국내 고속도로의 콘크리트 포장은 줄눈 콘크리트 포장 공법을 주로 적용해 왔으나 잦은 줄눈부 파손으로 인해 최근에는 공용성이 우수한 연속철근 콘크리트 포장(CRCP)을 확대 적용하고 있는 추세이다. CRCP는 우수한 공용성을 가지고 있지만 다량의 철근 사용으 로 인해 초기 시공비가 높은 단점이 있다. 이러한 CRCP의 단점을 보완하고 공용성을 보다 향상시키기 위해 신개념 철근콘크리트 포 장(ARCP)이 개발되었다. 본 연구에서는 ARCP의 공용성 검증을 위해 고속도로 제14호선 함양~울산 구간에 시공된 ARCP와 동일한 구 간에 시공된 CRCP의 균열조사를 수행하였으며 균열형상 및 균열간격 등을 비교 분석하였다. 분석 결과 ARCP에서 발생한 균열은 CRCP와 비교하여 대부분 직선 형상으로 발생하였으며 균열간격도 보다 균일한 것을 확인하였다. 또한, ARCP에서는 좁은 균열간격, 지그재그 균열, 분리균열 등 부적절한 균열의 발생이 매우 적은 것을 확인하였다. 따라서 ARCP의 균열형상 분석 결과로 보아 ARCP 는 CRCP의 우수한 공용성을 보다 향상시킬 수 있는 공법이라는 것을 검증하였다.

신개념 철근콘크리트 포장인 ARCP(Advanced Reinforced Concrete Pavement)는 연속철근 콘크리트 포장인 CRCP(Continuously Reinforced Concrete Pavement)에서 균일하지 않게 발생하는 균열과 다량의 철근 사용으로 인한 높은 시공비를 개선한 기술이다. ARCP 는 고속도로 제1호선 언양~영천 구간에 최초로 시공하였으며 고속도로 제14호선 밀양~울산 구간에도 시공하였다. 이전의 시공 과정 및 초기 공용성을 기반으로 ARCP의 주요 기술 요소인 부분철근과 균열유도장치의 형상을 개선하여 고속도로 제14호선 창녕~밀양 구 간에 적용하여 시공하였다. 기존 균열유도장치는 반달형의 GFRP 재질로 제작되었으며 지지대를 이용하여 설치하였으나 개선된 균열 유도장치는 L형의 철재로 부분철근에 용접된 어셈블리 형태로 제작되어 설치가 간단하다. 기존 부분철근은 2개의 부분철근을 서로 연 결시킨 형상이었으나 개선된 부분철근은 연결부를 두지 않고 독립적인 형상으로 설치하였다. ARCP 시공 이후 초기 현장조사 결과, 균 열유도장치가 설치된 곳에서 적절한 균열이 발생하는 것을 확인하였으며 슬래브 표면 침하도 발생하지 않았다. 따라서 개선된 부분철 근과 균열유도장치를 적용함으로써 ARCP의 시공성 및 공용성을 한층 더 향상시킬 수 있을 것으로 기대된다.

현대사회는 사회, 경제, 정치, 문화적으로 비약적인 발전을 이루었으나, 이러한 발전 속에서 현대인들은 심리적 피로와 함 께 사회적 불만을 심각하게 경험하고 있다. 전국시대라는 혼란 한 시기에 살았던 장자 역시 그러한 사회적 혼란 속에서 삶을 영위했으나, 그는 혼란 속에서도 자유롭고 온전한 삶을 추구하 였다. 장자의 철학은 혼란한 현실로부터의 단순한 도피가 아니 라, 세속의 삶 속에서 인위적인 억압에 구속되지 않고 진정한 정신적 자유를 추구하는 것을 목표로 한다. 그는 이러한 정신 적 자유에 도달하기 위해, 외부로부터 정신이 자유로워질 수 있는 심재(心齋)와 좌망(坐忘)이라는 수련을 제시하였다. 장자 는 이 수련 과정을 통해 물아일체(物我一體)와 무위자연(無爲自 然)의 도(道)를 체득하게 되며, 그 결과로 지미지락(至美至樂)과 천락(天樂)의 경지에 이르게 된다고 보았다. 장자는 이러한 경 지에 도달함으로써 궁극적으로 최고의 쾌락과 자유, 그리고 미 를 획득할 수 있다고 주장한다. 이와 같은 장자의 철학은 현대 건축 공간에도 중요한 영향을 미치며, 시간과 공간, 사용자 간 의 경계가 모호해지는 관계적 무경계성이라는 개념을 통해 현 대 건축에서 나타나는 중첩, 차경, 병치 등의 건축적 기법을 설 명할 수 있다. 이러한 특성을 반영한 현대 건축 공간은 전통과 현대를 아우르는 심미적 특성을 가지며, 이를 통해 전통과 현 대를 통합적으로 이해하는 데 중요한 기여를 한다. 장자의 사 유를 바탕으로 현대 건축 공간을 분석하는 접근은 현시대의 다 양한 건축물에 대한 형이하학적 해석을 넘어서, 공간의 심미적 특성을 깊이 있게 이해할 수 있는 새로운 관점을 제공한다.

We examine a single machine scheduling problem with step-improving jobs in which job processing times decrease step-wisely over time according to their starting times. The objective is to minimize total completion time which is defined as the sum of completion times of jobs. The total completion time is frequently considered as an objective because it is highly related to the total time spent by jobs in the system as well as work-in-progress. Many applications of this problem can be observed in the real world such as data gathering networks, system upgrades or technological shock, and production lines operated with part-time workers in each shift. Our goal is to develop a scheduling algorithm that can provide an optimal solution. For this, we present an efficient branch and bound algorithm with an assignment-based node design and tight lower bounds that can prune branch and bound nodes at early stages and accordingly reduce the computation time. In numerical experiments well designed to consider various scenarios, it is shown that the proposed algorithm outperforms the existing method and can solve practical problems within reasonable computation time.

In this study, we propose an optimal design method by applying the Prefabricated Buckling Restrained Brace (PF-BRB) to structures with asymmetrically rigidity plan. As a result of the PF-BRB optimal design of a structure with an asymmetrically rigidity plan, it can be seen that the reduction effect of dynamic response is greater in the case of arrangement considering the asymmetric distribution of stiffness (Asym) than in the case of arrangement in the form of a symmetric distribution (Sym), especially It was confirmed that at an eccentricity rate of 20%, the total amount of reinforced PF-BRBs was also small. As a result of analyzing the dynamic response characteristics according to the change in eccentricity of the asymmetrically rigidity plan, the distribution of the reinforced PF-BRB showed that the larger the eccentricity, the greater the amount of damper distribution around the eccentric position. Additionally, when comparing the analysis models with an eccentricity rate of 20% and an eccentricity rate of 12%, the response reduction ratio of the 20% eccentricity rate was found to be large.

본 연구는 국내의 세 품종 돼지에 대하여 혈통자료를 이용한 근교계수와 유전체자료를 이용한 근교계수를 분석하고 비교하기 위하여 수행되었다. 분석에 이용된 혈통자료는 듀록, 랜드레이스 및 요크셔 종에서 각각 137,302두, 228,651두와 657,079두였고, 유전체자료의 경우 Illumina Porcine SNP 60K bead chip V2를 이용하여 수집하였으며 세 품종에서 각각 2,567개, 7,594개 및 12,906개의 자료를 이용하였다. 듀록, 랜드레이스와 요크셔에서 혈통자료를 이용하여 추정된 근교계수는 각각 0.04, 0.02 및 0.02였으며, 유전체자료를 이용하여 추정된 근교계수는 각각 0.184, 0.098 및 0.063이었다. 듀록에서 두 근교계수의 상관이 0.466으로 가장 높게 나타났다. 본 연구를 통하여 혈통완성도는 유전체 정보를 이용하여 보완할 수 있음이 확인되었으며, 유전체 정보는 집단의 유전자원 관리에도 활용도가 높아 국내 양돈산업의 근친도 관리에서 중요한 역할을 할 것으로 기대된다.

The effects of annealing on the microstructure and mechanical properties of Al–Zn–Mg–Cu–Si alloys fabricated by high-energy ball milling (HEBM) and spark plasma sintering (SPS) were investigated. The HEBM-free sintered alloy primarily contained Mg2Si, Q-AlCuMgSi, and Si phases. Meanwhile, the HEBM-sintered alloy contains Mg-free Si and θ-Al2Cu phases due to the formation of MgO, which causes Mg depletion in the Al matrix. Annealing without and with HEBM at 500oC causes partial dissolution and coarsening of the Q-AlCuMgSi and Mg2Si phases in the alloy and dissolution of the θ-Al2Cu phase in the alloy, respectively. In both alloys, a thermally stable α-AlFeSi phase was formed after long-term heat treatment. The grain size of the sintered alloys with and without HEBM increased from 0.5 to 1.0 μm and from 2.9 to 6.3 μm, respectively. The hardness of the sintered alloy increases after annealing for 1 h but decreases significantly after 24 h of annealing. Extending the annealing time to 168 h improved the hardness of the alloy without HEBM but had little effect on the alloy with HEBM. The relationship between the microstructural factors and the hardness of the sintered and annealed alloys is discussed.

Radish is an important root vegetable in the world, and many cultivars have been developed with various molecular marker systems to identify these cultivars. Recently developed markers for radish cultivar identification require only 11 primer pairs, but they still use conventional PCR with different annealing temperatures and time-consuming gel electrophoresis. To improve the genotyping method, we applied touchdown PCR with 11 primers with M13 tails among 105 radish cultivars. Touchdown PCR successfully generated amplicons in all 11 M13-tailed primers with a condition of annealing temperature starting from 55℃, decreased by 1°C and 33 cycles at 53°C. The 11 M13-tailed primers followed by fragment analysis produced 71 amplicons, which produced more amplicons than gel electrophoresis that produced 23 amplicons. Especially, simple sequence repeats produced more amplicons, 12 on average, than the other marker types. The present study requires less effort and provides more accurate results compared to genotyping using gel electrophoresis. Besides, a database can be established using digitized genotyping results among radish cultivars.

In this study, a prefabricated buckling brace (PF-BRB) was proposed, and a test specimen was manufactured based on the design formula for the initial shape and structural performance tests were performed. As a result of the experiment, all standard performance requirements presented by KDS 41 17 00 and MOE 2021 were satisfied before and after replacement of the reinforcement module, and no fracture of the joint module occurred. As a result of the incremental load test, the physical properties showed a significant difference in the stiffness ratio after yielding under the compressive load of the envelope according to the experimental results. It is judged necessary to further analyze the physical properties according to the experimental results through finite element analysis in the future.

In the case of a school building, even though it is a regular structure in terms of plan shape, if the masonry infill wall acts as a lateral load resisting element, it can be determined as a torsionally irregular building. As a result, the strength and ductility of the structure are reduced, which may cause additional earthquake damage to the structure. Therefore, in this study, a structure similar to a school building with torsional irregularity was selected as an example structure and the damping performance of the PC-BRB was analyzed by adjusting the eccentricity according to the amount of masonry infilled wall. As a result of nonlinear dynamic analysis after seismic reinforcement, the torsional irregularity of each floor was reduced compared to before reinforcement, and the beams and column members of the collapse level satisfied the performance level due to the reduction of shear force and the reinforcement of stiffness. The energy dissipation of PC-BRB was similar in the REC-10 ~ REC-20 analytical models with an eccentricity of 20% or less. REC-25 with an eccentricity of 25% was the largest, and it is judged that it is effective to combine and apply PC-BRB when it has an eccentricity of 25% or more to control the torsional behavior.

Buckling Restrained Braces can not only express the strength considered at the time of design, but also reduce the seismic load by energy dissipation according to the plastic behavior after yield deformation of the steel core. The physical characteristics and damping effect may be different according to the buckling prevention method of the steel core by the lateral restraint element. Accordingly, in this study, To compare hysteresis characteristics, Specimen(BRB-C) filled with mortar, specimen(BRB-R) combined with a buckling restraint ring and Specimen(BRB-EP) filled with engineering plastics was fabricated, and a cyclic loading test was performed. As a result of the cyclic loading test, the maximum compressive strength, cumulative energy dissipation and ductility of each test specimen was similar. But in case of the cumulative energy dissipation and ductility, BRB-C filled with the mortar specimen showed the lowest. This is considered to be because the gap between the steel core and the reinforcing material for plastic deformation was not uniformly formed by pouring mortar around the core part.

This study proposes an RCS composite damping device that can achieve seismic reinforcement of existing buildings by dissipating energy by inelastic deformation. A series of experiments assessing the performances of the rubber core pad, hysteretic steel slit damping device, and hybrid RCS damping device were conducted. The results showed that the ratios of the deviations to the mean values satisfied the domestic damping-device conformity condition for the load at maximum device displacement in each direction, at the maximum force and minimum force at zero displacement, as well as the hysteresis curve area. In addition, three analysis models based on load-displacement characteristics were proposed for application to seismic reinforcement design. In addition, the validity of the three proposed models was confirmed, as they simulated the experimental results well. Meanwhile, as the shear deformation of the rubber-core pad increased, the hysteretic behavior of super-elasticity greatly increased the horizontal force of the damping device. Therefore, limiting the allowable displacement during design is deemed to be necessary.

In this study, an incremental loading test of the HRS(Hybrid Rubber Slit) damper was additionally performed to define the physical characteristics according to the incremental test results, and an analytical study was performed according to the damping design procedure by selecting an example structure. As a result of performing seismic performance evaluation before reinforcement by selecting a RC structure similar to an actual school structure as an example structure, the story drift ratio was satisfied, but some column members collapsed due to bending deformation. In order to secure the seismic performance, the damping design procedure of the HRS damper was presented and performed. As a result of calculating the amount of damping device according to the expected damping ratio and applying it to the example structure, the hysteresis behavior was stable without decrease in strength, and the story drift ratio and the shear force were reduced according to the damping effect. Finally the column members that had collapsed before reinforcement satisfied the LS Level.

It is effective to apply hybrid damping device that combine separate damping device to cope with various seismic load. In this study, HRS hybrid damper(hybrid rubber slit damper) in which high damping rubber and steel slit plate are combined in parallel was proposed and structural performance tests were performed to review the suitability for seismic performance. Cyclic Loading tests were performed in accordance with criteria presented in KDS 41 17 00 and MOE 2019. As a result of the test, the criteria of KDS 41 17 00 and MOE2019 was satisfied, and the amount of energy dissipation increased due to the shear deformation of the high-damping rubber at low displacement. Result of performing the RC frame test, the allowable story drift ratio was satisfied, and the amount of energy dissipation increased in the reinforced specimen compared to the non-reinforced specimen.

Changes in the mechanical properties and microstructure of an IN 939 W alloy according to the sintering heating rate were evaluated. IN 939 W alloy samples were fabricated by spark plasma sintering. The phase fraction, number density, and mean radius of the IN 939W alloy were calculated using a thermodynamic calculation. A universal testing machine and micro-Vickers hardness tester were employed to confirm the mechanical properties of the IN 939W alloy. X-ray diffraction, optical microscopy, field-emission scanning electron microscopy, Cs-corrected-field emission transmission electron microscopy, and energy dispersive X-ray spectrometry were used to evaluate the microstructure of the alloy. The rapid sintering heating rate resulted in a slightly dispersed γ' phase and chromium oxide. It also suppressed the precipitation of the η phase. These helped to reinforce the mechanical properties.

A typical trade-off relationship exists between strength and elongation in face-centered cubic metals. Studies have recently been conducted to enhance strength without ductility reduction through surface-treatment-based ultrasonic nanocrystalline surface modification (UNSM), which creates a gradient microstructure in which grains become smaller from the inside to the surface. The transformation-induced plasticity effect in Fe-Mn alloys results in excellent strength and ductility due to their high work-hardening rate. This rate is achieved through strain-induced martensitic transformation when an alloy is plastically deformed. In this study, Fe-6%Mn powders with different sizes were prepared by high-energy ball milling and sintered through spark plasma sintering to produce Fe-6%Mn samples. A gradient microstructure was obtained by stacking the different-sized powders to achieve similar effects as those derived from UNSM. A compressive test was performed to investigate the mechanical properties, including the yielding behavior. The deformed microstructure was observed through electron backscatter diffraction to determine the effects of gradient plastic deformation.

게임을 구현하는 동안 주기성을 보장해야될 필요성이 있는 경우가 많이 있다. 예를 들어 많은 경우에 캐릭 터의 충돌은 주기적으로 처리되어야 될 필요성이 있는데 주기적으로 처리하지 못하는 경우 게임에서 충돌 을 감지하지 못하는 경우가 발생할 수 있다. 또한 슈팅 게임에서는 많은 경우에 사용자의 편의를 위하여 특 정 버튼을 누르면 무기를 자동적으로 발사하는 기능을 포함하고 있어 주기적으로 무기를 발사해야될 필요 성이 있다. 한편 유니티를 사용하여 게임을 구현할 때 이러한 주기성을 보장하기 위해서 WaitForSeconds로 지연을 발생시킨 코루틴, InvokeRepeating, FixedUpdate, .NET의 Timers.Timer가 사용될 수 있다. 그러나 이러한 다양한 방법들로 인하여 방법의 선택에 어려움이 있어 연구를 진행하였다. 본 연구에서는 1분 동안 6000번 메서드를 주기적으로 실행하고 주기성과 횟수를 측정하였다. 또한 다양한 환경에서의 실험을 위하여 추가의 모델 렌더링이 없는 경우와 렌더링을 추가한 경우, 다양한 해상도에서 주기성과 메서드 호출 횟수를 모두 측정했다. 실험 결과, 부하가 적은 환경에서는 InvokeRepeating이 가장 6000회에 가까웠으며 부하가 큰 환경 에서는 Timers.Timer가 가장 6000회에 가까웠으며 실행 주기의 편차가 가장 적었다. 이러한 실험들을 통하여 유니티를 통하여 게임을 구현할 때 일정 시간 내에 실행되는 횟수가 중요한 게임에서 성능 부하가 크지 않 은 경우 InvokeRepeating을, 성능 부하가 크다면 .NET의 Timer를 쓰는 것이 적합함을 알아내었다. 본 연구를 통하여 개발자는 유니티에서 제공되는 주기성 제공 방법들 중에서 적절한 방법을 선택할 수 있다.