Earticle

게임 엔진과 같은 3D공간에서 프로시저럴 모델링 애셋을 사용하여 도시를 구성하는 방식은 이전부터 존재하여 다양한 방법으로 제작되어 왔습니다. 초기 제작시간은 길지만 라이브러리가 구축됨에 따라, 크기와 모양이 다양한 건물을 보다 빠르고 다양하게 배치가 가능하다는 장점 을 바탕으로 사용되었습니다. 하지만, 앙곡과 안허리곡으로 이루어진 이중곡선을 가지며 결구 방식에 따라 모양이 변화하는 한옥의 경우에는 프로시저럴 기법으로 모델링 애셋을 제작하기 어려워 수동 모델링이나 스캔 데이터 형식으로만 존재하는 불편함이 존재하였습니다. 그렇기 에, 본 연구에서는 게임 엔진에서 사용이 가능한 가변적인 한옥 모델링에 대한 프로시저럴 기 법에 대해 소개하고자 합니다.

The method of constructing a city using a procedural modeling asset in a 3D space such as a game engine has existed since before and has been produced in various ways. Although the initial production time was long, it was used based on the advantage that buildings of various sizes and shapes could be arranged faster and more variously as the library was built. However, in the case of Han-ok, which has a two dimensional curve and whose shape changes depending on the articulation method, it was difficult to produce a modeling asset using a procedural technique, so there was an inconvenience that existed only in the form of manual modeling or scan data. Therefore, in this study, we would like to introduce a procedural technique for variable Han-ok modeling that can be used in game engines.

본 연구는 3D 프린팅의 확산과 함께 일반화되고 있는 디지털 기반 디자인의 특성을 조형적 측면에서 통해 분석해 보고자 하였으며, 그 대상은 현재 패션디자인 분야 중 3D 프린팅이 가장 적극적으로 수용되고 있는 패션 액세서리 분야로 한정하였다. 전통적 패션 액세서리 디자인과 차별화된 조형 요소 중 디지털 디자인 기법을 통해 만들어지는 확장적이며 비정형적인 형태를 중심으로 디자인 사례를 분석하였다. 형태의 생성 원리와 툴의 특성이 다른 디지털 디자인의 기법을, 현재 가장 많이 사용되는 프랙탈(Fractal), 넙스(NURBS), 파라메트릭(Parametric) 기법으로 유형화하고 이를 기반으로 3D 프린팅 패션 액세서리 디자인 사례들의 형태, 면, 공간 특성을 분석하였다. 연구 결과, 프랙탈 기법에 기반한 3D 프린팅 패션 액세서리 디자인은 유닛의 독창성과 중첩, 연결 방식에 따른 형태의 비정형성이 특징적이었고, 넙스 기법에 기반한 3D 프린팅 패션 액세서리 디자인의 경우 선과 각도에 의한 유기적 곡면과 공간의 교차를 통해 만들어지는 비정형적 형태와 공간을 특징으로 하고 있었다. 파라메트릭의 경우 유닛의 가변적 확장성 및 비정형적 형태와 공간이 표피 형태와 결합되면서 만들어지는 비정형적 조형 특성을 나타냈다. 종합해 보면, 디지털 디자인 기법에 따른 3D 프린팅 패션 액세서리 디자인의 비정형적 조형 특성은 가변적이며 확장적인 형태, 유기적이며 상호관입적 공간, 표피 형태에 의해 확장되는 비정형적 형태로 특징지을 수 있었다. 본 연구의 결과는 디지털 디자인 기법에 따른 비정형적 조형 특성에 대한 기반 연구로 의미가 있으며, 디지털 기반 패션디자인의 조형적 특성을 이해하고 조형 활동에 활용할 수 있는 실용적 의미가 있다. 본 연구의 대상은 패션 액세서리 분야로 한정되었으나, 디지털 패션에 대한 포괄적 이해를 위해 추후 연구에서는 디지털 프린팅을 활용한 패션디자인으로 확장될 수 있을 것이다.

This study aimed to analyze the formative characteristics of digital design regarding the spread of 3D printing technology. The scope of this study was limited to fashion accessories based on 3D printing technology. This study focused on the scalable and atypical forms which are discriminatory to the traditional fashion accessories. The generating principle of atypical forms and the methods of digital design were used to assess the characteristics of 3D printing fashion accessories. The general methods of digital design for 3D printing were grouped as Fractal, NURBS modeling, Parametric design. As a result, 3D printed fashion accessories based on Fractal method were characterized by the abnormal formation of the uniqueness of unit and the connection of the units. In the case of 3D printed fashion accessories based on NURBS modeling, atypical forms and space created by the intersection of the organically curved lines and space were the main factors for the atypical forms. In the case of Parametric design, the variable scalability, atypical forms and spaces of the units were the important atypical characteristics that made atypical forms combined with the skin type. In conclusion, the atypical characteristics of 3D printing fashion accessory designs were summarized as follows; the variable and expandable forms, the organic and interpenetrating spaces, atypical forms extended by skin shapes. This result could be used as an academic base to study atypical characteristics of digital design and suggest an adaptive direction of digital fashion design. For the further study, the range of digitalized fashion design could be extended to the digitally printed clothing.

the worldwide clothing fashion industry has played a crucial role in the small production of multiple grades, customer-oriented industrialization, cultural industrialization, high value added industrialization, and globalization. In addition, as there is growing demand for and interest in functional wear and smart design, the digital pearing as a new domain along with the application of computers to fashion in the fashion industry. Therefore, as a study on the utilization of pattern systems that have developed in such a digital environment, this study is about system utilization that allows us to forecast in advance erors that f completion before completion by confirming the status of fitting in a 3D simulation procedure through a 3D patern system.Therefore, the detailed objective of this study is to find characteristics of the 3D pattern system in the course of producing patterns and applying all procedures ofthe clasification of figures of Korean women in their 20s, and to identify any problems in utilization that might appear in the course of the operation. Also, the study proposes maters to be improved in utilizing the system before the substantial distribution of theand limitations found in the research procedure. The limitations identified in this study may be largely classified as follows. First, the problems may include the limitation in preparing a human body model. Second, there is a problem in the course of the wearing test in a virtual mock test, and the details may be sumarized as folows. First, the problems lie in the imperfectness of preparing diverse human body models according to

An davanced method for the automatic generation of parametric models in computer- aided design systems is required for most of two-dimensional model which is represented as a set of geometric elements, and constraining scheme formulas. The development system uses geometric constraints and support of topology parameters from feature recognition and grouping the design entities into optimal ones from pre-designed drawings. The aim of this paper is to present guidelines for the application and development of parametric design modules for the standard parts in mechanical system, the basic constitutional part of mold base, and other 2D features.

Free-form shapes which were once considered as an aesthetic feature are now an important functional requirement. CNC industries are looking for a compact solution for reproducing free-form shapes as conventional interpolation models are inadequate, The parametric curve interpolator developed in the last decade has clearly emerged as favorite among its contemporaries in recent years, At present intense research has been done on parametric curve interpolators and interesting developments are reported. Out of the various parametric representations for curves and surfaces, NURBS has been standardized and widely used in free-form shape design. This paper presents a review of various methods of parametric interpolation for NURBS and discusses the salient features, problems and solutions. Recent approaches on variable feedrate interpolation, parameter compensation are also reviewed and research trends are addressed finally.

In recent years, plastics have begun to show great commercial potential especially in manufacturing micro-structured parts. Injection molding and hot embossing are two major microfabrication methods. Replication accuracy was investigated for these two methods. Polymethyl methacrylate (PMMA) was used as the polymer substrate. The mold insert (or master) was fabricated by LIGA-type method. In this study, hot embossing was found to have better replication accuracy for microstructure than injection molding. Experiments were also conducted to study the effects of process parameters on the replication quality.

This paper deals with the geometric fitting algorithms for parametric curves and surfaces in 2-D/3-D space, which estimate the curve/surface parameters by minimizing the square sum of the shortest distances between the curve/surface and the given points. We identify three algorithmic approaches for solving the nonlinear problem of geometric fitting. As their general implementation we describe a new algorithm for geometric fitting of parametric curves and surfaces. The curve/surface parameters are estimated in terms of form, position, and rotation parameters. We test and evaluate the performances of the algorithms with fitting examples.

The growing demand for efficient and reliable propulsion systems in small and medium-sized vessels has revealed the limitations of conventional shaft-based systems, which often suffer from low transmission efficiency, high maintenance costs, and excessive noise and vibration. Even advanced pod-type propulsors frequently fail to meet the specific efficiency needs of small underwater vehicles operating in confined spaces. The hubless rim-driven thruster (RDT) presents a novel propulsion concept by integrating the ducted propeller and electric motor into a single, compact unit, eliminating the traditional bulky shaft and sealing components. This design enhances hydrodynamic efficiency and offers superior resistance to entanglement, making it an ideal solution for challenging marine environments. This study explores the parametric design and optimization of hubless RDT blades to enhance propulsive performance in shallow-water and small-scale underwater applications. Using STAR-CCM+ simulations, we systematically analyze the impact of paddle blade pitch angle and chord length on hydrodynamic performance. The resulting comprehensive dataset is utilized to train a machine learning surrogate model, facilitating rapid performance prediction and optimization. By employing an improved adaptive Sparrow Search Algorithm, we identify the optimal geometric parameters, achieving a 3-7% increase in propulsion efficiency while maintaining structural reliability under optimal operating conditions. The findings of this research provide a robust, data-driven methodology for designing the next generation of highly efficient and reliable propulsion systems for small underwater vehicles, contributing significantly to the field of marine engineering.

In this paper we define a two parametric new generalized useful average code-word length $L_{\alpha}^{\beta}$(P;U) and its relationship with two parametric new generalized useful information measure $H_{\alpha}^{\beta}$(P;U) has been discussed. The lower and upper bound of $L_{\alpha}^{\beta}$(P;U), in terms of $H_{\alpha}^{\beta}$(P;U) are derived for a discrete noiseless channel. The measures defined in this communication are not only new but some well known measures are the particular cases of our proposed measures that already exist in the literature of useful information theory. The noiseless coding theorems for discrete channel proved in this paper are verified by considering Huffman and Shannon-Fano coding schemes on taking empirical data. Also we study the monotonic behavior of $H_{\alpha}^{\beta}$(P;U) with respect to parameters ${\alpha}$ and ${\beta}$. The important properties of $H_{{\alpha}}^{{\beta}}$(P;U) have also been studied.

For large facilities having several floors or containers, floor response spectra, FRS, other than ground response spectra need to be developed. However, FRS can have error especially when components are not small in their masses. In this paper, error is estimated in order to specify applicability of the FRS by deriving and comparing with analytic results for two degrees of freedom system. An identity regarding modal vectors and participation factors in the modal method is used to measure the FRS error. It is found that FRS is sufficiently accurate if the mass of a component is one hundredth or less than that of the floor. On the contrary, it is shown that fixed frequency of a component does not affect the FRS accuracy considerably. A compact power plant system consists of two main assemblies with spring mounts is applied as an example for the derivation of the FRS and several aspects associated with its modeling and calculation are discussed.

Slider bearings are widely applied in mechanical systems, where the design needs cover increased load capacity, lowered friction and power consumption and creative designs. This work is governed to perform a parametric characterization, by generating a novel structure on the upper slider surface, which can formally be expressed in micro-machined wavy-form, where the individual and combined influences of various structural design parameters and boundary conditions, on the performance records, are also evaluated. Computations put forward that the contribution of the wave amplitude on power loss values is highly dependent on the level of inlet pressure; higher amplitudes are determined to increase power loss in the lowest inlet pressure case of 1.01, whereas the contrary outcome is determined in the higher inlet pressure cases of 3.01 & 5.01. Designing the slider bearing system, based on optimal load capacity, produced the optimum wave number ranges as 10-45, 7-11 and 5-8 for the pad inclinations of $5^{\circ},\;4^{\circ}$ and $3^{\circ}$ respectively.

The development of the high-efficiency machine-tools equipment and new cutting tool materials with high hardness, heat- and wear-resistance has opened the way to application of high-speed cutting process. The basic argument of using of high-speed cutting processes is the reduction of time and the respective increase of machining productivity. In this sense, the spindle units may be regarded as one of the most important units, directly affecting many parameters of high-speed machining efficiency. One of the possible types of spindle units for high-speed cutting is the air-bearing type. In this paper, we propose the mathematical model of the dynamic behavior of the air-bearing spindle. To provide the high-level of speed capacity and spindle rotation accuracy we need the adequate model of "spindle-bearings" system. This model should consider characteristics of the interactions between system components and environment. To find the working characteristics of spindle unit we should derive the equations of spindle axis movement under the affecting factors, and solve these equations together with equations which describe the behavior of lubricant layer in bearing (bearing stiffness equations). In this paper, the three influence coefficients are introduced, which describe the center of spindle mass displacement, angle of shaft rotation around the axes under the unit force application and that under the unit torque application. These coefficients are operated in the system of differential equations, which describes the spindle axis spatial movement. This system is solved by Runge-Kutta method. Obtained trajectories and amplitude-frequency characteristics were then compared to experimental ones. The analysis shows good agreement between theoretical and experimental results, which confirms that the proposed model of air-bearing spindle is correctis correct

With the rapid development of computer technology and ongoing destruction of traditional buildings, more and more attention is paid to digital methods for the design and preservation of traditional buildings. Unlike 2D methods, Building Information Modeling (BIM) provides an object-oriented and parametric digital representation way for traditional building components. However, one of the main limitations currently is that parametric information cannot be exchanged between BIM software packages. Therefore each kind of software must have their own parametric library which causes extensive works. In this research, the authors developed an open BIM-based library using an XML parametric approach to solve the above problems, represented traditional components according to an XML schema, and parametrically implemented these XML files in a browser which can be accessed by users for their easy component edit and selection. And then based on the XML file of one component, implemented an Add-on in ArchiCAD for users to parametrically edit and directly utilize. Thus based on these XML files, a browser for users' view and selection purpose and an add-on for users' application purpose were developed. Future research will focus on implementing these XML files in other BIM tools like Revit and Digital Project. If the whole library was to be completed based on this XML approach, an open BIM-based library would be established that all kinds of BIM software users could apply this parametric library for easy modeling of traditional houses.

In this paper, properties of hydrologic cycle in three experimental catchments were compared and different types of a lumped parametric model were applied to understand the hydrologic cycle in the catchments. One of them is a forest catchment and another one includes the reclained upland fields and last one does terraces paddy fields. The comparison of hydrologic properties showed that the differences in land used have great influences on the soil properties of surface layer, which cause changes in hydrologic processes such as evapotranspiration and storm runoff et.al. By the runoff analysis models, good agreements between observed and calculated discharge from the catchments were obtained and it was found that the differences in values of optimized model parameters and water budget components reflect those in the hydrologic cycle among them.

임베디드 시스템의 발전으로 인해 다양한 품질 속성에 대한 요구사항들이 증가하고 있다. 배터리를 사용하는 모바일 임베디드 시스템의 경우 제한된 전력공급으로 인해 시스템의 전력소모를 절감하기 위한 노력이 요구된다. 특 히 임베디드 시스템에 탑재되는 소프트웨어들이 점차 복잡해지고 다양한 기능을 수행함에 따라 소프트웨어에 대한 소모전력 절감 연구들이 관심 받고 있다. 또한 최근에는 모델 기반 소모전력 분석을 통해 소프트웨어 개발 초기 단계 에서 소모전력 요구사항을 반영하기 위한 연구들도 진행되고 있다. 따라서 본 논문에서는 SysML(Systems Modeling Language)의 Parametric 다이어그램을 이용한 모델 기반 소모전력 분석 기법을 제안한다. 제안하는 기법은 Parametric 다이어그램의 특성을 이용하여, 실제 전력소모를 유발하는 소프트웨어의 행위에 대한 모델을 작성한다. 이를 기반으로 소프트웨어의 실행으로 인한 소모전력 값을 도출할 수 있으며, 같은 기능을 갖는 모듈들에 대한 소모전 력 품질속성을 비교할 수 있다는 장점이 있다.

Various quality requirements have increased in developing embedded systems. One of those requirements in mobile embedded system is to reduce energy consumption because of limited power supply. Especially as the complexity of embedded software is increased, the interests of the software energy consumption analysis is also increased. In recent years, some studies has been carried out model-based analysis because it can be able to reflect energy consumption requirements in design phase. In this paper, we proposes a model-based energy analysis technique using SysML parametric diagram. The proposed technique designs software activity model using characteristics of parametric diagram, and then energy consumption value by the execution of the model is derived. Our technique has merit that can perform tradeoffs analysis for energy quality property between different implementations.

중력모형에 의존하여 경제효과를 설명할 경우, 지금까지 주로 패널데이터(panel data) 분석을 통한 개별 고정효과 패널 분석(individual fixed effect)을 수행하였다. 본 연구에서는 기존의 패 널 데이터의 고정효과 분석이 아니라 새로운 인공신경망(Artificial Neural Network)을 이용한 예측을 시도하였다. 특히, 그 중에서도 파라미터부분과 인공신경망의 비-파라미터 방식의 혼 합으로 이루어진 반-모수 패널 신경망(semi-parametric panel neural network)을 방법론으로 채택 하였다. 이 방법을 이용하여, 일본과 한국의 2개 국가에 대하여, 각각의 10년 예측과 5년 예측 의 두 종류의 기간에 대하여, 전통적 고정효과 패널 분석(panel individual fixed effect)과 함께 반-모수 패널 신경망(semi-parametric panel neural network) 분석을 시도하여 총 여덟 종류의 학 습과 예측을 실시하였다. 결과 반-모수패널 인공신경망이 여덟 개 케이스 중에서 일곱 개 케이 스에서 전통적 고정효과 패널 추정 방식보다 예측에서 우수한 결과를 보여 주었다.

Purpose : To compare the predictability of gravity model based on panel data, the two methodologies are used and compared. One comes from the traditional panel individual fixed effects and the alternative methodology comes from semi-parametric panel neural network. Research design, data, methodology : The exporting cases of Korea and Japan, for 30 years of data with 247 countries of export partners, were analyzed. Two scenarios dividing the learning period into 20 years with 10 years’ prediction period and the 25 year learning period with 5 years’ prediction periods are performed and compared. Results : The semi-parametric panel artificial neural network outperformed than the traditional panel fixed effect method in 7 out of 8 cases in terms of MSE. Conclusions : The results showed the superiority of semi-parametric neural networks in the analysis and forecasting based on panel data compared to traditional fixed effect panel analysis.

The main goal of this paper is to illustrate the explanatory power of parametric approaches on the verbal orders between V and T in Early Middle English such as ‘spoke not’, ‘not spoke’, ‘did not speak’ and ‘did speak’ and choose which approach might be not only described but explained in the optimal way in terms of the Minimalist program frameworks. In GB and early minimalism language variation can be accounted for by language specific and language-independent parametric approaches. Thus it is revealed through GB and Minimalism that a number of language specific parametric approaches such as Overt/Covert parameter(Chomsky 1993, 1995), AGR-1 parameter(Pollock 1989, Roberts 1993), Spell-out parameter (Groat and O‘Neil 1996), Strong/weak T-parameter(Chomsky 2014) and Category-Specified parameter(Kim 2019) are introduced to explain the verbal orders between V and T. However according to the central tenet of recent minimalism(after Chomsky 2005) these parameters coupled with UG(Universal Grammar) must be simple and no-redundant to reduce the size and options of UG. Therefore specific parametric approaches should be driven to be decomposable into a unified one which can account for every aspects of verbal orders between T and V. In this presentation I will discuss how each parametric approach can deal with the Early Middle English verbal orders in conformity with the tenet of Minimalism and it is concluded that Category-Specified parametric approach in which T and V of UG are under-specified to Category is shown to be the best one to deal with the Early Middle English verbal orders, allowing grammar to account for language variation without appeal to language specific parameters of UG.

본 저자들은 다품목 위험기피 뉴스벤더 모형에 대한 매개분석을 실시하였으며, 위 험 측도로는 최근에 들어 재무관리 뿐 아니라 재고관리 문헌에서 활발하게 사용되고 있는 조건부 밸류 앳 리스크 (conditional value-at-risk)가 이용되었다. 본 모형에서 첫째로 다품목 하에서 모형의 모수들에 대한 비교정태분석 (comparative static analysis)을 실시하였다. 특히 품목들이 완전히 동일함과 동시에 품목 수요가 독립적 이고 대칭적일 때 리스크 허용 요인 (risk tolerance factor)이 증가함에 따라 품목 별 최적 주문량이 단조증가됨을 증명하였다. 또한 이같은 최적해들은 품목 수가 무한히 증가함에 따라 근사적으로 위험 중립해에 근사함을 증명하였다. 최종적으로 몬테카를 로 (Monte Carlo) 시뮬레이션을 실시하여 수리적 해 (numerical solutions)들을 구함 으로써 모든 분석적 결과들을 확증하였다.

We consider a multi-product risk-averse newsvendor with a parametric analysis approach. For this risk-averse decision maker with multiple products, we use a well-known risk measure, CVaR (Conditional Value-at-Risk), which has been recently used in inventory management as well as finance literature. We first study our comparative static analysis for the model parameters in a multi-item setting. Especially, under the identical product assumption with independent and symmetric product demands, we prove that the optimal ordering quantity monotonously increases when the risk tolerance factor increases. We also prove that the optimal ordering quantity asymptotically converges to the corresponding risk-neutral solution as the number of products goes to infinity. Finally, we conduct a Monte Carlo simulation to obtain numerical solutions. All our analytical results are confirmed in the numerical study.

The damping effects on stabilities of a simply supported pipe conveying fluid is investigated using the complexification-averaging method. The flow is assumed to vary harmonically about a mean speed. Unstable conditions of a piping system included with the viscous and material damping are analytically obtained for primary, secondary and combination parametric resonances. The primary and secondary resonances occur when the frequency of flow fluctuation is close to one and two times the natural frequency. And when this frequency is close to the sum of any two natural frequencies, combination resonances occur. The effects of damping parameters on the regions of three parametric resonances are discussed.