• KIPS Transactions on Computer and Communication Systems
• /
• v.7 no.9
• /
• pp.219-226
• /
• 2018

One of the systematic ways to generate the number of all cases is a combination to construct a combination tree, and its time complexity is O($2^n$). A combination tree is used for various purposes such as the graph homogeneity problem, the initial model for calculating frequent item sets, and so on. However, algorithms that must search the number of all cases of a combination are difficult to use realistically due to high time complexity. Nevertheless, as the amount of data becomes large and various studies are being carried out to utilize the data, the number of cases of searching all cases is increasing. Recently, as the GPU environment becomes popular and can be easily accessed, various attempts have been made to reduce time by parallelizing algorithms having high time complexity in a serial environment. Because the method of generating the number of all cases in combination is sequential and the size of sub-task is biased, it is not suitable for parallel implementation. The efficiency of parallel algorithms can be maximized when all threads have tasks with similar size. In this paper, we propose a method to efficiently collaborate between CPU and GPU to parallelize the problem of finding the number of all cases. In order to evaluate the performance of the proposed algorithm, we analyze the time complexity in the theoretical aspect, and compare the experimental time of the proposed algorithm with other algorithms in CPU and GPU environment. Experimental results show that the proposed CPU and GPU collaboration algorithm maintains a balance between the execution time of the CPU and GPU compared to the previous algorithms, and the execution time is improved remarkable as the number of elements increases.

• Journal of The Geomorphological Association of Korea
• /
• v.15 no.2
• /
• pp.67-83
• /
• 2008

To find out the process of hillslope denudation since the Last Glacial Maximum in Asan area, we conducted the stratiform interpretation and carbon age measurements with the collected samples through trenching in the valley bottom of 'Agol' located in the lower stream of Magok stream. The results are as follows. 11 inorganic and 8 organic matter layers were confirmed at the point of trench MG1 in the subject area, 7 inorganic and 3 organic at the point of trench MG2, and 5 inorganic and 3 organic at the point of trench MG3, respectively. The frequency of hillslope denudation, hillslope mass movement, which had occurred in the unstable environment of back hillslope at the point of MG 1, was 11 times (8 times before about 2,900yrBP, twice in between about 2,900~1,900yrBP, and once after about 1,900yrBP) as a whole. The frequency of moor which had formed in the comparatively stable environment of back hillslope was 9 times (5 times before about 3,000yrBP, twice in between 3,000~2,800yrBP, and once in between 2,200~1,900yrBP) at minimum. The frequency of back hillslope denudation at the point of MG2 was totally 7 times (4 times before about 1,900yrBP and 3 times after about 1,900yrBP) and the moor formations were 3 times (twice before about 1,900yrBP and once after 1,900yrBP). The frequency of back hillslope denudation at the point of MG3 was totally 5 times (3 times before about 1,900yrBP and twice after about 1,900yrBP) and the moor formations were 3 times (twice before about 1,900yrBP and once after 1,900yrBP). The hillslope surrounded by valley bottom of 'Agol' was confirmed as the pile up of various inorganic matters by the mass movement such as sand or sandy gravel in the valley bottom of the subject area, formed not once but several times of denudation. We could know that the hillslope denudation cycle converged to the time period of $10^2{\sim}10^3$ years. These results will be an important basic data for restoring hillslope denudation process near Asan and changing climate of the Late Quaternary Period.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.14 no.1
• /
• pp.151-166
• /
• 2019

New drug development requires 10 to 15 years of long time and more than $ 1 billion in funding, ranging from basic research${\rightarrow}$preclinical medicine${\rightarrow}$clinical medicine${\rightarrow}$product approval${\rightarrow}$sales. Many new drug development bio-venture companies will continue to pursue new drug development with funds secured through listing on the securities market. This study focuses on the impact of the listing on the market of bio-venture companies in the development of new drugs. It is necessary to determine whether the increase in registered patent, preclinical, clinical and technology transfer contracts at the time of listing (D) The results of this study are as follows. We also analyzed whether the registered patent, preclinical, and clinical effects had significant effect on technology transfer contracts at two years after listing and listing. The results of the analysis are as follows. First, Korea's new drug development bio-venture firms increased their registered patents but did not increase their pre-clinical, clinical and technology transfer contracts. Second, at the time of listing and two years after listing, pre-employment has a significant effect on Korea's technology transfer contracts and has a significant effect on overseas technology transfer contracts. However, registered patents and clinics have significant influence on technology transfer contracts. Korea 's new drug development bio-venture firms showed patent increase despite the stock market listing, but pre-clinical, clinical and technology transfer contracts did not increase. In order to strengthen technological commercialization of new drug development bio-venture companies in the future, it is required to establish R & D strategy for efficient use of IPO subscription funds, open innovation through strengthening industry-academia-partnerships, and more sophisticated preclinical and clinical strategy establishment.

• Journal of Korean Society of Transportation
• /
• v.20 no.1
• /
• pp.7-18
• /
• 2002

To activate public transportation service, Bucheon City built Bus Information System based on Beacon type, and operates it for no.22 line. This research analyzes an effect of BIS operations, and mainly it analyzes far reliability evaluation of bus arrival time information and passenger satisfaction about BIS. As results of reliability evaluation of arrival time information service, it is proven to be practically inappropriate to use as arrival time data because it is not only travel time between each bus stop but also previous travel time history data. In order to improve this matter, neural network model was evaluated as the most outstanding one as result of experiment in applying current arrival time Prediction model. This research cannot help limiting for evaluation of operation effect in Bucheon City because there is no Bus Information System based on GPS type in Korea. For the future ITS model city, in the case of building ITS model city based on GPS type, it is possible to compare two systems relatively. In addition to that, fur the consideration of reliability of bus arrival time information, it is required to develop Predictable model and research factors that affect to bus operation.

• Journal of fish pathology
• /
• v.20 no.3
• /
• pp.269-279
• /
• 2007

This study was conducted to investigate the change of antioxidant enzyme activity (catalase and superoxide dismutase) and variation of blood physiology in olive flounder (Paralyticus olivaceus) by hydrogen peroxide (H2O2) treatment. Blood parameters were measured 1, 3 and 5 hours after H2O2 treatment with 0 (control), 100, 300 and 500 ppm for 1 hr. The value of hematocrit was decreased significantly dependently on treatment concentrate and elapsed time in the treatment of H2O2. Hemoglobin concentration in the test groups were lower than that of the control group. Red blood cell value in the test groups were significantly lower compared to that of the control group, but recovered to the level of the control group after 5 hr. Protein concentration was significantly lower compared to that of the control group at 0 and 1 hr, but recovered after 3 hr in 500 ppm treatment group. The superoxide dismutase (SOD) and catalase (CAT) enzyme activities were observed to be increased. Heat-shock protein 70 (HSP70) was significantly increased compared to that of control group in all of the test groups. HSP70 mRNA groups was highly expressed in 500 ppm treatment.

• Journal of Biomedical Engineering Research
• /
• v.24 no.1
• /
• pp.1-8
• /
• 2003

The job of long distance driving is likely to be fatiguing and requires long period alertness and attention, which make considerable demands of the driver. Driving fatigue contributes to driver related with accidents and fatalities. In this study, we investigated the relationship between the number of hours of driving and driving fatigue using heart rate variability(HRV) signal. With a more traditional measure of overall variability (standard deviation, mean, spectral values of heart rate). Nonlinear characteristics of HRV signal were analyzed using Approximate Entropy (ApEn) and Poincare plot. Five subjects drive the four passenger vehicle twice. All experiment number was 40. The test route was about 300Km continuous long highway circuit and driving time was about 3 hours. During the driving, measures of electrocardiogram(ECG) were performed at intervals of 30min. HRV signal, derived from the ECG, was analyzed using time, frequency domain parameters and nonlinear characteristic. The significance of differences on the response to driving fatigue was determined by Student's t-test. Differences were considered significant when a p value < 0.05 was observed. In the results, mean heart rate(HRmean) decreased consistently with driving time, standard deviation of RR intervals(SDRR), standard deviation of the successive difference of the RR intervals(SDSD) increased until 90min. Hereafter, they were almost unchanging until the end of the test. Normalized low frequency component $(LF_{norm})$, ratio of low to high frequency component (LF/HF) increased. We used the Approximate Entropy(ApEn), Poincare plot method to describe the nonlinear characteristics of HRV signal. Nonlinear characteristics of HRV signals decreased with driving time. Statistical significant is appeared after 60 min in all parameters.

• Management & Information Systems Review
• /
• v.35 no.3
• /
• pp.231-247
• /
• 2016

This study, according to the amendment of the Act on External Audit, on the basis of the number of input auditors, the content of auditing, and audit times as additional informations, calculates the average of the samples listed companies with assets of one hundred billion KRW. However, since the actual number of the subject corporations of which asset is 100 billion KRW is small, it is difficult to extract data with reference to this asset size. Therefore, the samples were extended to 50 corporations of which asset is 10% less than 100 billion KRW and other 50 more corporations of which asset is 10% more than 100 billion KRW. As a result, a total of 100 corporations were included as samples. To calculate the average of the audit times, a t-test was performed between the two groups. The result of the t-test showed that there is not a significant difference between the two groups. According to the analytical results of the t-test, the average of the number of input auditors and the average of audit times were calculated with respect to all the 100 samples. A further analysis showed that the average of audit content in the present study was compared with the estimated values in the study of Mun (2016). Although the results of this study may not be the optimal number, they may be used as a fundamental index which may be compared with the audit times and the audit fees in the current audit market where there is not an available reference. In addition, the amendment of the Act on External Audit may enhance the independence of auditors and the transparency of accounting system when compared with the previous system where only the total audit times were disclosed.

• Journal of Korean Society of Environmental Engineers
• /
• v.22 no.6
• /
• pp.1011-1019
• /
• 2000

The purpose of this study is to examine the basis of design condition of existing treatment processes, namely, Extended Aeration Process, Conventional Activated Process, High Rate Aeration Process and Modified Aeration Process, by clarifying the correlations of influent wastewater concentration, hydraulic retention time, food-to-microorganism ratio and sedimentation of sludge, as well as to ascertain the feasibility of design, regardless of the existing design condition. In particular, this study made a priority investigation of hydraulic retention time and sludge sedimentation, because sludge sedimentation is the main factor$^{1)}$ which determines the operating conditions of existing treatment processes. Therefore, it is generally known that in case exceeds the sphere of design presented for each treatment, sludge bulking may occur. The results of Lesperance's test$^{1)}$, which formed the basis of design, showed the sphere of loading without security of sludge sedimentation, as in Fig. 1. The reason for sludge bulking in a certain condition, as above, is due to failure in application of optimum loading corresponding to each retention time by employing a few operating condition, which proved to be consecutively workable after years of trials and failures by Lesperance, for test conditions. However, the result of this test showed that in case of proper maintenance of loading. sludge sedimentation can be ensured under 120 SVI. Therefore, this study suggested hydraulic retention time and its corresponding optimum loading, and identified the hydraulic retention time as a determinant of sludge sedimentation. And. on the basis of these findings, this study suggested the feasiblity of UHR(Ultra High Rate), a new operating process, exceeding several times the applicable loading value of High Rate Aeration Process under one hour retention time which has not yet applied to the existing treatment processes.

• Journal of the Korean Geosynthetics Society
• /
• v.21 no.2
• /
• pp.31-38
• /
• 2022

Recently, irregular torrential rainfall have frequently occurred due to abnormal climate, and landslide damage is increasing. In Korea, more than 70% of the total land is mountainous areas, appropriate measures are needed to prevent landslides by heavy rainfall. When improved soil is applied to the surface of the slope, it is possible to suppress an increase in groundwater level due to rainfall penetration and secure stability of the slope. In this study, the appropriate depth of improved soil that can confirm the increase in groundwater level and secure stability by applying improved soil to the weathered soil slope was studied. A total of three cases were analyzed for the slope of the cross-section: standard slope for weathered soil (1:1.5, 1:1.8, and 1:2.0). For rainfall conditions, referring to the regional frequency probability rainfall provided by the Water resource Management Information System, the increase in groundwater level by stage was confirmed by assuming a 500-year frequency precipitation maximum duration of 48 hours. As a result of the study, in the case of natural slopes, the slope was completely saturated before 48 hours the rainfall duration, and there was a possibility of collapse. the improvement depth in the slope of 1:1.5 was appropriate for more than 1m from the surface regardless of the rainfall duration, and in the the slope of 1:1.8 was appropriate of 1m for more than 36 hours. in the slope of 1:2.0, it was appropriate for that safety when improved soil of 0.5m for rainfall duration 48 hours or more.

• Proceedings of the Korea Association of Crystal Growth Conference
• /
• 1997.10a
• /
• pp.149-154
• /
• 1997

광소자 및 새로운 개념의 전력소자 응용을 위하여 Wide Bandgap 반도체에 대한 관심이 급증되고 있다. 특히 직접천이형인 GaN는 청색 발광소자 응용 및 고출력, 고주파용 전력소자 응용에 이상적인 전자물성을 갖고 있다. 따라서 본 연구에서는 GaCl$_3$와 NH$_3$를 source gas로 하는 CVPE법을 사용하여 (0001) sapphire와 비교하였다. 기판의 증착온도 104$0^{\circ}C$에서 source gas의 III/V flow rate를 2로 분석하여 45분간 성장시킨 경우 그 증착속도는 약 40 $\mu\textrm{m}$/hr 정도였으며, 이 때 XRD을 향상시키기 위하여 증착이전에 기판의 표면에 증착온도에서 NH$_3$를 이용한 nitridation 처리를 하였으며, 그 처리시간이 3분일 때 XRD의 FWHM 특성이 가하여 조사한 결과 363 nm에서 peak가 검출되었다. 본 연구에서는 양질의 GaN 박막성장을 위한 증착조건 인자중 source gas의 flow rate가 가장 중요한 변수임을 적정 온도 범위가 75$0^{\circ}C$ 근처로 조사되었다. 실험과 모사결과의 박막 증착 최적온도의 차이는 GaN 증착시의 반응 Kinetics가 느리기 때문인 것으로 해석된다.