• Journal of the Korean Society of Marine Environment & Safety
• /
• v.19 no.4
• /
• pp.382-390
• /
• 2013

The efforts for improving 'Maritime Traffic Safety Assessment Scheme(MTSA scheme)' have continued to the present. At this point, it needs to establish sound MTSA scheme to proceed acceleration step through the comprehensive review and systematic approach. In this study, it aimed to design of Metaevaluation Model for the comprehensive analysis of MTSA scheme with applying theory of the Metaevaluation, that is the evaluation of evaluation. To put it concretely, This research draw a basic model by using Metaevaluation methods like as literature studies, expert reviews, surveys and etc. and proposed a available 'PIP'OU' Metaevaluation Model through verified validity and reliability. This PIP'OU Model is the first proposed Metaevaluation Model in maritime field and it is expected to be used as framework to draw up improvement measure with deriving problem for the MTSA scheme.

• Tunnel and Underground Space
• /
• v.25 no.3
• /
• pp.255-263
• /
• 2015

Explosive blasting is a very useful tool for mining and civil engineering applications. It, however, may cause severe environmental hazards on adjacent structures due to blasting impact. Blast engineers try to make optimum blast design to provide efficient performance and to minimize the environmental impact as well. It requires a pre-assessment of the impacts resulting from the blasting operation in design stage. One of the common procedures is to evaluate the proposed blast pattern through a series of test blasting in the field. Another approach is to evaluate the possible environmental effects using the numerical methods. There are a number of input parameters to be prepared for the numerical analysis. Some of them are well understood, while some are not. This paper presents some results of sensitivity analysis of the basic input parameters in numerical modelling of blasting problems so as to provide sound understanding of the parameters and some guidelines for input preparation.

• Journal of Sensor Science and Technology
• /
• v.11 no.3
• /
• pp.171-182
• /
• 2002

The differential electromagnetic transducer for IME(implantable middle ear) system, which have two small permanent magnets glued with the same pole facing each other in the coil, has high vibration efficiency and does not influenced by external magnetic field. In this paper, using finite element method, highly efficient structure of the transducer was proposed and vibration force of the transducer was calculated by electromagnetic theory. And the necessary vibration force of transducer to transmit the sound signal to inner ear when the transducer is attached at stapes was calculated and the design parameters of the transducer were investigated. Using the parameters, the differential electromagnetic transducer was manufactured in small size to implant in confined human middle ear. And it was examined by unloaded and loaded vibration experiment using temporal bone sampled from cadaver.

• International Journal of Computer Science & Network Security
• /
• v.21 no.12
• /
• pp.269-279
• /
• 2021

In the current conditions of world socio-economic development, the strategic support of the process of managing the development of universities has become a particularly important area. Strategic management requires reliable information and analytical support in the form of sound descriptions of strategic directions of development, assumptions, and forecasts. The purpose of the study is to substantiate and elaborate the crucial causes in the strategic management of university's development and to suggest the coherent prospects for advancements. The data analysis was performed using descriptive methods to identify the most significant causes that affect the university's strategic development; the expert assessment was used to rank the factors, ultimately to assess each factor that affects to some extent the university's strategic development; the abstract-logical method was used to ground the positive impact of computer technologies and e-learning on the strategic development of a university and to formulate proposals for its further progress. The main results provided in the given paper showed that significant and most important strategic cause of university's development lies in the field of improving the quality of education, expanding access to educational services based on computer technology and its functionality. In turn, its widespread use at all stages of the educational process allows providing a number of advancements for universities in strategic prospects.

• Fashion & Textile Research Journal
• /
• v.25 no.3
• /
• pp.366-378
• /
• 2023

Recently, the use of one-person broadcast content for special makeup videos has gained momentum. This study aims to analyze the factors preferred by various age groups as the total number of clicks increase on special makeup videos. It also aims to provide beauty creators with useful data to help them create videos that generate more clicks based on the derived elements. We analyzed previous studies and divided the subjective indicators into place & accessories, editing, model (Y/N), contents and field, and characteristics of the creators. We analyzed top 5 videos from among 257 videos uploaded before July 1, 2020. The subjective indicators were analyzed through a questionnaire survey attempted by 60 respondents in their 10-30s from Jeollanam-do and Gwangju between July 20 to August 31, 2020. The questions majorly focused on intimacy, attractiveness, professionalism, informativity, and playfulness. We analyzed the collected data using SPSS 21.0, and obtained the following results: Informativity, professionalism, attractiveness, and playfulness were considered to be more influential by those aged 10 to 30 years. In particular, factors like visual elements, linguistic characteristics, experts, background music and sound effects, celebrities, product information, and knowhow were most preferred. In fact, it was easy to make videos using these elements. The above results confirmed the utility of such data for beauty-creators-to-be in creating videos that generate more clicks.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.50 no.2
• /
• pp.64-75
• /
• 2022

The purpose of this study is to illuminate the meaning of the soundscapes of two bells, Daeheung-dong Cathedral and Sungsimdang in Eunghang-dong, which are landmarks and attractions in the historic downtown of Daejeon. The study was conducted through field research and recordings, as well as literature studies of related documents and soundscape theory. Daejeon city was developed along with Daejeon Railway Station during the Japanese colonial period in the early 20th century. As the Chungnam Provincial Office moved to Daejeon, Daeheung-dong and Eunhang-dong in Jung-gu, located near Daejeon Station, developed significantly and formed the city centre. As major administrative agencies moved to Seo-gu in the 1990s, the downtown area of Daejeon was on a path of decline, and the decline accelerated with the development of Sejong city. Meanwhile, Daeheung-dong Cathedral and Sungsimdang, founded by refugees during the Korean War, firmly protected the historic downtown area of Daejeon, where the natives left. Daeheung-dong Cathedral, established during the Japanese colonial period, is a local landmark with a history of 100 years in 2019. Sungsimdang, which was created with the backdrop of the Korean War, is also a historical and cultural asset with a history of 60 years and a local landmark selected as the No. 1 tourist attraction in Daejeon. This research, which started from the sound of the bells of Daeheung-dong Cathedral, heard even in the neighboring residential areas, led to the discovery of the bells of Sungsimdang in Eunhang-dong, located across the street. In this paper, the bells of Daeheung-dong Cathedral and Eunhang-dong Sungsimdang have characteristics of soundmarks according to R. Murray Schafer's soundscape sound category. Furthermore, this paper attempted to analyze the meaning of the two bells according to the relatively recent EU soundscape definition. These two bells are signal sounds at the surface level, but are the sound marks of the historic downtown area of Daejeon at the deep level. Although there are outward differences in size, scale, frequency, and famousness, these two bells share a meaning in terms of locality and good influence with the historicity and spatiality of a special relationship. The implication of this study is that the two places should be preserved as local historical and cultural assets not only as visual landmarks but also as sound marks in the urban regeneration or urban development of Jung-gu, Daejeon.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.20 no.12
• /
• pp.844-861
• /
• 2008

The papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during the year of 2007 have been reviewed. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environments. The conclusions are as follows. (1) The research trends of fluid engineering have been surveyed as groups of general fluid flow, fluid machinery and piping, etc. New research topics include micro nano fluid, micropump and fuel cell. Traditional CFD was still popular and widely used in research and development. Studies about fans and pumps were performed in the field of fluid machinery. Characteristics of flow and fin shape optimization are studied in the field of piping system. (2) The research works on heat transfer have been reviewed in the field of heat transfer characteristics, heat exchangers, and desiccant cooling systems. The research on heat transfer characteristics includes thermal transport in pulse tubes, high temperature superconductors, ground heat exchangers, fuel cell stacks and ice slurry systems. For the heat 'exchangers, the research on pin-tube heat exchanger, plate heat exchanger, condensers and gas coolers has been cordially implemented. The research works on heat transfer augmenting tubes have been also reported. For the desiccant cooling systems, the studies on the design and operating conditions for desiccant rotors as well as performance index are noticeable. (3) In the field of refrigeration, many papers were presented on the air conditioning system using CO2 as a refrigerant. The issues on the two-stage compression, the oil selection, and the appropriate oil charge were treated. The subjects of alternative refrigerants were also studied steadily. Hydrocarbons, DME and their mixtures were considered and various heat transfer correlations were proposed. (4) Research papers have been reviewed in the field of building facilities by grouping into the researches on heat and cold sources, air conditioning and air cleaning, ventilation and fire research including tunnel ventilation, flow control of piping system, and sound research with drain system. Main focuses have been addressed to the promotion of efficient or effective use of energy, which helps to save energy and results in reduced environmental pollution and operating cost. (5) Studies were mostly focused on analyzing the indoor environment in various spaces like cars, old tombs, machine rooms, and etc. in an architectural environmental field. Moreover, subjects of various fields such as the evaluation of noise, thermal environment, indoor air quality and development of energy analysis program were researched by various methods of survey, simulation, and field experiment.

• The Journal of the Acoustical Society of Korea
• /
• v.30 no.1
• /
• pp.22-32
• /
• 2011

The present study examined the effects of the complexity of the 3D models on the results of acoustic simulation which is the predominant tool of the acoustical design of buildings. Also, the effects of the 3D model on the auralized sounds were investigated. In order to carry out the study, four 3D models with different levels of complexity were introduced for a real auditorium which have different numbers of surfaces in the persuit of the guidance of odeon room acoustic software. The set-up of models was also based on the level of transition order of the program. And the acoustic experiments were performed measuring room acoustic parameters including SPL, RT, C80, D50. Acoustic computer simulations were performed using four different models. Then, the results of the computer modeling were compared with the measured acoustical parameters. In addition, sound sources were recorded in the field and auralized sounds were made in convolution with the impulse source made from acoustic modeling. Then, subjective tests were undertaken using auralized sounds. As the results, it was found that the result of the acoustic simulation were closer to the real room acoustic properties when 3D model was more particularly made. For the subjective test, the listening materials were acknowledged as similar with the real sound source when more complex 3D model was used. Then, it could be concluded that the complexity of the 3D model affects the results of the acoustic modeling as well as subjective tests.

• Proceedings of the Acoustical Society of Korea Conference
• /
• spring
• /
• pp.469-474
• /
• 2002

In recent years, modularization of engine parts has increased the application of plastic products in air intake systems. Plastic intake manifolds provide many advantages including reduced weight, contracted cost, and lower intake air temperatures. These manifolds, however, have some weakness when compared with customary aluminium intake manifolds, in that they have low sound transmission loss because of their lower material density. This low transmission loss of plastic intake manifolds causes several problems related to flow noise, especially when the throttle is opened quickly. The physical processes, responsible for this flow noise, include turbulent fluid motion and relative motion of the throttle to the airflow. The former is generated by high-speed airflow in the splits between the throttle valve and the inner-surface of the throttle body and surge-tank, which can be categorized into the quadrupole source. The latter induces the unsteady force on the flow, which can be classified into the dipole source. In this paper, the mechanism of noise generation from the turbulence is only investigated as a preliminary study. Stochastic noise source synthesis method is adopted for the analysis of turbulence-induced, i.e. quadrupole noise by throttle at quick opening state. The method consists of three procedures. The first step corresponds to the preliminary time-averaged Navier-Stokes computation with a $k-\varepsilon$ turbulence model providing mean flow field characteristics. The second step is the synthesis of time-dependent turbulent velocity field associated with quadrupole noise sources. The final step is devoted to the determination of acoustic source terms associated with turbulent velocity. For the first step, we used market available analysis tools such as STAR-CD, the trade names of fluid analysis tools available on the market. The steady state flows at three open angle of throttle valve, i.e. 20, 35 and 60 degree, are numerically analyzed. Then, time-dependent turbulent velocity fields are produced by using the stochastic model and the flow analysis results. Using this turbulent velocity field, the turbulence-originated noise sources, i.e. the self-noise and shear-noise sources are synthesized. Based on these numerical results, it is found that the origin of the turbulent flow and noise might be attributed to the process of formulation and the interaction of two vortex lines formed in the downstream of the throttle valve. These vortex lines are produced by the non-uniform splits between the throttle valve and inner cylinder surface. Based on the analysis, we present the low-noise design of the inner geometry of throttle body.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.12
• /
• pp.2352-2360
• /
• 2011

In this paper, we introduce a comprehensive design methodology of Radial Basis Function Neural Networks (RBFNN) that is based on mechanism of clustering and optimization algorithm. We can divide some clusters based on similarity of input dataset by using clustering algorithm. As a result, the number of clusters is equal to the number of nodes in the hidden layer. Moreover, the centers of each cluster are used into the centers of each receptive field in the hidden layer. In this study, we have applied Fuzzy-C Means(FCM) and K-Means(KM) clustering algorithm, respectively and compared between them. The weight connections of model are expanded into the type of polynomial functions such as linear and quadratic. In this reason, the output of model consists of relation between input and output. In order to get the optimal structure and better performance, Particle Swarm Optimization(PSO) is used. We can obtain optimized parameters such as both the number of clusters and the polynomial order of weights connection through structural optimization as well as the widths of receptive fields through parametric optimization. To evaluate the performance of proposed model, NXT equipment offered by National Instrument(NI) is exploited. The situation awareness system-related intelligent model was built up by the experimental dataset of distance information measured between object and diverse sensor such as sound sensor, light sensor, and ultrasonic sensor of NXT equipment.