• 설비공학논문집
• /
• 제12권4호
• /
• pp.404-413
• /
• 2000

Environmental chamber (EC) is an experimental facility used to analyze the characteristics of thermal response of testing objects by the artificial control of weather conditions. The EC in KIER can simulate the weather conditions by the control of temperature, humidity, and solar radiation. A two-storied testing building is located inside of EC. For the exact thermal response analysis of testing building, monthly or yearly scheduled operations are necessary. Although this long term operation gives the exact experimental data, it requires a high operational cost, long duration, and lots of manpower. Therefore it is necessary to perform the shortened experiments without sacrificing the validity of the obtained results. Since the characteristics of thermal response from the shortened experiments are different from the full time results, the analytical method to analyze the thermal response from the shortened experiments to estimate a full times results is developed in this study. The thermal response of testing building is performed using commercial software TRNSYS.

• Smart Structures and Systems
• /
• 제13권6호
• /
• pp.943-957
• /
• 2014

When subjected to fatigue loading, the main failure mode of partially prestressed concrete (PPC) structure is the fatigue fracture of tensile reinforcement. Therefore, monitoring and evaluation of the steel stresses/strains in the structure are essential issues for structural design and healthy assessment. The current study experimentally investigates the possibility of using fiber Bragg grating (FBG) sensors to measure the steel strains in PPC beams in the process of fatigue loading. Six full-scale post-tensioned PPC beams were exposed to fatigue loading. Within the beams, the FBG and resistance strain gauge (RSG) sensors were independently bonded onto the surface of tensile reinforcements. A good agreement was found between the recorded results from the two different sensors. Moreover, FBG sensors show relatively good resistance to fatigue loading compared with RSG sensors, indicating that FBG sensors possess the capability for long-term health monitoring of the tensile reinforcement in PPC structures. Apart from the above findings, it can also be found that during the fatigue loading, there is stress redistribution between prestressed and non-prestressed reinforcements, and the residual strain emerges in the non-prestressed reinforcement. This phenomenon can bring about an increase of the steel stress in the non-prestressed reinforcement.

• International Journal of Air-Conditioning and Refrigeration
• /
• 제9권3호
• /
• pp.18-26
• /
• 2001

Environmental chamber (EC) is an experimental facility used to analyze the characteristics of thermal response of testing objects by the artificial control of weather conditions. The EC in KIFR can simulate the weather conditions by the control of temperature, humidity, and solar radiation. A two-storied testing building is located inside EC. For the exact thermal response analysis of testing building, monthly or yearly scheduled operations are necessary. Although this long term operation gives the exact experimental data, it requires a high operational cost, long duration, and lots of manpower. Therefore it is necessary to perform the shortened experiments without sacrificing the validity of the obtained results. Since the characteristics of thermal response from the shortened experiments are different from the full time results, the analytical method to analyze the thermal response from the shortened experiments to estimate a full times results is developed in this study The thermal response of testing building is performed using commercial software TRNSYS.

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권3호
• /
• pp.897-900
• /
• 2012

Cervical cancer resulting from prior infection with human papillomavirus (HPV) is a significant public health threat against young Japanese women. A national immunization plan to vaccinate 13~16 year old female students against HPV infection has been started in Japan since 2010, and may reach almost full coverage by the end of 2012. Older age females who may already be sexually active are not targeted by this plan but should follow safer sex practices as well as periodic screening of the cervix cytology to reduce their risk of developing cervical cancer. HPV vaccination alone does not offer full protection either, because only some HPV types are covered by the vaccines and the long-term efficacy of the vaccines has not been determined yet. Therefore, we did a survey at an international university in Japan to study the knowledge and attitude of female college students towards prevention of cervical cancer, to examine the age when they start sexual activity and other related attributes that may influence the risk of cervical cancer. We discuss the results of our survey and what they imply for the possible impact of an HPV immunization plan on the risk of cervical cancer in Japan, and conclude by an emphasis on the need to increase awareness among Japanese female adolescents and to enhance the cervical screening rates among older females who are already sexually active.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2007년도 학술발표회 논문집
• /
• pp.1263-1267
• /
• 2007

A more complete two-dimensional vertical numerical model has been developed to describe the saltwater intrusion in an estuary. The model is based on the previous studies in order to obtain a better accuracy. The non-linear terms of the governing equations are analyzed and the $\sigma$-coordinate system is employed in the vertical direction with full transformation which is recently issued in several studies because numerical errors can be generated during the coordinate transformation of the diffusion term. The advection terms of the governing equations are discretized by an upwind scheme in second-order of accuracy. By employing an explicit scheme for the longitudinal direction and an implicit scheme for the vertical direction, the numerical model is free from the restriction of temporal step size caused by a relatively small grid ratio. In previous researches, some terms induced from the transformation have been intentionally excluded since they are asked the complicate discretization of the numerical model. However, the lack of these terms introduces significant errors during the numerical simulation of scalar transport problems, such as saltwater intrusion and sediment transport in an estuary. The numerical accuracy attributable to the full transformation is verified by comparing results with a previous model in a simply sloped topography. The numerical model is applied to the Han River estuary. Very reasonable agreements for salinity intrusion are observed.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제31권1호
• /
• pp.39-45
• /
• 2005

Stem cell therapy using mesenchymal stem cells(MSCs) transplantation have been paid attention because of their powerful proliferation and pluripotent differentiating ability. Although umbilical cord blood (UCB) is well known to be a rich source of hematopoietic stem cells with practical and ethical advantages, the presence of mesenchymal stem cells (MSCs) in UCB has been controversial and it remains to be validated. In this study, we examine the presence of MSCs in UCB harvests and the prevalence of them is compared to that of endothelial progenitor cells. For this, CD34+ and CD34- cells were isolated and cultured under the endothelial cell growth medium and mesenchymal stem cell growth medium respectively. The present study showed that ESC-like cells could be isolated and expanded from preterm UCBs but were not acquired efficiently from full-terms. They expressed CD14-, CD34-, CD45-, CD29+, CD44+, CD105+ cell surface marker and could differentiate into adipogenic and osteogenic lineages. Our results suggest that MSCs are fewer in full-term UCB compared to endothelial progenitor cells.

• Journal of electromagnetic engineering and science
• /
• 제10권4호
• /
• pp.282-289
• /
• 2010

A simplified, practical vector network analyzer (VNA) that uses mature radio-over-fiber technology has been designed and demonstrated. The measurement concept allows the full S-parameters of a microwave device (or antenna) to be obtained while minimizing the detrimental effects of electrical cables, which are replaced with a photonic link. A variety of high-frequency light modulation schemes with frequency sweeping capabilities are presented to realize a one-path (single, forward), frequency-multiplied optical link for VNA applications. Using the photonic one-path link, full two-port S-parameters have been extracted based on five-term error modeling, which has half the error terms compared with the standard duplex configuration. The S-parameters of a microwave filter and antenna measured using frequency-multiplied optical links are found to be in good agreement with those obtained using a conventional VNA.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
• /
• pp.1487-1506
• /
• 2009

A long-term field experiment of the selected stabilization methods(Cover system, full range and upper range treatment) was conducted to reduce the heavy metal mobility in farmland soil which was contaminated by heavy metals around abandoned mine site. Field experiments were established on the contaminated farmland with the wooden plate and filled with treated soil, which was mixed with lime stone and steel reforming slag except on control plot. Soil samples were collected and analyzed during the experiment period(about 4 months) after the installation of the plots. Field demonstration experiments results showed that the cover system and the full range treatment of the selected stabilization methods applied to the application ratio of lime stone 5% and steel refining slag 2% were effective for immobilizing heavy metal components in contaminated farmland soil.

• 한국정밀공학회지
• /
• 제20권10호
• /
• pp.169-176
• /
• 2003

Genetic algorithm (GA), which has a powerful searching ability and is comparatively easy to use and also to apply, is in the spotlight in the field of the optimization for mechanical systems these days. However, it also contains some problems of slow convergence and low efficiency caused by a huge amount of repetitive computation. To improve the processing efficiency of repetitive computation, some papers have proposed paralleled GA these days. There are some cases that mention the use of gray code or suggest using gray code partially in GA to raise its slow convergence. Gray code is an encoding of numbers so that adjacent numbers have a single digit differing by 1. A binary gray code with n digits corresponds to a hamiltonian path on an n-dimensional hypercube (including direction reversals). The term gray code is open used to refer to a reflected code, or more specifically still, the binary reflected gray code. However, according to proposed reports, gray code GA has lower convergence about 10-20% comparing with binary code GA without presenting any results. This study proposes new Full gray code GA (FGGA) applying a gray code throughout all basic operation fields of GA, which has a good data processing ability to improve the slow convergence of binary code GA.

• 한국물환경학회지
• /
• 제22권3호
• /
• pp.540-545
• /
• 2006

The anaerobic digester supernatant (ADS) with high $NH_4-N$ concentration often results in a $NH_4-N$ overloading to the mainstream process of municipal wastewater treatment plant (MWTP). The nitrogen removal from the ADS is therefore important in order to achieve a stable mainstream process performance as well as to prevent $NH_4-N$ overloading due to ADS. Recently because of several advantages compared to the full nitrification, many works have shown interests in controlling the build-up of $NO_2-N$ in nitritation processes. The application of nitritation could save the aeration power compared to the full nitrification processes. In addition, the denitrification of $NO_2-N$ could reduce organic carbon requirements compared to the $NO_3-N$ denitrification. The purpose of this research was to find out the characteristics of the ADS nitritation and $NO_2-N$ accumulating factors from the laboratory reactor study. As a result based on the long-term laboratory experiment, it can be concluded that the degree of nitritation was closely related with the availability of alkalinity, free ammonia (FA), solid retention time (SRT) and solid concentration in the nitritation reactor.