Background: Because of the lack of accurate values for applied forces in manual therapy, manual therapists relies on the magnitude of the individual’s perception during applying the force. However, excessive loading maneuvers carry risks for patients. Objective: To establish the relationship between the maximal force applied to swine skin with the specific region, sex, and baseline parameters of the subject. Design: Ex-vivo Study and laboratory Experimental research Methods: 3.5 kg of Korean pork sirloin that is a piece of swine was handled and it was set 3 dimensions; #A; #B; #C. Forty-seven participants who has no experience in physical therapy randomly carried out the experiment, indicated to push each place of the pressure spots with same posture and process under supervision from the instructor who has over 15 years of manual therapy, and we measured the pressure force in each time. Results: The biggest pressure force was recorded in spot #A, and #B was represented after #C. Pressure on #A showed certain statistic relation with height (r=.317, p<.05) and weight (r=.434, p<.01); pressure on #B showed certain relation which has statistical meaning with only height (r=.401, p<.01); pressure on #C emerged to have statistic relationship with height (r=.308, p< .05)and weight (r=.428, p<.01). The age aspect revealed relation with pressure on #A, #B and #C, but that was not statistically significant. Conclusions: It can be inferred that there is the most loss of pressure in the area where cartilage is like an island in the middle.

목적 : 본 연구에서는 각기 다른 조명에서 조절반응과 동공의 크기 측정을 동적으로 하고 그에 따른 조절과 동공의 동적 변화가 시기능에 어떠한 영향을 미치는지 알아보고자 하였다. 방법 : 연구대상은 안과적 수술 경력이 없는 17명(23.06±0.51세)을 대상으로 하였고 기본검사를 통해 나안시력이 0.8 이상인 인원을 대상자로 선정하였다. 3개의 조명 조건(명소시, 박명시, 암소시)에서 개방형 자동굴절검 사기(WAM-5500)를 통해 5 Hz로 조절 및 동공크기를 동적으로 측정하였으며 조절자극은 40 cm, 40~30 cm, 30 cm, 30∼20 cm, 20 cm에서 5초간 주었다. 더불어 원거리 시력 및 대비감도를 측정하였다. 결과 : 명소시 상태에서 조절반응량이 가장 높았으며 암소시 상태에서 조절반응량이 가장 낮게 나타났다(p ＜0.050). 동공의 크기 변화는 명소시 상태에서 동공의 크기가 가장 작게 측정되었고, 암소시 상태에서 동공 크기가 가장 크게 측정되었다(p＜0.050). 시력과 대비감도에서도 명소시 상태에서 모두 가장 높은 수치를 나타냈으며, 암소시 상태에서 시력과 대비감도 모두 가장 낮게 측정되었다(p＜0.050). 결론 : 본 연구의 결과로 다른 조명 조건하에서 조절자극이 변화될 때 조절반응량과 동공크기가 연속적으로 변화됨을 알 수 있었다. 낮은 조도에서 조절반응량은 조절자극보다 낮게 나타났고 시력 및 대비감도 모두 저하되었다. 이것은 정적인 상태에서도 조절의 지속적인 변화를 나타낸다. 그러므로 조절 또는 시기능 검사 시 동적 측정이 필요할 것으로 사료된다.

The Dynamic Vehicle Routing Problem (DVRP) involves a combinatorial optimization problem where new customer demands become known over time, and old routes must be reconfigured to generate new routes while executing the current solution. We consider the high level of dynamism problem. An application of highly dynamic DVRP is the ambulance service where a patient contacts the service center, followed by an evaluation of case severity, and a visit by a practitioner/ ambulance is scheduled accordingly. This paper considers a variant of the DVRP and proposes a decentralized algorithm in which collaborators (Depot and Vehicle), both have only partial information about the entire system. The DVRP is modeled as a periodic re optimization of VRP using the proposed decentralized algorithm where collaborators exchange local information to achieve the best global objective for the current state of the system. We assume the existence of a dispatcher e.g., headquarter of the company who can communicate to vehicles in order to gather information and assigns the new visits to them. The effectiveness of the proposed decentralized coordination algorithm is further evaluated using benchmark data given in literature. The results show that the proposed method performed better than the compared algorithms which utilize the centralized coordination in 12 out of 21 benchmark problems.

본 논문에서는 폭발하중을 받는 철근콘크리트 슬래브의 비선형 해석을 위한 개선된 수치 모델을 제안한다. 제안된 모델은 2축 응력 상태를 반영한 등가 강도에 의해 정의된 응력-변형률 관계를 사용하여 응력 상태를 직접 결정하는 변형률 속도 의존 이등방성 구성 모델을 다룬다. 또한, 균열 발생 후 콘크리트와 철근 사이의 부착 슬립이 점차 확대되어 소성힌지 영역으로 집중된다. 2축 응력 상태에서 콘크리트의 균열 방향은 주응력 방향에 따라 달라지므로 이를 고려한 부착 슬립 모델을 해석에 도입하였다. 해석 모델의 검증을 위해 수치해석과 실험결과의 상관관계 연구(correlation studies)가 수행되었다. 해석 결과는 재료모델의 2축 거동과 부착 슬립의 영향을 고려하는 것이 해석결과의 정확성 향상에 중요함을 보여주며 제안된 해석 모델이 철근콘크리트 슬래브 부재의 폭발해석에 효과적으로 사용될 수 있음을 확인하였다.

PURPOSES : For compaction control on the subgrade layer, the simple and economical test DCPT (Dynamic Cone Penetrometer Test) is being applied to the Korea Pavement Design Guide. However, compaction control is now difficult and to conduct in the field and is not performed in practice because the compaction degree is evaluated via the field density test as a pretreatment step when the compaction management process is evaluated by DCPT at the same time. Therefore, this study tried to propose a method considering an evaluation for the compaction degree using DCPT, via laboratory tests and field tests. METHODS: The in-situ DCPT tests were conducted according to the types of subgrade soils in the field. Afterward, the field density tests for the compaction degree (R) of field samples and the experiments using DCPT were performed simultaneously in a self-made test container in the lab. RESULTS: Through the DCPT test, compaction degree evaluation from the correlations proposed in this study was determined to be possible. Additional field tests could verify the proposed correlations between compaction degree with DCPT PR on the subgrade. CONCLUSIONS: For the evaluation of the subgrade compaction degree using dynamic CPT, the correlations between compaction degree and DCPT PR on the subgrade layer are proposed from laboratory tests and field tests using DCPT and field density tests.

Recently, the occurrence frequency of earthquake has increased in Korea, and many cultural assets have been damaged. Cheomseongdae is a valuable cultural assets that must be preserved historically and culturally. But, the masonry structure such as Chemseongdae is vulnerable to lateral forces. Therefore, in this study, structural modeling and dynamic analysis are performed to reflect the ground state and structural form of Cheomseongdae. Also, discrete element analysis technique is applied and dynamic behavior characteristics are analyzed according to earthquake load. For this purpose, displacements and stresses according to locations are reviewed and then swelling and distortion are analyzed.

급속한 경제발전은 많은 국가에게 여러 가지 시사점을 주고 있다. 특히, 경제발 전 초기에 KIST설립을 통해 산업발전의 초석을 쌓은 일은 한국 산업발전의 성공요인 중 하나라고 알려져 있다. 그동안 KIST사례에 대한 여러 연구가 있었지만 기술경영 관점에서 KIST의 성공요인을 이론적인 분석틀 안에서 체계적으로 사례연구를 진행한 사례는 많지 않다. 본 연구에서는 역동적 역량과 혁신시스템 이론을 기반으로 KIST사례에 대한 정책적 요인을 분석해보고자 한다. 특히, 산업정책, 과학기술정책, 인력정책을 토대로 KIST의 기술적 역량과 혁신시스템 내 조직적 역량을 통해 산업발전을 이룬 성공요인에 대해 심층적인 사례 분석을 실시하도록 한다. 본 연구를 통해 개발도상국의 과학기술정책과 산업발전에 대해 정책적 시사점을 줄 수 있을 것으로 기대된다.

The world of smart agribusiness is still far from being fully and effectively applied by the Italian entrepreneurial fabric. In part, this is due to the fact that its potential and important connections with the technological world of reference are not fully known. The imperative is therefore: to learn how to manage all the processes that characterize the agricultural chain in a synergistic way, from production to the sale of the product to the final consumer. It is therefore essential to know every minimum aspect of the supply chain considering the current strengths on which to leverage but especially the weaknesses on which to intervene thanks to the use of technology available on the market. Today, the supply chain is still considered as a set of phases, one consecutive to the other, as if they were detached from each other. However, in order to operate efficiently, each step should be interconnected: from the farmer’s decision to produce an agricultural good to the choice of production factors, from the implementation of harvesting and post-harvest operations to processing, from the selection of goods suitable for sale to the logic of distribution on the target territory. This work investigates the potential strategy using digital technologies in order to make dynamic the agribusiness supply chain, especially because in Italy the agri-food is one of the most important economic sectors but it is far from the most innovative trends available on the market.

Background: Cervical dysfunction is a common pathomechanical marker in individuals with forward head posture (FHP). To overcome the limitations of the isometric chin-tuck (ICT) exercise, dynamic neuromuscular stabilization (DNS), which emphasizes an entire spinal chain exercise, has recently shown promising clinical results. Objects: Purpose of this study was to compare the immediate effects between ICT and DNS techniques. Methods: 43 young subjects (mean age, 24.0±5.0 years) were recruited. Group of subjects with FHP were measured under baseline, ICT, and DNS conditions. Outcome measures included sitting height, longus colli (LC) and sternocleidomastoid (SCM) muscle thickness and LC/SCM thickness ratio. One-way repeated measures ANOVA was used to compare the continuous dependent variables among FHP, ICT, and DNS conditions at p<.016. Results: Both ICT and DNS exercise conditions yielded significantly increased LC muscle thickness, LC/SCM thickness ratio and sitting height than did FHP condition (p<.0001, respectively). Sitting height was significantly greater in DNS exercise than in the ICT exercise (p<.0001). Conclusion: The present results demonstrated that sitting height was greater in the DNS exercise than in the ICT exercise, as well as both corrective postural training exercises were effective on LC/SCM muscle balance ratio when compared with the baseline FHP condition. Therefore, it is considered that DNS exercise can be the recommended exercise for people with FHP.

Background: Lumbar lordosis is a result of muscle shortening and may cause low back pain. Objective: To examine the effects of static and dynamic stretching on lumbar lordosis and low back pain in university students. Stretching is an intervention that can be applied to shortened muscles; however, very few studies have compared the effects of static and dynamic stretching on lumbar lordosis and low back pain. Design: Randomized controlled clinical trial (single-blind) Methods: The 12 selected subjects were randomly assigned static stretching and dynamic stretching groups each containing six students. The subjects in each group performed their respective stretching programs for 17 minutes, 3 times a week for 4 weeks. Lumbar lordotic angle, low back pain, and Oswestry Disability Index (ODI) were measured before and after the intervention. Results: Intragroup comparisons showed significant reductions in lumbar lordotic angle and low back pain in the static stretching group while the dynamic stretching group showed significant decreases in lumbar lordotic angle, low back pain, and ODI. The intergroup comparisons showed significantly greater differences between pre- and post-intervention in lumbar lordotic angle and low back pain in the dynamic stretching group compared to those in the static stretching group while ODI did not show any intergroup difference. Conclusions: The results of this study indicated that, while both static and dynamic stretching helped to reduce the lumbar lordotic angle and low back pain, dynamic stretching was more effective in alleviating lumbar lordotic angle and low back pain compared to static stretching.

스카이브릿지로 연결된 쌍둥이 초고층건물은 두 가지 종류의 연동성-스카이브릿지로 인해 두 건물의 거동 동기화를 유발하는 구조적 연동성과 작용하는 풍하중의 높은 상관성으로 인한 공기역학적 연동성-이 나타난다. 단일 건물에 널리 적용되는 전통적인 풍력실험 방법으로는 이런 연동성과 영향들을 완벽히 파악할 수 없는 실정이다. 그런 이유로 보다 발전된 동적 풍응답 해석법이 요구된다. 이 논문은 스카이브릿지로 연결된 쌍둥이 건물에서 발생하는 구조적 및 공기역학적인 연동성을 다룰 수 있는 듀얼 풍력실험 방법을 자세히 다루었다. 제안된 방법을 적용하여 건물의 풍가속도에 대한 구조적 및 공기역학적 연동성의 영향을 평가하였다. 건물의 풍응답 산정에 스펙트럼 적분법과 백색 소음 근사법을 적용하였다. 실험 및 결과로 볼 때 동적 풍응답에 상당한 영향이 있음을 확인할 수 있었다. 여러 개의 풍력 측정센서를 활용한 풍력실험 기술은 구조적으로 연결된 초고층건물에 대한 풍동실험에 유용하게 사용될 것으로 판단된다.

목적：간 역동적 검사 시 호흡이 불규칙하거나 호기 후 정지의 어려움을 갖는 환자의 경우 영상의 질이 저하된다. 이 문제점을 해결하기 위해서 GRAPPA, CAIPIRHINA, Compressed Sensing 기법을 사용하여 호흡 정지 시간을 단축하고 있다. 본 연구에서는 acceleration factor 8, 9, 10을 적용한 CS 기법과 초기 동맥기와 동맥기를 동시에 얻을 수 있는 Double arterial phase 기법을 사용하여 VIBE 영상을 얻어 비교함으로써 최적 acceleration factor 값과 phase를 평가해보고자 한다. 대상 및 방법：2019년 8월 19일부터 9월 20일까지 본원에서 간 MRI 검사를 시행한 환자 15명을 대상(남자 10명 여자 5명 64±12.6세)으로 단일 호흡 정지 동안 2번 측정되는 double phase image를 사용할 때, acceleration factor를 각각 8, 9, 10으로 변화를 주고 다른 변수들은 같게 하여 실험을 진행하였다. 획득한 acceleration factor 값과 phase가 다른 각 영상의 SNR, CNR을 측정하여 정량적 평가를 진행하고, 정성적 영상평가와 호흡 정지 시간의 변화를 비교하였다. 결과：같은 phase에서 acceleration factor의 값이 9, 10, 8 순으로 SNR이 높았으며, acceleration factor가 8, 10일 경우 SNR이 phase 1보다 phase 2가 높았고, acceleration factor가 9일 경우에는 phase 1가 더 높았다. phase 1의 CNR은 acceleration factor 9, 8, 10 순으로 높았고, phase 2에서의 CNR은 acceleration factor 9, 10, 8 순으로 높았다. acceleration factor가 8, 9인 경우는 phase 1의 CNR이 높았고, 10인 경우 phase 2의 CNR이 높았다. 결론：본 연구의 실험결과를 종합하였을 때 acceleration factor 9를 적용한 double phase image 중 Phase 1에서 가장 높은 SNR과 CNR을 확인할 수 있었다. 또한, 호흡 정지시간 역시 acceleration factor 8 대비 acceleration factor 9에서는 13% 감소하고, acceleration factor 10에서는 20% 감소한 효과를 얻었다. CS 기법을 사용한 간의 역동적 Double Phase 검사 시 영상의 질의 변화에 큰 유의함이 없는 상태로 acceleration factor를 조절하여 호흡 정지시간을 줄이고, 2개의 영상 중 선택하여 임상적으로 활용할 수 있다고 생각한다.

In this research, a simulation program is developed in order to investigate non steady-state cornering performance of 6WD/6WS special-purpose vehicles. 6WD vehicles are believed to have good performance on off-the-road maneuvering and to have fail-safe capabilities. But the cornering performances of 6WS vehicles are not well understood in the related literature. In this study, 6WD/6WS vehicles are modeled as a 18 DOF system which includes non-linear vehicle dynamics, tire models, and kinematic effects. Then the vehicle model is constructed into a simulation program using the MATLAB/SIMULINK so that input/output and vehicle parameters can be changed easily with the modulated approach. Cornering performance of the 6WS vehicle is analyzed for brake steering and pivoting, respectively. Simulation results show that cornering performance depends on the middle-wheel steering as well as front/rear wheel steering. In addition, a new 6WS control law is proposed in order to minimize the sideslip angle. Lane change simulation results demonstrate the advantage of 6WS vehicles with the proposed control law.