drawback of Grabcut algorithm is the time consumption caused by the repetition of clustering. Thus GPGPU (General-Purpose computing on Graphics Processing Unit) using the repeated operations in parallel by processing Grabcut algorithm to effectively improve the processing speed of the method. We proposed method of execution time of the algorithm reduced the average of about 95.58%.

• The Korean Journal of Applied Statistics
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• v.28 no.3
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• pp.393-406
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• 2015

We examine how to model mortality risk using the adaptation of the mean-reverting processes for the two factor model proposed by Cairns et al. (2006b). Mortality improvements have been recently observed in some countries such as United Kingdom; therefore, we assume long-run mortality converges towards a trend at some unknown time and the mean-reverting processes could therefore be an appropriate stochastic model. We estimate the parameters of the two-factor model incorporated with mean-reverting processes by a Metropolis-Hastings algorithm to fit United Kingdom mortality data from 1991 to 2015. We forecast the evolution of the mortality from 2014 to 2040 based on the estimation results in order to evaluate the issue price of a longevity bond of 25 years maturity. As an application, we propose a method to quantify the speed of mortality improvement by the average mean reverting times of the processes.