프리캐스트 계단을 적용한 효율적인 RC 코어의 연속화 시공방법

김욱종,김록배,이도범 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2

The past manpower-dependent method in the constructional industry has raised the problem of high cos - low efficiency. Especially construction of staircase by using conventional form work and concrete placement deteriorates the quality of reinforced concrete, requires many manpower and has many difficulties of work. This study introduces COSEC system(RC _Co_re _Se_quential _C_onstruction Method by Using PC stairs) to reduce the manpower and the construction time and improve quality of structure. This is the new epoch method of installing PC stair elements after the construction of core wall contrary to the existing method of installing PC stair elements before the construction of core wall or at the same time. After reinforced concrete core wall is constructed by the system form in advance, PC landings and stairs are took in and set up between core walls standing right opposite. PC landings are connected by pinned connection with the core wall and PC stairs are simply put on PC landings on both sides. This system makes installation of PC stair elements very easy and improves the quality of stairs and core wall. This study shows the effect of practical application to construction of the building in the field.

철근공사 공장가공 합리화 방안

김동진,김욱종 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1

In domestic construction industry, re-bar work is one of the conventional works that have low productivity and are done by outdated method that is mainly independent on just manpower. And in urban area construction project, the basement covers all of the site, so there is no enough space for stocking and manufacturing re-bar. Nowadays re-bar factory manufacturing is widely spread for coping with this actual problem and developing the outdated re-bar work. But there is little development of re-bar factory manufacturing from its beginning and the dissonance is growing in the job-site using re-bar factory manufacturing. So in this study, we analysed the status of re-bar factory manufacturing and suggested the application method of re-bar factory manufacturing for more practical use. The results of this study are as follows. For successful adaption of re-bar factory manufacturing (1) the partnering of the participants is very important. So in the time of making contract, the method for improving partnership must be considered. And (2) for lessening the re-bar loss in factory manufacturing, it is considered using the Coil re-bar. Finally (3) for making the work process between job-site and factory more streamlined, it is needed making the standard of bar-list shape ID.

구조용 용접철망 실용화 방안 연구

김동진,김욱종 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1

The purpose of this study is to develop application method of structural welded wire fabric(WWF) for practical use in domestic construction industry. One of the main problems of adapting WWF for building construction is the various types of fabric, so the productivity in the factory and in construction field is decreased. The result of this study are as follows. The shape of welded wire fabric was proposed for application in slab and wall(especially the shape of WWF for slab should be one direction reinforcement type). And economical advantage of WWF was analyzed. WWF could be adapted 80.4% cost of SD400.

압연용 ROLL의 열처리를 위한 ROLL내의 열전단 해석

金煜中,尹英煥 國立 昌原大學校 産業技術硏究所 1987 産技硏論文集 Vol.1 No.-

In order to provide the technical guidance for heat treatment process of a back-up roll which is a rolling part of a press for hot iron, unsteady solutions of temperature distributions, in which thermodynamic properties of specific heat, Cp and thermal conductivity, K are a function of temperature, are solved by finite-difference numerical method. First, unsteady solutions to heat conduction equation with the known surface temperature in a infinite solid bar are investigated to obtain proper thermodynamic properties and the surface heating rate of the roll. These solutions are also compared with the calculated and experimental data reported by kobe iron company. Second, the unsteady 2-dimensional solutions with radiative and convective boundary conditions in a real roll with irregular shapes are obtained, where the numerical method of the Implicit-Alterating-Direction is used. From these calculation, the following results are obtained. 1) The heating area near the surface of the roll, which is a important place for the heat treatment, does not much depend on variation of thermodynamic properties of the roll. 2) A high or low limitation of the surface heating rate is considered. 3) The thermal radiation analysis with the weighted sum of gray gases model is effective to predict the gas temperature in the furnace. 4) The even insulations on both side of a real roll are required to obtain a uniform heating temperature contour near the surface.

緯度와 地形에 따른 溫帶中部 溪谷植生의 種多樣性 및 群集構造에 關한 硏究

尹相旭,辛壽哲,郭東勳,金昌浩 동국대학교 농림과학연구소 1994 農林科學 論文集 Vol.18 No.-

This study was Carried out to analyse species composition, species diversity and structure and variation trends of vegetation, of Mt. Odae, Mt. Sobaek, and Mt. Juwang following various latitudes and topographies which were in middle temperate zone in Korea. Obtained results are as follows : 1. As a result of the simple discriminant analysis, soil texture Showed the highest high percent contribution of each environmental factor to the discriminant of Studred area. And Mt. Odae showed high content of sand while Mt. Juwang Showed silt. 2. Mean stem density showed highest value in Mt. Juwang and mean D. B. H. was Mt. Odae, and on phisiographic locations showd high values of stem density and mean D. B. H in slow slope area, nothern aspect area, and high elevation area, in order. 3. Species that showed the highest importance value in each canopy-subtree-shrub layer in study area were Quercus mongolica-Acer pseudo-sieboldianum-Lindera obtusiloba were in Mt. Odae, Betula platyphylla var. japonica-Styrax obassia-Deutzia parviflora were in Mt. Sobaek, and Pinus densiflora-Acer pseudo-sieboldianum-Lindera obrusiloba were in Mt. Juwang. 4. Species that showed the highest importance value in each canopy-subtree-shrub layer on the physiographic location were Quercus mongolica-Acer pseudo-sieboldianum-Lindera obtusiloba in high elevation and southern aspect, Carpinus laxiflora-Acer pseudo-sieboldianum-Lindera obtusiloba in high elevation and southern aspect, Carpinus laxiflora-Acer pseudo-sieboldianum-Lindera obtusiloba in nothern slope, Carpinus laxiflora-Styrax obassia-Lindera obtusiloba in low elevation, and Betula platyphylla var. japonica-Styrax obassia-Deutzia parviflora in high elevation. 5. According to decrease of latitudes with going down from Mt. Odae to Mt. Juwang, the more Number of species and individuals were increased, and the deversity index was the highest value in Mt. Sobaek, the evenness was in southern aspect, and the dominance was in high elevation. 6. As a result of Cluster analysis, the study area were divided into 4 groups, Carpinus laxiflora community, Styurax obassia community, Deutzia parviflora community, and Quercus mongolica community. 7. As a result of COA analysis, communities of the study area were divided into Betula platyphylla var. japonica community, Deutzia parviflora community, Quercus mongolica-Acer pseudo-sieboldianum community, and species were divided into 4 groups as the major, the disturbed, the waterside, and the fertile. 8. As results of the simple discriminant analysis and the linear regression, sand and silt content, slope aspect, total nitrogen content, and elevation among environmental factors had high percent contribution to classification and ordination of vegetation communities of the study area. 9. Major tree species had the unstable layer structure due to lower importance values of canopies and subtrees than those of shrubs, and Pinus laxiflora and Betula platyphylla var. japonica were on the decline phase due to very low dominance and absence of next generation. while, Styrax obassia and Acer pseudo-sieboldianum were sustanable layer structure as being distributed on all the crown layer.

Visible-Light-Driven Photoproduction of Hydrogen Using Rhodium Catalysts and Platinum Nanoparticles with Formate

Kim, Soojin,Lee, Ga Ye,Baeg, Jin-Ook,Kim, Youngmee,Kim, Sung-Jin,Kim, Jinheung American Chemical Society 2014 JOURNAL OF PHYSICAL CHEMISTRY C - Vol.118 No.45

<P>Photochemical hydrogen production is carried out using molecular Rh complexes and sodium formate in the presence of platinum nanoparticles (PtNPs) in aqueous buffer solution. Visible-light-driven photocatalytic reactions for hydrogen production with and without nicotinamide adenine dinucleotide (NAD<SUP>+</SUP>) follow two different pathways. Complex [Cp*Rh(bpy)(OH<SUB>2</SUB>)]<SUP>2+</SUP> selectively reduces NAD<SUP>+</SUP> to generate NADH using formate as a proton and electron donor and the chemically generated NADH is sequentially used by PtNPs upon photoactivation of eosin Y to produce hydrogen. However, hydrogen is also produced in photoreactions of the Rh catalyst and PtNPs with formate in the absence of NAD<SUP>+</SUP> and eosin Y. The second pathway for hydrogen production was performed under the conditions without NAD<SUP>+</SUP> and eosin Y and derived from a direct electron transfer from <I>in situ</I> generated rhodium(III)-hydride species to photoexcited PtNPs. The direct electron transfer from the rhodium-hydride species to visible-light-driven PtNPs was first observed in this study. These two pathways for hydrogen production showed different rate-limiting steps based on a Hammett plot using Rh catalysts containing electron-donating and electron-withdrawing groups. Kinetic isotope effects as well as Hammett plot supported the rate-limiting step of the NADH generation for the first pathway of hydrogen production and the Rh–H formation for the second pathway.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jpccck/2014/jpccck.2014.118.issue-45/jp504876w/production/images/medium/jp-2014-04876w_0012.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jp504876w'>ACS Electronic Supporting Info</A></P>

Diagnostic Mutational Analysis of MECP2 in Korean patients with Rett syndrome

Kim, In-Joo,Kim, Yeon-Joo,Son, Byeong-Hee,Nam, Sang-Ook,Kang, Hoon-Chul,Kim, Heung-Dong,Choi, Ook-Hwan,Yoo, Mi-Ae,Kim, Cheol-Min 대한유전성대사질환학회 2005 대한유전성대사질환학회지 Vol.5 No.1

Purpose: Rett syndrome (RTT) is an X-linked dominant neurodevelopmental disorder affecting 1 per 10,000~15,000 female births worldwide. The disease-causing gene has been identified as MECP2 (methyl-CpG-binding protein). In this study, we carried out diagnostic mutational analysis of MECP2 gene in RTT patients. Methods: We analyzed four exons and putative promoter of MECP2 gene from the peripheral blood of 43 Korean patients with RTT by PCR-RFLP and direct sequencing. Results: Mutations were detected in MECP2 gene about 60.5% of patients. The mutations consisted of 14 different types including 9 missense mutations, 4 nonsense mutations and 1 frameshift mutation. Of these, three mutations (G161E, T311M, P385fsX409) were newly identified and these were determined as disease-causing mutations by PCR-RFLP and direct sequencing analysis. Most of the mutations were located within MBD (42.3%) and TRD (50%). T158M, R270X, and R306C mutations were identified with high frequency. An intronic SNP (IVS3+23C>G) was newly identified in only three of the patients. It may be a disease-related and Korea-specific SNP with RTT. The L100V and A201V have been reported to be unclassified variant and SNP. However, these mutations were not found in more than 100 normal Korean control samples. These base substitutions seem to be the disease-causing mutations in Korean RTT contrary to previous studies. Conclusion: Disease-causing mutations and polymorphisms would be very important for diagnosing of RTT in Korean. The experimental procedure used in this study might be considered for molecular biologic diagnosis used in clinical field.

Risk factors of stoma re-creation after closure of diverting ileostomy in patients with rectal cancer who underwent low anterior resection or intersphincteric resection with loop ileostomy

Ook Song,Kyung Hwan Kim,Soo Young Lee,Chang Hyun Kim,Young Jin Kim,Hyeong Rok Kim 대한외과학회 2018 Annals of Surgical Treatment and Research(ASRT) Vol.94 No.4

Purpose: The aim of this study was to identify the risk factors of stoma re-creation after closure of diverting ileostomy in patients with rectal cancer who underwent low anterior resection (LAR) or intersphincteric resection (ISR) with loop ileostomy. Methods: We retrospectively reviewed 520 consecutive patients with rectal cancer who underwent LAR or ISR with loop ileostomy from January 2005 to December 2014 at Chonnam National University Hwasun Hospital. Risk factors for stoma re-creation after ileostomy closure were evaluated. Results: Among 520 patients with rectal cancer who underwent LAR or ISR with loop ileostomy, 458 patients underwent stoma closure. Among these patients, 45 (9.8%) underwent stoma re-creation. The median period between primary surgery and stoma closure was 5.5 months (range, 0.5–78.3 months), and the median period between closure and recreation was 6.8 months (range, 0–71.5 months). Stoma re-creation was performed because of anastomosis-related complications (26, 57.8%), local recurrence (15, 33.3%), and anal sphincter dysfunction (3, 6.7%). Multivariate analysis showed that independent risk factors for stoma re-creation were anastomotic leakage (odds ratio [OR], 4.258; 95% confidence interval [CI], 1.814–9.993), postoperative radiotherapy (OR, 3.947; 95% CI, 1.624–9.594), and ISR (OR, 3.293; 95% CI, 1.462–7.417). Conclusion: Anastomotic leakage, postoperative radiotherapy, and ISR were independent risk factors for stoma re-creation after closure of ileostomy in patients with rectal cancer.

A Digital Self Compensation Circuit for High Speed D / A Converters

Ook Kim,Jung Wook Yang,Suk Ki Kim,Won Chan Kim 대한전자공학회 1994 대한전자공학회 학술대회 Vol.1994 No.1

A Three-Channel Digital to Analog Converter Using BiCMOS Circuit Technology

Kim, Ook,Kim, Gyu Dong,Park, Sung Jun,Song, Mun Sik,Kim, Won Chan 대한전자공학회 1991 ICVC : International Conference on VLSI and CAD Vol.2 No.1

A monolithic 3-channel BiCMOS DAC (Digital to Analog Converter) based on the R-2R ladder and segmentation is presented. To reduce power consumption, mixed bipolar and CMOS circuits were used. In the digital part of this DAC, CMOS circuits were used for power reduction. To drive bipolar current switches, a new BiCMOS level translator was invented for minimization of glitch. A voltage reference was designed and a temperature and supply independent biasing was realized. Ta analyze the effect of the voltage sensitivity of resistor, a simple model of the ladder resistor resistance was made. The 3-channel 8-hit DAC was fabricated by 1.5㎛ BiCMOS process, and operates up to 80MHz and shows 7.5 bit resolution at 10MHz without trimming. Its linearity error is 0.33 LSB, and the differential nan-linearity is 0.12 LSB. This chip consumes abaut 200mW. The total chip size is 2.21×3.27 ㎟.