• Title/Summary/Keyword: Open ratio

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A Verification Tool of Data Races in Programs with OpenMP Directives (OpenMP 디렉티브 프로그램을 위한 자료경합 검증도구)

  • Kim, Young-Joo;Jun, Yong-Kee
    • Journal of KIISE:Computer Systems and Theory
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    • v.34 no.9
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    • pp.395-406
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    • 2007
  • Races in programs with OpenMP directives must be detected for debugging, because they may cause unexpected result by non-deterministic executions. But, Thread Checker of Intel corporation, a well-known existing tool for detecting the races, is not practical because this tool does not verify the existence of races and is known that the cost for race detection is too big. This paper presents a web-based tool which verify the existence of races with an optimal functionality and performance using the results from the property analysis of OpenMP program as well as the user requirements. Our tool is proved to be practical in the aspect of functionality and performance by experiments using synthetic programs, because the suggested tool can verify the existence of race and shows O(n) as the ratio of time consumption while Thread Checker can not verify the existence of race and shows $O(n^2)$ as the ratio, where n is the number of total accesses.

Large Eddy Simulation of Rectangular Open-Channel Flow using OpenFOAM (OpenFOAM을 이용한 직사각형 개수로 흐름의 LES)

  • Ban, Chaewoong;Choi, Sung-Uk
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.3
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    • pp.833-840
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    • 2014
  • This study presents numerical simulation of turbulent flows in a rectangular open-channel that has a width-to-depth ratio of 2 using the source code provided by OpenFOAM. Large eddy simulations are carried out by solving the filtered continuity and momentum equations numerically. For the non-isotropic residual stress term, Smagorinsky's (1963) model is used. The flow in the open-channel whose width-to-depth ratio is 2, from experiment of Tominaga et al. (1989), is simulated numerically. Simulation results are compared with measured data by Tominga et al. (1989) and Nezu and Rodi (1985) and with LES data by Shi et al. (1999). Comparisons revealed that the model simulates the mean flow and turbulence statistics well. Specifically, the model reproduced the inner secondary currents located at the corner of sidewall and free surface successfully. In addition, the vortical component of turbulence intensity shows bulged contours towards the bottom edge.

The Orthotropic Plate Analysis of Stiffened Plataes with Open Ribs (개단면 리브를 갖는 보강판의 직교이방성 판 해석)

  • Chu, Seok Beom;Kim, Chang Su
    • Journal of Korean Society of Steel Construction
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    • v.14 no.6
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    • pp.701-710
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    • 2002
  • An analysis program using orthotropic plate elements was developed to simplify the analysis of plates stiffened with open ribs and the orthotropic behavior of stiffened plates and the application of this program were evaluated using the sensitivity analysis and the parametric study. The inertial moment ratio, i.e., the ratio of the inertial moment of the rib to that of the plate was defined and the orthotropic behavior of stiffened plates corresponding to the inertial moment ratio was proved by the sensitivity analysis. To evaluate the application of this program, the parametric study for various types of stiffened plates was performed and then the maximum displacement of this study was compared to that of ABAQUS using isoparametric plate elements. The Results of this study agreed well with that of ABAQUS at the particular inertial moment ratio, that is proposed to the limit ratio of the orthotropic plate analysis and the correlative function between the error ratio and the inertial moment ratio was obtained. Therefore, the orthotropic plate analysis of stiffened plates with open ribs could have safe results over the limit ratio and also have good results simply by using the correlative function of this study.

Outcomes of Critical Pathway in Laparoscopic and Open Surgical Treatments for Gastric Cancer Patients: Patients Selection for Fast-Track Program through Retrospective Analysis

  • Choi, Ji Woo;Xuan, Yi;Hur, Hoon;Byun, Cheul Su;Han, Sang-Uk;Cho, Yong Kwan
    • Journal of Gastric Cancer
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    • v.13 no.2
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    • pp.98-105
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    • 2013
  • Purpose: The aim of this study is to investigate the clinical factors affecting on the cure rate by invasive and open surgery for gastric cancer and to establish a subgroup of patients who can be applied by the early recovery after surgery program through this retrospective analysis. Materials and Methods: In this retrospective study, we analyzed 425 patients who underwent gastric cancer surgery between January 2011 and December 2011 and were managed with conventional clinical therapies. This clinical algorithm was made when the patient was in minimally invasive surgery group and discharged from hospital one day faster than them in open surgery group. Results: The completion rate of the clinical pathway was 62.4%. Despite the different applications of clinical pathway, completion rate in minimally invasive surgery group was significantly higher than that of open group (P<0.001). In multivariate analysis, the surgical procedure of minimally invasive surgery (odds ratio=4.281) was the most predictable factor to complete clinical pathway. Additionally, younger patients (odds ratio=1.933) who underwent distal gastrectomy (odds ratio=1.999) without combined resection (odds ratio=3.069) were predicted to accomplish the clinical pathway without any modifications. Conclusions: We concluded that high efficacy of the clinical pathway for gastric cancer surgery was expected to selected patients through retrospective analysis (expected completion rate=85.4%). In addition, these patients would become enrolled criteria for early recovery program in gastric cancer surgery.

The Modified Method of Orthotropic Rigidities for Stiffened Plates with Open Ribs (개단면 리브를 갖는 보강판에 대한 직교이방성 강성의 보정 방법)

  • Chu, Seok Beom;Choi, Young
    • Journal of Korean Society of Steel Construction
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    • v.16 no.2 s.69
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    • pp.191-200
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    • 2004
  • In this paper, the modified method of orthotropic rigidities for stiffened plates with open ribs is proposed to solve the problem of the inaccurate results of the orthotropic plate analysis according to the dimensions of stiffened plates. In analyzing various types of stiffened plates with open ribs using the isotropic and orthotropic plate element, orthotropic plates are found to gave smaller maximum displacements compared to isotropic plates in a range that is smaller than the special rigidity ratio and reversely. Therefore, obtaining a more accurate solution of the orthotropic plate analysis requires modifying the orthotropic rigidities of stiffened plates according to the rigidity ratio. This study presents two modified methods using the displacement function and the displacement ratio. The application of the two methods improves the accuracy of the results of the orthotropic plate analysis, although the modified method using the displacement ratio is better than the method using the displacement function in terms of serviceability and safety. The comparison with the experimental example shows that the proposed modified method improves accuracy. Therefore, the orthotropic plate analysis of stiffened plates with open ribs can achieve more accurate results using the proposed method in this study.

An Experimental Study on Phenomenon of Backfire in H2 HCCI Engine (예혼합 압축착화 수소기관의 역화현상에 관한 실험적 연구)

  • Lee, Jongmin;Lee, Jonggoo;Lee, Kwangju;Lee, Jongtai
    • Transactions of the Korean hydrogen and new energy society
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    • v.26 no.1
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    • pp.28-34
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    • 2015
  • HCCI (Homogeneous Charged Compression Ignition) hydrogen engine has relatively narrower operation range caused by backfire occurrence due to the rapid pressure rising by using higher compression ratio and significant reaction velocity. In this study, to grasp of backfire process and characteristic in the HCCI research hydrogen engine, in-cylinder pressure, intake pressure and backfire limit range are analyzed with compression ratio and intake valve open timing, experimentally. As the result, it is observed that knock is occurred just before backfire occurrence in HCCI hydrogen engine but not spark igntion type, this phenomenon is always the same for the above variables. Also backfire limit range are expanded up to 50% for the more retarding intake valve open timing in this operating conditions.

Comparison of the Effects of Closed Kinetic Chain Exercise and Open Kinetic Chain Exercise According to the Shoulder Flexion Angle on Muscle Activation of Serratus Anterior and Upper Trapezius Muscles During Scapular Protraction

  • Park, Ju-jung;Chon, Seung-chul
    • Physical Therapy Korea
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    • v.24 no.4
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    • pp.11-19
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    • 2017
  • Background: Methods for exercising serratus anterior (SA) and upper trapezius (UT) muscles are important for the recovery of patients with various shoulder disorders, yet the efficacy of closed or open kinetic chain exercises have not yet been evaluated. Objects: The purpose of this study was to compare the activation of the SA and UT muscles during scapular protraction considering both closed and open kinetic chain exercises. Methods: Thirty subjects were randomly divided into experimental groups (closed kinetic chain exercise) and control groups (open kinetic chain exercise) in which scapular protraction was performed at $90^{\circ}$ or $125^{\circ}$ shoulder flexion. Electromyographic activity data were collected from the SA and UT muscles per position and exercise method. Results: Separate mixed 2-way analysis of variance showed significant differences in the activation of the SA (F1,28=6.447, p=.017) and the UT (F1,28=35.450, p=.001) muscles between the groups at $90^{\circ}$ and $125^{\circ}$ shoulder flexion. Also, the SA/UT ratio measures at $90^{\circ}$ and $125^{\circ}$ shoulder flexion significantly differed between the groups (F1,28=15.457, p=.001). That is, the closed chain exercise was more effective than open chain exercise for strengthening the SA muscle and controlling the UT muscle, $125^{\circ}$ of shoulder joint was more effective than $90^{\circ}$. Conclusion: The findings suggest that scapular protraction with shoulder $125^{\circ}$ flexion at the closed kinetic chain exercise may be more effective in increasing SA muscle activation and decreasing UT muscle activation as well as increasing the SA/UT ratio than open kinetic chain exercise.

A Study on Open Innovation and Innovation Performance: Focusing on Manufacturing Industry in South Korea (개방형 혁신과 혁신 성과에 관한 연구: 한국의 제조업을 중심으로)

  • Chung, Do Bum;Kim, Byungil
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.7 no.1
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    • pp.69-76
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    • 2017
  • Recently, it is difficult for a firm to survive and maintain sustainable competitive advantage through internal R&D only, because changes in the environment are very fast and complex. Accordingly, the paradigm of open innovation is gradually emphasized, and the ratio of external R&D has been increasing in various industries. This study analyzed open innovation through Korean Innovation Survey (KIS) data from Science and Technology Policy Institute (STEPI). We confirmed the ratio of open innovation based on firms of the manufacturing industry in South Korea, and examined the relationship between open innovation and innovation performance. This study suggests that open innovation is not a new paradigm that did not exist in the past. While the use of government support programs positively influence innovation performance, the use of external R&D doesn't influence innovation performance due to the difficulties associated with managing it. The results of this study will be used to establish the strategic direction and support the decision making when firms conduct innovation activities in the future.

Polynomial Representation for MAU-Propeller Open Water Characteristics (MAU프로펠러 단독특성의 수식표현)

  • Seo, Jeong-Cheon;Lee, Chang-Seop
    • 한국기계연구소 소보
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    • s.11
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    • pp.95-101
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    • 1984
  • The MAU-series propellers were designed and tested in japan. This report presents the polynomial coefficients of open water Characteristics for each standard MAU-series propellers, obtained by multiple polynomial regression analysis in terms of pitch-diameter ratio and advance coefficient. The limitation of applicability and the accuracy of the regression polynomial are also discussed.

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Estimation of Bearing Capacity for Open-Ended Pile Considering Soil Plugging (폐색정도를 고려한 개단말뚝의 지지력 산정)

  • 백규호
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.03a
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    • pp.397-404
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    • 2002
  • The bearing capacity of open-ended piles is affected by the degree of soil plugging, which is quantified by the IFR. There is not at present a design criterion for open-ended piles that explicitly considers the effect of IFR on pile load capacity In order to investigate this effect, model pile load tests using a calibration chamber were conducted on instrumented open-ended piles. The results of these tests show that the IFR increases with increasing relative density and increasing horizontal stress of soils. The unit base and shaft resistances decrease with increasing IFR. Based on the results of the model pile tests, new empirical relations for base load capacity and shaft load capacity of open-ended piles are proposed. In order to check the accuracy of predictions made with the proposed equations, the equations were applied to the full-scale pile load test preformed in this study, Based on the comparisons with the pile load test results, the proposed equations appear to produce satisfactory predictions.

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