A Radically Assembled Design-Engineering Education Program with a Selection and Combination of Multiple Disciplines

A radically assembled design-engineering program in the school of Design and Human Engineering (DHE) at Ulsan National Institute of Science and Technology (UNIST), newly founded in 2009, is presented. The most distinctive feature in DHE is that all students are required to select two disciplines for their major among three major disciplines, which are; (i) Integrated Industrial Design, (ii) Affective and Human Factors Engineering, and (iii) Engineering and Systems Design. The DHE's major system of the new design-engineering program was developed to foster the next generation designers and engineers, having talent in not only creative ideation but also systematic realization. In this paper, we first describe the founding background, educational rationale and curriculum structure. The curriculum includes students' selective curriculum paths based on their talent and aptitude; collaborative education structure as well as multidisciplinary team-based project courses taught by groups of instructors from different disciplines. Then, the new design-engineering education program is assessed in both quantitative and qualitative ways. The first step of the research is to assess the students' core competencies required in design-engineering combined program by using K-CESA (Korea Colligate Essential Skill Assessment) with 32 students enrolled in DHE. A phenomenological study is also conducted to understand the problems in the current program via in-depth interviews with representative students in DHE. Also, a creative trans-disciplinary short course for students from other universities with various majors (e. g., engineering and design) was offered and tested to evaluate the combined educational system. Finally, we propose the direction for curriculum improvement and follow-up assessment plans, including assessments for students and faculty.open0

Application of reliability design methods to Donghae harbor breakwater

Reliability design methods have been developed for breakwater designs since the mid-1980s. The reliability design method is classified into three categories depending on the level of probabilistic concepts being employed, i.e., Level 1, 2, and 3 methods. Each method gives results in different forms, but all of them can be expressed in terms of probability of failure so that the difference can be compared among the different methods. In this study, we apply the reliability design methods to the stability of armor blocks and sliding of caissons of the breakwater of Donghae Harbor located in the east coast of Korea, which was constructed by traditional deterministic design methods to be damaged in 1987 and reinforced in 1991. Analyses are made for the breakwaters before the damage and after the reinforcement. The allowable probability of failure of a Tetrapod armor layer of 50 years lifetime is proposed as 40% for existing stability formulas, whilst that for caisson sliding as 20% with the failure criterion for the cumulative sliding distance over the lifetime of 0.1 m. The probability of failure before the damage is much higher than the allowable value for both stability of armor blocks and sliding of caissons, indicating that the breakwater was under-designed. The probability of failure for the reinforced breakwater is lower than the allowable value, indicating that the breakwater became stable after the reinforcement. On the other hand, the results of different reliability design methods were in fairly good agreement, confirming that there is not much difference among the different methods.author's final versio

Calculation of partial safety factors of breakwater armor stones considering correlation between wave height and wave steepness

author's final versionIn the calculation of partial safety factors of breakwater armor stones, it has been assumed that all the design variables are independent one another. However, some of them are not independent but are correlated each other. In the present study, the partial safety factors are calculated by considering the correlation between wave height and wave steepness. Smaller partial safety factors and smaller armor weight are obtained if the correlation is taken into account. The reduction becomes prominent as the probability of failure decreases (or the design armor weight increases). The correlation between wave height and steepness in real sea is also estimated by using the wave hindcasting data along the Korean coast

Extended Boussinesq Equations for Rapidly Varying Topography

author's final versionWe developed a new Boussinesq-type model which extends the equations of Madsen and Sørensen (1992) by including both bottom curvature and squared bottom slope terms. Numerical experiments were conducted for wave reflection from the Booijs (1983) planar slope with different wave frequencies using several types of Boussinesq equations and extended mild-slope equation. Madsen and Sørensens model results are accurate in the whole slopes in shallow waters but inaccurate in intermediate water depths. Nwogus (1993) model results are accurate up to 1:1 (V:H) slope but significantly inaccurate for steep slopes. The present model results are accurate up to the slope of 1:1 but somewhat inaccurate for very steep slopes. Further, numerical experiments were conducted for wave reflections from a ripple patch and also a Gaussian shaped trench. For the two cases, the results of Nwogus model and the present model are accurate because these models include the bottom curvature term which is important for the cases. However, Madsen and Sørensens model results are inaccurate because this model neglects the bottom curvature term

Extended mild-slope equation for random waves

author's final versionA time-dependent extended mild-slope equation is derived from the elliptic equation of Chamberlain and Porter (1995) using the Taylor series technique. Numerical tests are made on a horizontally one-dimensional case for regular waves over sloping beds and for both regular and irregular waves over a ripple patch. Numerical results prove that the proposed model gives accurate results for both regular and irregular waves over rapidly varying topography

Generation of random waves in time-dependent extended mild-slope equations using a source function method

We develop techniques of numerical wave generation in the time-dependent extended mild-slope equations of Suh et al. (1997) and Lee et al. (2003) for random waves using a source function method. Numerical results for both regular and irregular waves in one and two horizontal dimensions show that the wave heights and the frequency spectra are properly reproduced. The waves that pass through the wave generation region do not cause any numerical disturbances, showing usefulness of the source function method in avoiding re-reflection problems at the offshore boundary.author's final versio

Internal generation of waves: Delta source function method and source term addition method

author's final versionIn this study, we investigate two internal wave generation methods in numerical modeling of time-dependent equations for water wave propagation, i.e., delta source function method and source term addition method, the latter of which has been called the line source method in literatures. We derive delta source functions for the Boussinesq type equations and extended mild-slope equations. By applying the fractional step splitting method, we show that the delta source function method is equivalent to the source term addition method employing the energy velocity. This suggests that the energy velocity should be used rather than the phase velocity for the transport of incident wave energy in the source term addition method. Finally, the performance of the delta source function method is verified by accurately generating nonlinear cnoidal waves as well as linear waves for horizontally one-dimensional cases

Epidural Blood Patch for the Treatment of Abducens Nerve Palsy due to Spontaneous Intracranial Hypotension -A Case Report-

Intracranial hypotension is characterized by a postural headache which is relieved in a supine position and worsened in a sitting or standing position. Although less commonly reported than postural headache, sixth nerve palsy has also been observed in intracranial hypotension. The epidural blood patch (EBP) has been performed for postdural puncture headache, but little is known about the proper timing of EBP in the treatment of sixth nerve palsy due to intracranial hypotension. This article reports a case of sixth nerve palsy due to spontaneous intracranial hypotension which was treated by EBP 10 days after the onset of palsy