• Journal of the Korea Concrete Institute
• /
• v.20 no.6
• /
• pp.833-840
• /
• 2008

The time and cost can be reduced when applying partial precast concrete to the stair system in comparison to the cast-in-place or precast method. Because the performance of staircase which is used for evacuation can be largely different from connection types of precast concrete member, we tried to know structural behavior and performance evaluation according to each type of stair joints by experimental study. In the cast-in-place rigid joint, much reinforcement is needed in the end portion because much stress is concentrated in the middle portion. Also, in the pin joint which is used in the connection point, the maximum stress occurs in the middle point, so not only the amount of re-bar is increased but also the serviceability is largely decreased. The bolt type of semi-rigid joints proposed in this study had been increased strength and serviceability which is similar to the rigid joints. Also, its ductility was shown about 0.7 times in comparison to the rigid type and was about 2.8 times for the pin joint type. According to the classification of joint in Eurocode, it can be considered that it is one of the semi-rigid joints which are in the semi-rigid-full strength, and the structural behavior can be expected by using a model which applied to stiffness value decreased by 40 percent.

• Journal of the Korean School Mathematics Society
• /
• v.20 no.1
• /
• pp.57-76
• /
• 2017

Since the 1990s, Korea has been developing various policies and materials for the improvement of basic learning abilities. In this study, the cases of policies for underachievers in Korea and the US were compared and analyzed the programs for mathematics underachievers in elementary school with Chuncheon office of education and Seattle public schools. All of them started from the point of relief of underachievers, but they differed in the process of operating them specifically. This study suggests the followings. First, active utilization of vacation programs to solve problems such as low-income meal service, prevention of stigma effects, securing teacher's instruction time, teacher-instructor cooperation. Second, the necessity of detailed activity-centered textbooks that underachievers can explore with interest in mathematics learning and easy to use by teachers. Third, specific cooperation for inducing interest of their own children's learning and forming close ties between parents and teachers. Fourth, program analysis by a professional evaluation group to improve the quality of underachiever program.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.04a
• /
• pp.301-304
• /
• 2008

The stair joints constructed with prefabricated system are general method doing structure design at hinge. If you regarded joints to come in contact with a flight of stairs and a slope of stairs as hinge, the moment performance of joints is not in the least moment, so as the bending moment of the stair case is increased, the reinforcement increase. Also the use is decreased because increasing the joint damage of the vibration & fatigue load. No less the reason constructed with pin the stair joints because the construction efficiency of field work is useable. Recently, they are considering the construction efficiency, while the semi-rigid detail for bending performance of joints is proposed, but for now they don't reflect the detail. Therefore, we proposed that reflecting the method at design semi-rigid joints. We compared the moment performance with the stair joints designed at the rigid joints, semi-rigid joints and pin joints. The nonlinear behavior of staircase core statically indeterminate structure. The result of research is that a bending stiffness modulus bring to reflect the semi-rigid performance, the performance of the semi-rigid joint is better than pin joints, and that is judged the system better seismic and vibration performance because have excellent ductility more than rigid joint.

• The Korean Journal of Physiology
• /
• v.14 no.2
• /
• pp.7-16
• /
• 1980

The effects of various inotropic interventions on the shape of the steady state length tension relation and the length-dependent activation process in cardiac muscle were studied. The influence of inotropic interventions upon the action potential was also observed. The range of varying muscle length was from the optimal length$(l_{max})$, where the active tension production is maximal, to 0.85 $l_{max}$. Changes in stimulus frequency or in external bathing Ca concentration constituted the inotropic interventions in this experiment. The papillary muscles were isolated from the rabbit right ventricles and perfused with $HCO-_3\;-buffered$ normal Tyrode solution which was aerated with $3%\;CO_2-97%\;O_2$ mixed gas and kept at $35^{\circ}C$. Resting Passive tension at $l_{max}$ was approximately 30% of the total tension and appeared from the muscle length of 0.90 $l_{max}$. The effect of stimulus frequency on the steady state level of developed tension was: As the stimulus frequency was increased from 0.1 to 0.5 Hz, there was little change in developed tension. As the frequency was increased further, to a value of about 3 Hz, tension increased steeply. Further increase of the frequency to 5 Hz had little additional effect on the developed tension. The length-tension curves for isometric peak tension became more steeper with the degree of potentiation by inotropic interventions. The relative steepness of the normalized length-tension curves where tension production was expressed as a percentage of maximal tension developed at $l_{max}$, varied inversely with the level of inotropic state and these curves were not superimposable one another. Thus at the stimulus frequency of 2 Hz or at the external Ca concentration of 8 mM, the relative decline in the developed tension for a given change in muscle length was considerably less than the decline observed at the frequency of 0.5 Hz or at the concentration of 2 mM Ca. Action potential duration was prolonged significantly as the frequency increased from 0.2 to 2 Hz, and this change in action potential duration was not observable on the changes in muscle length. There was a tendency of the hyperpolarization of membrane potential when the muscle length was shortened from $l_{max}$ to 0.95 $l_{max}$. These results support the hypothesis that there is a length-dependence of the activation process.

• Journal of Conservation Science
• /
• v.34 no.1
• /
• pp.11-21
• /
• 2018

The result of the study on the origin and preservation status of the 'Gongju Junghakdong old missionary house', the Registered Cultural Property No. 233, reveals that the building was approved on October 23, 1921, and missionary Alice H. Sharp was living in the building until her retirement from her missionary life of 39 years in Korea in 1939. In order to review internal and external preservation status of the building, condition of wood material, the composition of the window, the damage of the wall, and the leaning of the building were examined. In particular, in the case of window facilities, it is necessary to restore it to the original upper and lower sliding window. As a result of investigation of the preservation status of the external facilities, it is necessary to restore the original shape of the staircase and a deck of the building on south western side and the well. In addition, the results of the non-destructive diagnosis of the ground revealed that the building was built on uneven surface layer of 2-5 m thickness and the boundary between the surface layer and the upper part of the weathered rock is inclined following geomorphology. This phenomenon shows that when the water content of the ground increases in the rainy season, the bearing capacity of the ground is lowered, and there is a possibility of uneven subsidence. Especially, landslides may occur in case of heavy rain. Therefore, it is desirable to install a masonry facility at the southwest boundary of the site, and it is recommended to install a drainage facility to ensure rapid drainage.

• The Journal of the Convergence on Culture Technology
• /
• v.7 no.4
• /
• pp.869-878
• /
• 2021

This study is a study on 11-story apartments that increase the event of fires in old apartments where building-related laws and regulations are not retroactively applied. As a result of analyzing the risk of installing fire doors in Improvement Scenario 2-4, assuming that fire doors are installed as basic scenario 1 in the existing situation where fire doors are not installed at the entrance of direct stairs. In basic scenario 1, the visible distance to the entrance of the direct staircase due to the spread of smoke was 260 seconds. Improvement scenarios 3 to 4 with fire doors installed open 300 seconds after the fire was recognized, and when the fire doors were installed at the entrance of the direct stairs, the visibility to the entrance of the statistics team was less than 600 seconds. In this case, the visibility was 600 seconds at the time of installation of the fire door, and scenarios 3 to 4 increased 56.6% compared to scenario 1, lowering the risk of evacuation by more than 50%. In order to eliminate the risk of non-installation of direct statistical groups that increase the risk of smoke spread, building-related laws such as the Fire Fighting Act shall be retroactively applied when installing a direct stairway entrance or balcony folding evacuation system. The improvement caused by the installation of fire doors has numerically proven the necessity of fire doors during evacuation, and the importance of maintaining fire doors can be grasped.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
• /
• v.8 no.6
• /
• pp.957-966
• /
• 2018

Recently, the demand for remote patient monitoring based on IoT has been increased due to aging population and an increase in single-person household. A non-contact biological signal measurement system using multiple IR-UWB radars for remote patient monitoring is proposed in this paper. To reduce error signals, a multilayer Subtraction algorithm is applied because when the background subtraction algorithm was applied to the biological signal processing, errors occurred such as voltage noise and staircase phenomenon. Therefore, a multilayer background subtraction algorithm is applied to reduce error occurrence. The multilayer background subtraction algorithm extracts the signal by calculating the amount of change between the previous clutter and the current clutter. In this study, the SVD algorithm is used. We applied the improved multilayer background subtraction algorithm to biological signal measurement and computed the respiration rate through Fast Fourier Transform (FFT). To verify the proposed system using IR-UWB radars and multilayer background subtraction algorithm, the respiration rate was measured. The validity of this study was verified by obtaining a precision of 97.36% as a result of a control experiment with Neulog's attachment type breathing apparatus. The implemented algorithm improves the inconvenience of the existing contact wearable method.

• The Journal of the Petrological Society of Korea
• /
• v.9 no.4
• /
• pp.211-237
• /
• 2000

Major element zoning has been analyzed in garnet porphroblasts obtained from the Grt-St and Ky-Grt-St grade assemblages in Zones I on the northern flank of the Pelham Dome, north central Massachusetts. These porphyroblasts grew during multiple phases of deformation and meta-morphism revealed by the inclusion trail geometry plus the chemical zoning patterns within garnet porphyroblasts. Unusual zoning patterns, including zoning reversals and gradient changes in XMn, zlgzag patterns in Fe/(Fe +Mg) and staircase-shaped patterns in XCa, are coincident with textural truncations and other changes in microstructure within the garnet porphrublasts. Chemical variations in plagioclase, biotite, muscovite and staurolite combined with inclusion trail geometry and petrography reveal that the garnet zoning patterns are modified by combinations of the following. (1) Uni-and divariant reactions involving garnet consumption(Grt+ Chl+Ms=St+Bt+Qtz + $H_2$O) and production(St+Ms + Qtz= Bt+ Grt +A1$_2$$SiO_{5}$ + $H_2$O). (2) Deformation induced episudic ionit dissolution, preferential diffusion and re-distribution during foliation development. (3) P-T changes during growth of the porphyroblasts. The P-T paths combined with petrographic and inclusion trail morphology observations consist of two pattens; (1) heating/compression during NW-SE shortening; and (2) decompression with cooling during NNW-SSE shortening. Based on temperature-time(T-t) geochronological data and late-Paleozoic tectonic model, Alleghanian metamorphism, which is the result of heterogeneous shearing concentrated along the boundary between the Abalone Terrane(Pelham dome) and cover rocks(Bronson Hill Terrane), has produced Ky-St-Ms mineral assemblage during Pennsylvanian(290-300 Ma) in Shutesbury area. However, temperature of alleghanian metamorphism was not high enough to form garnet and staurolite in the Northfiled syncline area. Alleghanian metamorphism has affected only the matrix due to heterogeneous shearing in the study area.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.39 no.4
• /
• pp.10-23
• /
• 2021

During the Japanese colonial period, the palaces of Joseon were damaged in many parts. Changgyeonggung Palace is the most demolished palace with the establishment of a zoo, botanical garden, and museum. During the Japanese colonial period, the palaces of Joseon were damaged in many parts. This study examined the construction process of Jangseogak(Yi Royal-Family Museum), located right next to the Jagyeongjeon site, which was considered the most important space in the Changgyeonggung residential area of royal family zone, through historical materials and field research. Built in 1911, Jangseogak is located at a location overlooking the entire Changgyeonggung Palace and overlooking the Gyeongseong Shrine of Namsan in the distance. Changes in the surrounding space during the construction of Jangseogak can be summarized as follows. First, in the early 1910s, the topography of the garden behind Jagyeongjeon and part of the Janggo were damaged to create the site of Jangseogak. The front yard was built in the front of Jangseogak, and a stone pillar was installed, and a staircase was installed to the south. In the process, the original stone system at the rear of Yanghwadang was destroyed, and it is presumed that Jeong Iljae and other buildings were demolished. Second, in the 1920s, many pavilions were demolished and the zoo and botanical gardens and museums were completed through leveling. After the Jangseogak was completed, the circulation of the Naejeon and surrounding areas was also changed. Cherry trees and peonies were planted in the flower garden around the front yard of Jangseogak and the stairs, and a Japanese-style garden was created between Yanghwadang and Jibbokheon. Third, in the 1930s, the circulation around Jangseogak was completed in its present form, and the museum, Jangseogak, Zoological and Botanical Gardens, and Changgyeonggung, which became a cherry tree garden, were transformed into a Japanese-style cultural park. After that, the surrounding space did not change much until it was demolished. The restoration of the present palace is a long-term, national project of the Cultural Heritage Administration. The results of this study will provide important data for the restoration plan of Changgyeonggung Palace in the future, and it is expected that it will provide additional information to related researchers in the future.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.39 no.4
• /
• pp.24-37
• /
• 2021

This study was conducted to newly examine the original landscape of Buyongjeong(芙蓉亭) and Juhamnu(宙合樓) areas in Changdeokgung Palace(昌德宮), focusing on the modern period including the Korean Empire, and to derive useful research results for restoration and maintenance in the future. The study results can be summarized as follows. First, the artificial island in Buyongji(芙蓉池) was originally made up of a straight layer using well-trimmed processed stone. However, during the maintenance work in the 1960s and 1970s, the artificial island in Buyongji was transformed into a mixture of natural and processed stones. The handrail installed on the upper part of the artificial island in Buyongji is a unique facility that is hard to find similar cases. The handrail existed even during the Korean Empire, but was completely destroyed during the Japanese colonial period. Second, Chwibyeong(翠屛), which is currently located on the left and right of Eosumun(魚水門), is the result of a reproduction based on Northern bamboo in 2008. Although there is a view that sees the plant material of Eosumun Chwibyeong as Rigid-branch yew, the specific species is still vague. Looking at the related data and circumstances from various angles, at least in the modern era, it is highly probable that the Eosumun Chwibyeong was made of Chinese juniper like Donggwanwangmyo Shrine(東關王廟) and Guncheongung(乾淸宮) in Gyeongbokgung Palace(景福宮). Third, the backyard of Juhamnu was a space with no dense trees on top of a stone staircase-shaped structure. The stone stairway in the backyard of Juhamnu was maintained in a relatively open form, and it also functioned as a space to pass through the surrounding buildings. However, as large-scale planting work was carried out in the late 1980s, the backyard of Juhamnu was maintained in the same shape as a Terraced Flower Bed, and it was transformed into a closed space where many flowering plants were planted. Fourth, Yeonghwadang Namhaenggak(暎花堂 南行閣), which had a library function like Gyujanggak(奎章閣) and Gaeyuwa(皆有窩), was destroyed in the late 1900s and was difficult to understand in its original form. Based on modern photographs and sketch materials, this study confirmed the arrangement axis of Yeonghwadang Namhaenggak, and confirmed the shape and design features of the building. In addition, an estimated restoration map referring to 「Donggwoldo(東闕圖)」 and 「Donggwoldohyung(東闕圓形)」 was presented for the construction of basic data.