• 한국조경학회지
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• 제26권3호
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• pp.19-33
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• 1998

The primary objective of this research was to develop optimal models for masking the road traffic noise with the sound of a waterfall at urban small green spaces. Noise levels were measured at 8 roadside green spaces in SEOUL and questionnaires were randomly distributed to 40 users for evaluating the noise at each site at the same time. College students participated in the experiment for the development of masking models and the developed models were tested by users at 2 green spaces. The major results are as follows ; 1. Traffic noises ranged from 65dBto 70 dB. Users' satisfaction with the noise became considerably low on the basis of 60 dB and it was highly related to noise level. 2. Noise was a main factor to depreciate the amenity of green spaces where its level was more than 60 dB and so it neds to be excluded or reduced the traffic noise at the process of design. 3. Masking effects kept constant independent of the spatial location of masker on condition that masker levels were equal. It was effective when masker was 5-10dB greater than noise level which was masked. 4. As noise level went up, satisfaction ratings about the masked noise became low but masking effects increased in proportion to its level. 5. It was proved that the models were valid through the field experiment.

• 융복합기술연구소 논문집
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• 제5권2호
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• pp.33-36
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• 2015

In this paper, the development history of random packings for several generations was briefly introduced. We demonstrate the application of 3D printing to the fabrication of Pall rings, directly using computer aided design (CAD) models. The CAD was used to design Pall rings with different number of blades. The models were then printed by using UV curing of acrylonitrile-butadiene-styrene (ABS) resins. The results show that 3D printing is a promising method for producing precisely controlled packing materials. It is also expected that 3D printing is helpful for the fundamental studies of highly efficient packing materials with complex geometrical shapes.

• Bulletin of the Korean Chemical Society
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• 제32권5호
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• pp.1604-1612
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• 2011

We developed three-dimensional quantitative structure activity relationship (3D-QASR) models for 17 adamantyl derivatives as P-glycoprotein (P-gp) inhibitors. Eighteen different partial charge calculation methods were tested to check the feasibility of the 3D-QSAR models. Best predictive comparative molecular field analysis (CoMFA) model was obtained with the Austin Model 1-Bond Charge Correction (AM1-BCC) atomic charge. The 3D-QSAR models were derived with CoMFA and comparative molecular similarity indices analysis (CoMSIA). The final CoMFA model ($q^2$ = 0.764, $r^2$ = 0.988) was calculated with an AM1-BCC charge and electrostatic parameter, whereas the CoMSIA model ($q^2$ = 0.655, $r^2$ = 0.964) was derived with an AM1-BCC charge and combined steric, electrostatic, hydrophobic and HB-acceptor parameters. Leave-five-out (LFO) cross-validation was also performed, which yielded good correlation coefficient for both CoMFA (0.801) and CoMSIA (0.656) models. Robustness of the developed models was checked further with 1000 run bootstrapping analyses, which gave an acceptable correlation coefficient for CoMFA (BS-$r^2$ = 0.997, BS-SD = 0.003) and CoMSIA (BS-$r^2$ = 0.996, BS-SD = 0.018).

• 한국기계가공학회지
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• 제18권8호
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• pp.91-97
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• 2019

A method for generating 3D solid models and drawings for a rotor in the steam turbine is proposed. One of the most important design steps is generating the drawing for manufacturing it. This step is a very routine and time-consuming job because each drawing is composed of several kinds of views and many dimensions. To achieve automation for this activity, rotor profiles are composed of 2D entity groups with attributes. Based on this, the improved design process is developed as follows. First, the rotor profiles can be selected by searching for 2D entity groups using the related attributes. Second, the profiles are connected sequentially so that an entire rotor profile is determined. The completed profile is used to generate 2D drawings automatically, especially views, dimensions, and 3D models. The proposed method is implemented using a commercial CAD/CAM system, Unigraphics, and API functions written in C-language and applied to the rotor of steam turbines. Some illustrative examples are provided to show the effectiveness of the proposed method.

• 대한조선학회논문집
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• 제56권1호
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• pp.66-74
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• 2019

In the field of shipbuilding design, the use of 3D CAD is becoming commonplace, and most of the large shipyards are conducting 3D design. However at the production site, workers are still working on 2D drawings rather than 3D models. This tendency is even worse in small-scale shipyards and block manufacturing shops. Particularly, in a manufacturing shop that is engaged in the outsourcing of blocks, it may not be possible to provide 3D model. However, the demand for 3D models in the production field is steadily increasing. Therefore, it would be helpful if 3D model could be generated from a 2D drawing. In this paper, we propose a method to extract template and unfolded surface shape information from shell template offset drawing using computer vision technology. Also a 3D surface model was reconstructed and visualized from the extracted information. The result of this study is thought to be helpful in the work environment where 3D model information can not be obtained.

• 한국의류산업학회지
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• 제15권2호
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• pp.247-255
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• 2013

This study develops size sections and specifications for females 7-18 years old. The specifications will contribute to the development of precise virtual models that represent basic data for the size alteration of 3D virtual models. A total of 33 items from the $5^{th}$ Size Korea data set were adopted and analyzed. Two representative factors (Obesity and Height Factors) were identified through a factor analysis of the 33 items. Waist circumference and stature were selected as representative variables for Obesity and Height Factors, respectively, and conducted cross tabulations between waist circumference and height for the age groups of 7-12 and 13-18 year-olds. Size sections were developed for the development of 3D models based on the results. A regression analysis then developed size specifications for each section with independent variables of waist circumference and height as well as dependent variables of reference body size. Subsequently, Obesity Factors were better explained by waist circumference and Height Factors were better explained by stature. Finally, size specifications for each section were developed.

• 한국CDE학회논문집
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• 제4권2호
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• pp.87-99
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• 1999

We developed a Part Information Brokering System, namely PIBS, that can inter-link part suppliers and buyers using WWW(World Wide Web). The major contribution of this paper is that the system provides a 3D collaboration environment that enables multiple users to share the same workspace where they cooperatively manipulate part features in real time. PIBS carries out two major functions: one to maintain part data in a part library, and the other to provide the means for the clients to cooperate. An object-oriented database is used for the part library which stores apart information registered by part suppliers. VRML(Virtual Reality Modeling Language) the ISO standard for 3D visualization on WWW, is used to represent 3D part models. Several Java programs have been implemented to support synchronous and a synchronous communication of the 3D models. Once the users are interconnected through the system, a user's manipulation of part objects is transparently and instantaneously transmitted to the others. This means that all the participants can are the same view and movement of the 3D part models. Since the system is developed using a Java applet-server architecture, it requires no additional software other than standard web browser. The prototype system has been successfully implemented, and demonstrated its applicability to virtual 3D part information sharing.

• 한국CDE학회논문집
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• 제8권2호
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• pp.122-132
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• 2003

STEP AP218 has a standard schema to represent the structural model of a midship section. While it helps to exchange ship structural models among heterogeneous automation systems, most shipyards and classification societies still exchange information using 2D paper drawings. We propose a feature parameter input method to generate a 3D STEP model of a ship structure from 2D drawings. We have analyzed the ship structure information contained in 2D drawings and have defined a data model to express the contents of the drawing. We also developed a QUI for the feature parameter input. To translate 2D information extracted from the drawing into a STEP AP2l8 model, we have developed a shape generation library, and generated the 3D ship model through this library. The generated 3D STEP model of a ship structure can be used to exchange information between design departments in a shipyard as well as between classification societies and shipyards.

• Imaging Science in Dentistry
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• 제34권1호
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• pp.13-18
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• 2004

Purpose : This study was to evaluate the influence of slice thickness of computed tomography (CT) and rapid protyping (RP) type on the accuracy of 3-dimensional medical model. Materials and Methods: Transaxial CT data of human dry skull were taken from multi-detector spiral CT. Slice thickness were 1, 2, 3 and 4 mm respectively. Three-dimensional image model reconstruction using 3-D visualization medical software (V-works /sup TM/ 3.0) and RP model fabrications were followed. 2-RP models were 3D printing (Z402, Z Corp., Burlington, USA) and Stereolithographic Apparatus model. Linear measurements of anatomical landmarks on dry skull, 3-D image model, and 2-RP models were done and compared according to slice thickness and RP model type. Results: There were relative error percentage in absolute value of 0.97, 1.98,3.83 between linear measurements of dry skull and image models of 1, 2, 3 mm slice thickness respectively. There was relative error percentage in absolute value of 0.79 between linear measurements of dry skull and SLA model. There was relative error difference in absolute value of 2.52 between linear measurements of dry skull and 3D printing model. Conclusion: These results indicated that 3-dimensional image model of thin slice thickness and stereolithographic RP model showed relative high accuracy.

• 농약과학회지
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• 제12권1호
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• pp.9-17
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• 2008

일련의 새로운 cyclohexanone 유도체(5-benzofuryl-2-[1-(alkoxyimino)alkyl]-3-hy-droxycyclohex-2-en-1-ones)와 벼(Oryza sativa L.) 및 돌피(Echinochloa crus-galli)에 대한 제초활성과의 정량적인 구조-활성관계(QSARs)를 2D-QSAR 및 HQSAR 방법으로 검토하였다. 일반적으로 HQSAR 모델이 2D-QSAR 모델보다 예측성과 적합성이 좋았다. 2D-QSAR II 모델로부터 돌피의 제초활성은 분자의 Balaban 지수(BI)와 $R_1$ 및 $R_3$-기의 소수성에 의존적이었다. 또한, HQSAR IV 모델에 따라 $R_3=ethyl$ 기가 벼의 제초활성에 기여하는 반면에 5-(cyclohex-3-enyl)-2,3-dihydrobenzofuran 고리 부분은 두 초종의 제초활성에 기여하지 않았다.