• Tunnel and Underground Space
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• v.18 no.6
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• pp.427-435
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• 2008

In this paper, review was made for the excavation method and optimum bench length for unstable tunnel face in case of rock classification type V in order to make the best use of in-situ bearing capacity. 3D FEM analyses were performed to investigate the influences on the tunnel face and adjacent area with regard to the pattern and number of bolts when face bolts were used as a supplementary measure. As a result of this study, full section excavation method with sub-bench is effective in reducing the displacement greatly due to early section closure. Displacement-resistant effects in accordance with the bolting patterns are grid type, zig-zag type and then circular type in order of their effect. And horizontal extrusion displacement of tunnel face reduces as the number of bolts increase. A grid type face bolt covering $1.5m^2$ of tunnel face could secure the face stability in case of full section excavation method with sub-bench.

• Journal of the Korea Convergence Society
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• v.6 no.4
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• pp.105-111
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• 2015

Most of the software development is determined by the hard skills of project participants and capacity management and operations. However, failure of the current software development is very high. Since the development of the exploration of human psychology continues, the study that there is an association between the preferences of personality and work preference has been actively conducted. It is found out that there is a relationship of preferences in MBTI, the test tool of psychological typology, and those for the work of the ICT engineers tuned to the software development cycle. By using the information on the soft skills associated with software development for the psychological typology, it can be understood the preference of the software development process. In this paper, we develop a program for software development process to allow personality type to be classified with using the soft skills to find ways to improve education and collaboration capabilities of ICT engineers.

• Journal of KIISE:Software and Applications
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• v.27 no.3
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• pp.266-274
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• 2000

Medical image segmentation, which is essential in diagnosis and 3D reconstruction, is performed manually in most applications to produce accurate results. However, manual segmentation requires lots of time to segment, and is difficult even for the same operator to reproduce the same segmentation results for a region. To overcome such limitations, we propose a convenient and accurate semiautomatic segmentation method. The proposed method initially receives several control points of an ROI(Region of Interest Region) from a human operator, and then finds a boundary composed of a minimum cost path connecting the control points, which is the Live-wire method. Next, the boundary is modified to overcome limitations of the Live-wire, such as a zig-zag boundary and erosion of an ROI. Finally, the region is segmented by SRG(Seeded Region Growing), where the modified boundary acts as a blockage to prevent leakage. The proposed User-steered balloon method can overcome not only the limitations of the Live-wire but also the leakage problem of the SRG. Segmentation results of thigh muscles of the Visible Human are presented.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.11
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• pp.933-940
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• 2016

A comparative study between a wind tunnel test and an XFOIL simulation looking at the aerodynamic performance of the airfoil for MW-class wind turbine was conducted for validation in the design stage. Tests are carried out for 21% and 30% thickness-ratio airfoils developed for 5 ~ 10 MW offshore wind turbine and the results are compared with the output from the XFOIL simulation at Reynolds number $1.0{\times}10^7$. The test is performed at a free-stream velocity of 50 m/s, corresponding to a Reynolds number of $2.2{\times}10^6$ based on the chord. Surface roughness is simulated using a zig-zag tape. Discrepancies between the results of the test and the XFOIL analysis are found, however, meaningful data for surface pressure distribution, basic performance and surface roughness effect are obtained from the tests, while useful lift-to-drag ratio data is found by the XFOIL simulation.

• Journal of the Korean Chemical Society
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• v.42 no.6
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• pp.679-695
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• 1998

A series of ${\alpha}{\omega}-bis[4-(4'-(S)-(+)-2-methylbutylbiphenyl-4-carboxy)phenoxy]alkanes$, were synthesized, and their thermal and liquid crystalline properties were studied. The chain length of the central polymethylene spacers, x, of the chiral twin compounds was varied from 3 to 12. These compounds were characterized by elemental analysis, IR and NMR spectroscopy, differential thermal analysis (DSC), and crosspolarized microscopy. All compounds were found to be enantiotropic liquid crystalline, and the values of melting $(T_m)$ and isotropization temperature $(T_i)$ as well as ${\delta}H_I$ and ${\delta}S_I$ decreased in a zig-zag fashion, revealing the so called odd-even effect as x increased. Their mesomorphic properties fell into four categories depending upon x; (a) compounds with x=3, 4 and 5 formed only a cholesteric phase on heating, while on cooling they went through two transitions of isotropic (I)-to-cholesteric (Ch) and Ch-to-smectic $A\;(S_A)$ phases before crystallization. (b) compounds with x=6, 8 and 10 exhibited only a cholesteric phase both on heating and on cooling. (c) compounds with x=7 and 9 went through three transitions of crystal $(C)-to-S_A,\;S_A-to-Ch,$ and Ch-to-I phases on heating while on cooling they went through four transitions of I-to-Ch, $Ch-to-S_A,\;S_A-to-Smectic\;C\;(S_C),\;and\;S_c-to-C$ phases in that order, and (d) compounds with x=11 and 12 went reversibly through four transitions of $C-to-S_C,\;S_C-to-S_A,\;S_A-to-Ch,$ and Ch-to-I phases.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.1
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• pp.140-148
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• 1999

Experiments on flame spread in an one-dimensional droplet array up to supercritical pressures of fuel droplet have been conducted In normal gravity and microgravity. Evaporating process around unburnt droplet is observed through high-speed Schlieren and direct visualizations in detail, and flame spread rate is measured using high speed chemiluminescence images of OH radical. Flame spread behaviors are categorized into three: flame spread is continuous at low pressures and is regularly intermittent up to the critical pressure of fuel. flame spread is irregularly intermittent and zig-zag at supercritical pressures of fuel. At atmospheric pressure, the limit droplet spacing and the droplet spacing of maximum flame spread rate in microgravity are larger than those in normal gravity. In microgravity, the flame spread rate with the increase of ambient pressure decreases initially, takes a minimum, and then decreases after taking maximum. This is so because the flame spread time is determined by competing effects between the increased transfer time of thermal boundary layer due to reduced flame diameter and the reduced ignition delay time in terms of the increase of ambient pressure. Consequently, it is found that flame spread behaviors in microgravity are considerably different from those in normal gravity due to the absence of natural convection.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.29 no.1
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• pp.71-76
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• 2005

Many sea accidents such as collisions and groundings of vessels were occurred due to the lack of sufficient manoeuvring capability of vessels. Therefore IMO adopted 'The interim standards of ship manoeuvrability by Resolution A.751(18) and the standards have been applied to vessels of 100m or more in length and all chemical tankers and gas carriers regardless of the length, which were constructed on or after 1 July 1994. The IMO manoeuvrability standards are divided into three kinds as bellows; (1) Turning capability standards : Estimated values in design stage are to be certified by turning circle test of the actual vessel. (2) Course keeping quality standards : Estimated values in design stage are to be certified by $10^\sqsubset\;and\;20^\sqsubset$ Zig-Zag tests of the actual vessel. (3) Shortest stopping distance standards : Estimated values in design stage are to be certified by the shortest stopping distance tested by the actual vessel. In this paper, the authors computed the values of the manoeuvring standards of several vessels from their original design and compared them with those results from experiments of the model ships and also examined the values and concluded about the validity of IMO Manoeuvrability standards.

• Korean Journal of Plant Resources
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• v.10 no.2
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• pp.183-187
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• 1997

This study was carried out to find the growth characteristics and content of sarsasapogenin in different plant parts of Anemarrhena asphodeloides Bunge. Five native-cultivars were collected and evaluated for several agronomic traits. The collected native-cultivars were classified into two seed-attached peduncle and vegetative propagation types. Seed-attached peduncle lines were predominance of growth traits than vegetative propagation. For the content of sarsasapogenin in each part was investigated, BuOH extarct of 'timo' was developed on silica gel 60G plate using elution solvent($CHC1_2$: Methyl ethyl Ketone : EtOH = 11 : 2 : 0.5). The developed plate were examined using Dual Wavelength Zig - Zag using. Content of sarsasapogenin in main root and lateral root were respectively 1.67mg/g and 1.31mg/g.

• Journal of the Korean Society of Clothing and Textiles
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• v.3 no.2
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• pp.1-7
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• 1979

본 연구의 목적은 여러 증류 솔기의 내연성을 Oxygen Index Test를 통해서 알아봄으로서 내연가공을 한 옷에 가장 이상적인 솔기의 종류를 제시하는 데 있다. 이 목적을 위해서 6가지 종류의 솔기를 내연가공한 옷감으로 만들어 실험하였으며 솔기 종류 이외의 변인으로는 솔기제작에 사용된 실(내연가공한 실과 일반 면사)과 세탁회수가 포함되었다. 솔기의 종류는 (1) 뉜솔(FF) (2) 가름솔에 zig-zag로 시접처리 (PZ) (3) overlook stitch로 박은 솔기(OL) (4) serger로 박은 솔기 (SG), (5) 내연가공한 binding을 사용한 쌈솔(TB) (6) 내연가공하지 않은 binding 을 사용한 참솔(UB) 등이였다. 실험 결과에 의하면 솔기 종류에 따라 O.I. value에 상당히 유의한(p<0.001) 차이가 있었으며, 실의 종류에 따라서도 상당히 유의한(p<0.001) 차이가, 세탁 회수에 따라서도 유의한(p<0.05) 차이가 나타났다. 또한 솔기 종류와 세탁, 솔기 종류와 실의 종류 사이에도 상당히 유의한(p<0.001) 상호작용이 있는 것으로 밝혀졌다. Newman-Keuls 겅증에 의하면 TB, FF, OL 사이에는 유의한 차이가 없으며 이들은 PZ, SG(내연가공하지 않은 실), UB보다 훨신 높은(p<0.01) 내연성을 보였다. SG의 경우 내연가공하지 않은 실을 사용했을 때는 PZ보다도 낮은 O.I. Value를 보였으나 내연가공한 실을 사용했을 때는 FF나 TB 만큼 높은 O.I. 결과가 나타났다. 또한 TB는 위의 솔기 중에서 가장 높은 O.I.를, UB는 가장 낮은 O.I.를 보임으로서 binding의 중요성을 나타냈다. 위의 결과로서 SG, FF, TB가 내연가공에 바람직한 솔기로 나타났으나 TB는 구성과정이 복잡하여 대량 생산에는 많이 사용되지 않으며 SG는 실의 내연가공 여부에 대한 규제가 필요한 것으로 나타났다. 또한 PZ나 UB, SG(일반 실사용)는 내연가공한 옷생산에 사용되지 않는 것이 타당하겠다.

• Archives of Plastic Surgery
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• v.33 no.4
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• pp.485-490
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• 2006

Purpose: As the traditional treatment of the Wassel's type I or II of bifid thumb, Bilhaut-Cloquet, has always been the standard method despite several disadvantages such as tearing of the finger nail, injuries of the growth plate, joint instability, and long visible scarring. To overcome these drawbacks, we applied a modified Bilhaut-Cloquet Method. Methods: The subjects used for the this study were 10 of 20 patients evaluated. The patients underwent modified methods under every type of Wassel's classification. We designed a central wedge Zig-Zag incision and removed the nail and bony tissues in the remaining digit, but not soft tissue if possible, and transferred the ligaments, tendons, and soft tissue to the remaining thumb from the extra digit. We evaluated the patients' lack of extension, the total ROM of the MP and IP joints, the ROM of IP joints, and the lateral deviations of the reconstructed thumb. Results: The results were encouraging, with all patients showing a good functional and aesthetic outcome. Conclusion: The modified method proved a very effective procedure in the treatment of bifid thumb in all types, especially types I or II.