• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.2
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• pp.521-528
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• 2013

Urban drainage systems are generally designed as open channel flow. The system, however, shows a partially surcharged flow in its body, especially at junctions or manholes. Thus, a special case of this condition needs to be explained as pressurized flow condition for designing the sewer system. This study considered the surcharged manhole flows during an unexpected rainfall event or an excess of design frequency. Overflows from surcharged manholes and urban flooding can occur from the effect of surcharged flows. Thus, sewer systems should be designed with the concept of open channel flow and pressurized flow. Also, energy losses in a manhole need to be considered. The aim of this study is to develop the numerical model which can evaluate the effect of the energy losses at the manhole. The numerical model was verified and compared with hydraulic model and SWMM. The results showed that the water depth of numerical model was in good agreement with hydraulic model at the each manhole. However, the SWMM underestimated the water depth because that model ignored the energy losses at manholes. Thus, the developed numerical model in this study could be a useful tool for the assessment of a conveyance of urban drainage system.

• Journal of the Korean Magnetics Society
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• v.21 no.2
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• pp.77-82
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• 2011

The use of soft magnetic materials have been increasing in the various industrial fields according to the increasing demand for high performance, automatic, miniaturing equipments in the recent our life. In this study, we investigated the effect of factors on the core loss and magnetic properties of electrical steel and soft magnetic composites. Furthermore, we reviewed the major efforts to reduce the core loss and improve the soft magnetic properties in the two main soft magnetic materials. Domain purification which results from reduced density of defects in cleaner electrical steels is combined with large grains to reduce hysteresis loss. The reduced thickness and the high electrical conductivity reduce the eddy current component of loss. Furthermore, the coating applied to the surface of electrical steel and texture control lead to improve high permeability and low core loss. There is an increasing interest in soft magnetic composite materials because of the demand for miniaturization of cores for power electronic applications. The SMC materials have a broad range of potential applications due to the possibility of true 3-D electromagnetic design and higher frequency operation. Grain size, sintering temperature, and the degree of porosity need to be carefully controlled in order to optimize structure-sensitive properties such as maximum permeability and low coercive force. The insulating coating on the powder particles in SMCs eliminates particle-to-particle eddy current paths hence minimizing eddy current losses, but it reduces the permeability and to a small extent the saturation magnetization. The combination of new chemical composition with optimum powder manufacturing processes will be able to result in improving the magnetic properties in soft magnetic composite materials, too.

• Journal of Sasang Constitutional Medicine
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• v.17 no.1
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• pp.67-83
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• 2005

1. Objectives The purpose of this study lies on the objectification of the Sasang Constitutional diagnosis. This study was analyzing the constitutional characteristic of adult men voices by PSSC-2004. 2. Methods The study was conducted on the subjects inputted /a/ 2.5-3 sec of 231 adult men voices to PSSC-2004. The statistical analyses are applied to three groups: total group, under 55 year-old group, over 55 year-old group. The group of total 231 was composed with 5 Taeyangins, 32 Soyangins, 102 Taeumins and 92 Soeumins. The under 55 years old group was composed with 4 Taeyangins, 23 Soyangins, 83 Taeumins and 77 Soeumins. The over 55 year-old group was composed with 1 Taeyangin, 9 Soyangins, 19 Taeumins and 15 Soeumins. 3. Results 1) In total group, the Soeumin's mean value of center pitch(4)$(1,000{\sim}2,000Hz)$ was significantly high compared with the others (P=0.034). 2) In total group, the Soeumin's group 3 APQ was significantly low compared with the others (P=0.042). 3) In under 55 year-old group, the Soeumin's center value of center pitch 4$(1,000{\sim}2,000Hz)$ was significantly high compared with the others (P=0.025) 4) In over 55 year-old group, no statistical significance was found between the Taeyangin, Soyangin, Taeumin and Soeumin. 4. Conclusions In under 55 year-old group, Soeumin's voice showed high pitched sound (clearness) at the low frequency (1000-2000Hz). In over 55 year-old group, there is no significant differences. This fits in with that 'Soeumin's voice is 'Yu-tone' born by 'Shang-tone', very short and high.' 'Yu-tone' corresponds to 'Ra' and witch is highest among Gong, Shang, Gao, Chi and Yu. This is related with the appearance that the Soeumin's voice is weak, thin and high tone. Therefore it is supposed that Soeumin adult men's voices are thick, and there are vibrations of the ending. It is accepted one of the Soeumin's characters like as a mild tremor of limbs and deep breath caused by Soeumin's Qi-deficiency. This outcome accords with the theory that Soeumin's Qi is less than the Other constitutions.

• Journal of Acupuncture Research
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• v.27 no.1
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• pp.65-74
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• 2010

Objectives : This study was to investigate the effects of Cervi Pantotrichum Cornu Pharmacopuncture and Bovis calculus Fel Ursi Pharmacopuncture on autonomic nervous system with Heart Rate Variability(HRV). Purpose of the trial was to observe what influence Cervi Pantotrichum Cornu Pharmacopuncture and Bovis calculus Fel Ursi pharmacopuncture have on the autonomic nervous system. Methods : 40 healthy male volunteers were divided into two experimental groups, such as Cervi Pantotrichum Cornu Pharmacopuncture group and Bovis calculus Fel Ursi Pharmacopuncture group. Study design was a randomized, double-blind clinical trial. 20 subjects in one experimental group were injected Cervi Pantotrichum Cornu Pharmacopuncture, 20 subjects in other experimental group were injected hydrolyzed Bovis calculus Fel Ursi Pharmacopuncture at GB21(Kyonjong). We measured HRV 7 times : baseline measurement and every 5 minutes for 30 minutes after injection. The SPSS 15.0 for Windows was used to analyze the data by the paired t-test(in group) and independent sample t-test(between the groups). Results A. Time Domain Analysis 1. Analysis of Mean HRV, SDNN and Complexity After injection of Cervi Pantotrichum Cornu Pharmacopuncture, Mean HRV was significantly decreased all the times after injection. SDNN was significantly increased at immediate and 25 minute after injection. Complexity was significantly decreased only at 15 minute after injection. After injection of Bovis calculus Fel Ursi Pharmacopuncture, Mean HRV was significantly decreased all the times after injection. Complexity was significantly decreased at 15 minutes after injection. 2. Analysis of HRV index, pNN50 After injection of Cervi Pantotrichum Cornu Pharmacopuncture, HRV index was significantly increased immediately after injection. pNN50 was significantly decreased at immediately, 20 and 25 minutes after injection. After injection of Bovis calculus Fel Ursi Pharmacopuncture, HRV index was significantly increased immediately after injection. pNN50 was significantly decreased at immediate and 25 minutes after injection. B. Frequency Domain Analysis 1. Analysis of Ln(TP), Ln(HF), Ln(LF), Ln(VLF) After injection of Cervi Pantotrichum Cornu Pharmacopuncture, Ln(TP) was significantly increased at immediate and 25 after injection. Ln(HF) was significantly increased all the times after injection. Ln(LF) was significantly increased at 15, 20 and 25 minutes after injection. Ln(VLF) was significantly increased at immediate and 25 minutes after injection. After injection of Bovis calculus Fel Ursi Pharmacopuncture, Ln(TP) was significantly increased at immediately and 25 after injection. Ln(LF) was significantly increased at 20 and 25 minutes after injection. Ln(VLF) was significantly increased at immediate and 25 minutes after injection. Conclusions : We results suggest that Cervi Pantotrichum Cornu Pharmacopuncture and Bovis calculus Fel Ursi Pharmacopuncture in healthy adult men tend to activate the autonomic nervous system and sympathetic nervous system within normal range.

• Journal of Digital Convergence
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• v.15 no.7
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• pp.147-157
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• 2017

Recently, ICT Retail Convergence(IRC) has been rapidly increasing to improve consumer satisfaction and consumer experience. In this paper, we aim to diagnose IRC from consumers' point of view by reviewing the present status and value of IRC according to consumer purchase decision making process. Based on the previous studies in retail industry, we classified IRC into 4 types: Experience-specific tech(Virtual Reality and Augmented Reality); Information-specific tech(Artificial Intelligence and Big Data); Location-based tech(Radio Frequency Identification and Beacon); Payment-related tech(Fin-tech and Biometrics). Next, we found that there is a difference in value provided to consumers according to the type of technology, analysing the value by consumer purchase decision making process. This study can be useful to introduce IRC for improving consumer satisfaction as well as ICT and Retail. Also, it can be basic data for future technology studies with a consumer perspective.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.2
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• pp.7-13
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• 2011

This paper presents a Time-to-Digital Converter which is a key block of an All-Digital Phase Locked Loop. In this work, a Vernier Delay Line is added in a conventional Gated Ring Oscillator, so it could get multi-phases and a high resolution. The Gated Ring Oscillator uses 7 unit delay cell, the Vernier Delay Line is used each delay cell. So proposed Time-to-Digital Converter uses total 21 phases. This Time-to-Digital Converter circuit is designed and laid out in $0.13{\mu}m$ 1P-6M CMOS technology. The proposed Time-to-Digital Converter achieves 26ps resolution, maximum input signal frequency is 100MHz and the digital output of proposed Time-to-Digital Converter are 8-bits. The proposed TDC detect 5ns phase difference between Start and Stop signal. A power consumption is 8.4~12.7mW depending on Enable signal width.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.1
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• pp.91-101
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• 2008

Structural analysis models to develop live load distribution factors of simply supported prestressed concrete I-girder bridge should have the precision of the analysis results as well as modeling simplicity. This is due to the numerous frequency of structural analysis needed while developing live load distribution factors. In this study, an appropriate structural analysis model is selected by comparing previous researchs studies and models used in practical design. Also, the influence by the flexural stiffness of barrier and diaphragm on the live load distribution had been analyzed through comparing the numerical analysis and experimental tests. As a result, the model that the eccentric girder and the barrier and diaphragm are connected to the deck plate was appropriate in satisfying both accuracy and simplicity for structural analysis of simply supported prestressed concrete I-girder bridge. However, the barrier was analyzed to have insignificant influence on the live load distribution in spite of its variation of stiffness. The eccentric diaphragm showed little influence at 25% or higher of flexural stiffness. From the results, a model that the girder is rigidly connected to the deck plate in consideration of the eccentricity, the barrier is ignored and the whole section of diaphragm is supposed to be valid without eccentricity is decided as the most appropriate structural model to develop the live load distribution factors of simply supported prestressed concrete I-girder bridge in this study.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.6
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• pp.367-374
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• 2019

We investigate the effect of soil-structure interaction (SSI) on the response of LNG storage tanks to vertical seismic excitation depending on the type of foundation. An LNG storage tank with a diameter of 71 m on a clay layer with a thickness of 30 m upon bedrock, was selected as an example. The nonlinear behavior of the soil was considered in an equivalent linear method. Four types of foundation were considered, including shallow, piled raft, and pile foundations (surface and floating types). In addition, the effect of soil compaction within the group pile on the seismic response of the tank was investigated. KIESSI-3D, an analysis package in the frequency domain, was used to study the SSI and the stress in the outer tank was calculated. Based on an analysis of the numerical results, we arrived at three main conclusions: (1) for a shallow foundation, the vertical stress in the outer tank is less than the fixed base response due to the SSI effect; (2) for foundations supported by piles, the vertical stress can be greater than the fixed base stress due to the increase in the vertical impedance due to the piles and the decrease in radiation damping; and (3) soil compaction had a miniscule impact on the seismic response of the outer tank.

• The Journal of Korean Academy of Prosthodontics
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• v.48 no.1
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• pp.61-68
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• 2010

Purpose: This article attempted to determine the factors affecting the preload and screw loosening. Methods: Available clinical studies from 1981 to 2008 from the PUBMED that presented screw loosening data and review articles regarding screw joint stability were evaluated. Eleven studies dealing the biomechanical principles of the screw mechanics were reviewed. Moreover, the results of our data were included. Results: The frequency of screw loosening was consequently reduced due to the advancement in torque tightening with torque wrench, screw material, coating technique for reducing the frictional force, and thread design, etc. If preload in the screw falls below a critical level, joint stability may be compromised, and the screw joint may fail clinically. The types of fatigue failure of screw were divided to adhesive wear, plastic deformation, and screw fracture. Conclusion: An optimum preload is essential to the success of the implant-abutment complex. To maintain optimum preload, using a torque wrench and re-tightening at recall time were needed.

• Journal of The Korean Association For Science Education
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• v.34 no.6
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• pp.549-558
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• 2014

Integrated concepts that are broad enough to embrace facts, principles, laws, and concepts of multiple disciplines could become the core of integrated education. Integrated concept-centered education enables effective and practical learning. In this study, the Delphi Method was implemented targeting experts in science (physics, life science, chemistry, and earth science) and humanities (history, geology, economics, ethics, and politics) to find out the integrated concept that can be used to design the concept-centered integrated education in the Republic of Korea. 124 experts participated in this survey. Delphi survey was conducted for three rounds. In the first round, an open questionnaire was given to experts to collect feasible integrated concepts in each major field. Then, in the second round experts were asked to select integrated concepts that could be used practically in the field of their major. In the third round, the integrated concept with selection frequency over medium value were given. They were asked to evaluate the applicability of integrated concepts by using the Likert-scale questionnaire. Through this process, content validity was analyzed. As a result, five integrated concepts (change, interaction, space-time, energy, and equilibrium) were selected for the inter-science integration. And thirteen integrated concepts (conflict, community, relationship, structure, power, diversity, culture, change, society, interaction, freedom, justice, and equality) were chosen for the inter-humanities integration. Finally, for the science-humanities integration, seven integrated concepts (structure, diversity, change, interaction, cycle, system, and environment) were determined.