KINAC is trying to build a comprehensive aerial view of the nuclear material balance to predict North Korea’s weapons-grade nuclear material production capacity. We are creating a visualization model for North Korea’s nuclear facilities as part of these efforts. However, information on North Korea’s nuclear facilities is scarce, and it is not easy to consider additional facilities other than those already known. In addition, in the case of a model that targets only exceptional situations, it is not easy to secure objectivity for model validation, so it is necessary to upgrade to a general-purpose analysis tool that can be applied more generally. The following two examples are proposed as an analysis tool that can be a high degree of analysis. The first case is an Acquisition Path Analysis (APA) utilized to introduce IAEA’s State-Level Approach (SLA). The acquisition path analysis aims to find and evaluate the technically possible pathways to obtain nuclear materials for nuclear weapons or other nuclear explosive development. It can be an acquisition route if it is possible to produce at least 1 Significant Quantity (SQ) of weapongrade nuclear material within five years. The assessment of technologically feasible pathways is based on available information about the country’s past and present nuclear cycle capabilities. The second is the IAEA Physical Model. The IAEA Physical Model was carried out to introduce a comprehensive approach to all information on a country’s nuclear activities. It describes and characterizes the technologies and processes expressed at all levels of the acquisition path, depending on the development objectives. The IAEA Physical Model attempts a multi-tiered acquisition path analysis to identify all known technologies and processes in the nuclear fuel cycle, from raw material production to weapon usable material acquisition. Based on this analysis, the IAEA evaluates the signs of nuclear proliferation in a specific country. Based on the two cases discussed above, we intend to derive the following implications and priorities for extending the existing nuclear cycle model to a more general-purpose for a specific country. First of all, the requirements necessary to evaluate nuclear non-proliferation or verification of denuclearization must be at a level that the international community can recognize. In the stage of actual denuclearization verification, since verification will be conducted through the IAEA, a corresponding level of tools and technology will be required. From this point of view, the following is presented as a prerequisite for adding versatility to the existing physical model: It is necessary to derive all processes related to the nuclear cycle and standardize relevant indicators and data. In order to determine the signs of nuclear activity, detailed information on technologies, materials, by-products, and wastes, which are essential for each process, is required. For denuclearization verification, cumulative information from the past to the time point is required, and a comparative analysis of the operation history information of all facilities and the amount of nuclear material is required. To this end, it is necessary to make it possible to trace the history at every point where it can be determined that nuclear material has been diverted so that missing nuclear material can be found. Based on this, it is expected that it can be possible to evaluate a hypothetical threat state, but it is also expected that it will be easy to verify the model through the evaluation of easily accessible domestic facilities.
The study proposed a dual-path model to examine the relationship between customer perceived hotel innovativeness and customers’ interactivity, building the signaling theory. The model was tested with hotel customers from China. The findings suggest that customers’ perceived hotel innovativeness not only has a positive and direct impact on their interactivity, it also indirectly contributes to customers’ interactivity via two indirect paths, one featuring a cognitive-economic motivation pathway and the other featuring an affective-motivation pathway.
The stochastic point-source model has been widely used in generating artificial ground motions, which can be used to develop a ground motion prediction equation and to evaluate the seismic risk of structures. This model mainly consists of three different functions representing source, path, and site effects. The path effect is used to emulate decay in ground motion in accordance with distance from the source. In the stochastic point-source model, the path attenuation effect is taken into account by using the geometrical attenuation effect and the inelastic attenuation effect. The aim of this study is to develop accurate equations of ground motion attenuation in the Korean peninsula. In this study, attenuation was estimated and validated by using a stochastic point source model and observed ground motion recordings for the Korean peninsula.
The shortest path problem is one of network optimization problems. This paper considers a shortest path problem under the situation where lengths of arcs in a network include both uncertainty and randomness, and focuses on the case that the lengths of arcs are expressed by uncertain random variables. This paper presents a new type of model: relative entropy model of shortest path. By the definition of relative entropy of the uncertain random variables, relative entropy model of shortest path problem is proposed to find the shortest path which fully reflects uncertain and random information. This model is formulated to find a shortest path whose chance distribution minimizes the difference from the ideal one. A numerical example is given to illustrate the model’s effectiveness.
This study was to determine some appropriate models which account for attitudes toward practice of consuming dog (ACD) as a food and as a companion animal. Two models, one for males and the other females, were found from 670 community-dwelling respondents of the Gwangju Metropolitan area who aged 17~66 years. Age, keeping dog or willing to keep dog, and frequency of consuming dog as a food (FD) were exogenous variables in the models while attitudes toward companion animal were a mediating variable. The two models were slightly different, but the most influential variable accounting for the ACD was the FD. The findings of this study on the ACD were discussed in two dimensions of affect and utility which were motivational attitudes to animal. People who are against consuming dog meat as food would think of all dogs as only affectionate objects, and their points of view were discussed in the context of both keeping dog and restricting dog meat consumption. On the other hand, people who are for consuming dog meat would think of dogs as either affectionate or utilized objects, and their points of view were discussed in the context of halving dogs into companion dog and edible dog.
The psychosocial stress and musculoskeletal disorders(MSDs) have been one of major health problems for hospital workers. This study tried to understand the relationship between symptoms associated with MSDs and risk factors such as working posture, job stress, psychosocial stress and fatigue. A total number of 655 hospital workers participated in this study. Specifically, REBA was applied for evaluating working posture and a checklist prepared by KOSHA(Korean Occupational Safety and Health Agency) was used for symptom survey. A questionnaire from KOSHA was also used for collecting data associated with job stress, psychosocial stress and fatigue. All these data were formulated and modeled by path analysis which was one of major statistical tools in this study. Specifically, path analysis for the data we collected came up with several major findings. As a result, as for body part(neck), (waist) and (arms) the degree of risk of work posture measured with the use of job stress(KOSS), psycho-social stress(PWI-SF) and REBA is significantly more affected by fatigue than muscular skeletal disease related consciousness symptom. However, regarding bod(wrist), the degree of risk of work posture measured with the use of job stress(KOSS) and REBA is directly affected by muscular skeletal disease related consciousness symptom. This study is meaningful in that the study clarified the causal relations of the degree of risk of work posture, degree of fatigue, and muscular skeletal disease related consciousness symptoms by each body part measured with the use of work stress(KOSS), psycho-social stress(PWI-SF) and REBA.
A differential drive wheeled robot is a kind of mobile robot suitable for indoor navigation. Model predictive control is an optimal control technique with various advantages and can achieve excellent performance. One of the main advantages of model predictive control is that it can easily handle constraints. Therefore, it deals with realistic constraints of the mobile robot and achieves admirable performance for trajectory tracking. In addition, the intention of the robot can be properly realized by adjusting the weight of the cost function component. This control technique is applied to the local planner of the navigation component so that the mobile robot can operate in real environment. Using the Robot Operating System (ROS), which has transcendent advantages in robot development, we have ensured that the algorithm works in the simulation and real experiment.
선원의 행동은 해양사고에 있어서 주요한 원인이다. 본 연구에서는 은닉 마르코프 모델(Hidden Markov Model)에 기반하여 선원의 행동을 모델링하였다. 그런 후, 모델에서 추정한 행동의 경로분석을 통하여 어떠한 상황과 절차 그리고 오류에 의해서 해양사고가 발생되는지를 해석하였다. 모델 구현을 위하여, 선원의 행동을 해양안전심판원에서 간행된 재결 요약서에서 관측하였고, 관측한 결과는 SRKBB(Skill-, Rule-, and Knowledge-Based Behavior)를 기반으로 한 행동분류 프레임워크를 이용하여 HMM 학습에 적합한 행동 데이터 로 변환하였다. 선박유형별 선원의 행동을 모델링한 결과, 선박 유형별로 차별성이 있음을 확인하였고, 선원이 우선적으로 행한 행동경로의 식별이 가능하였다. 연구 결과, 본 연구에서 제안한 모델링 기법은 선원의 행동경로 예측에 적용 가능할 뿐만 아니라 해양사고 예방에 필요한 선원 행동 보정을 위한 우선순위 결정에 기여할 수 있을 것으로 기대된다.
In this study, an operational data set was analysed by establishing a path model to figure out the actual cause-effect relationship of a wastewater treatment plant (WWTP); in particular, for the effluent concentrations of T-N and T-P. To develop the path models, data sets of operational records including effluent concentrations and operational factors were obtained from a field scale WWTP of 680,000 m3 of treatment capacity. The models showed that the relationship networks with the correlation coefficients between variables for objective expressions indicated the strength of each relationship. The suggested path models were verified according to whether the analyzation results matched known theories well, but sophisticated minute theoric relationships could not be cropped out distinctly. This indicates that only a few paths with strong theoric casual relationships were represented as measured data due to the high non-linearity of the mechanism of the removal process in a biological wastewater treatment.
As a result of dividing typhoon that affected Korean Peninsular between 1999 and 2012 into 7 types of path and entering forecast field and analysis field of RDAPS, until 36 hours from the time of forecast, it is reliable to use the forecast field of RDAPS to predict typhoon and for each typhoon path, the difference between the forecast and the analysis shows normal distribution, which is usable for weather forecast until the 36th hour. In the 48th hour from the time of forecast, the difference of result depending on each typhoon path increased, which was analyzed to be due to errors in the forecast. It was expected that relatively reasonable results should be shown if the 36th hour forecast is used to predict the strength and distribution of strong wind. As a result of using Korean RAM and observing the difference of the maximum damage, reliability was secured up to 36 hours and after 48hours, it was expected that the fluctuation of results may become more severe.
The paper explores determinants of corporate adoption of social media and the role of technology acceptance model in the path. This paper assimilates some components of the technology acceptance dimension and social expectation theories to determine corporate intentions to use social media. Six hundred and forty-eight samples collected from hotel staff in Korea are analyzed using factor analysis, structural equation model techniques and one-way analysis of variance. The results show that corporate needs, social expectations, ease of use and usefulness should be viewed as important antecedents explaining the firm’s behavioral intention to use social media. The study also finds that the ease of use and usefulness of the technology acceptance model have positive directional mediation effects in the path diagram.
이 연구에서는 초․중등교사들의 TPACK 함양을 위한 전략을 마련하기 위하여 TPACK에 대한 교사들의 인지경로를 분석하고, TPACK 요소들 간의 구조적 관계를 밝혔다. 이를 위해 TPACK에 대한 교사들의 자기효능감을 측정할 수 있도록 기존의 측정도구를 번안하고, 평가관련 문항을 새롭게 추가하여 초 중등교사들을 대상으로 설문 조사를 실시하였다. 그런 다음, 설문 조사 결과를 바탕으로 탐색적 요인분석을 실시하였다. 분석 결과, 기존의 7개 요인 41개의 문항이 7개 요인 36개의 문항으로 재구성될 수 있었고, 확인적 요인분석을 통해 탐색된 TPACK 모델의 신뢰도와 수렴타당도, 판별타당도 등을 확보할 수 있었다. 또한 연구 가설에 기반하여 구조방정식모델을 구성할 수 있었는데, 이 모델을 통해 TPACK을 구성하는 요인들간의 인과 관계를 확인할 수 있었다. 예를 들어, 초 중등교사들의 경우, PK와 CK는 PCK에, TK와 PK는 TPK에, TK와 CK는 TCK에, PK, TPK, TCK는 TPACK에 각각 유의한 영향을 미치는 것으로 나타났으며, TK, CK, PCK는 TPACK에 유의한 영향을 미치지 않는 것으로 나타났다. 이와 같은 연구 결과는 교사들의 TPACK 함양을 위한 교사연수 프로그램이나 전략을 마련하기 위한 기초 정보를 제공해 줄 수 있을 것으로 기대된다.
흙의 응력-변형 관계는 흙의 종류, 밀도, 응력수준 및 응력경로에 의존한다. 이들 요소들을 통합한 구성모델의 개발을 통해 정확한 흙의 응력-변형관계가 예측되고 있다. 본 연구에서는 백마강 모래를 이용하여 등방압축-팽창실험과 일련의 응력경로를 달리한 배수삼축압축시험을 통하여 응력경로에 따른 Lade의 단일항복면 구성모델의 토질매개변수 특성에 대하여 알아보았다. 그 결과 항복기준에 관련된 토질매개변수 h, α는 응력수준 및 응력경로에 대한 영향이 미소하며, 응력-변형거동에 미치는 영향이 작은 것을 확인할 수 있었다. 그리고 항복함수에 관련된 토질매개변수 h와 α는 파괴규준에 관련한 토질매개변수와 관련성이 매우 높아 η1에 관한 식으로 대체할 수 있으며, 이 식을 이용한 수치해석 결과 양호하게 예측하고 있는 것을 확인 할 수 있었다.