• Steel and Composite Structures
• /
• v.36 no.4
• /
• pp.427-446
• /
• 2020

This paper carries out the progressive collapse analysis of stainless steel composite beam-to-column joint sub-models and moment-resisting frames under column removal scenarios. The static flexural response of composite joint sub-models with damaged columns was initially explored via finite element methods, which was validated by independent experimental results and discussed in terms of moment-rotation relationships, plastic hinge behaviour and catenary actions. Simplified finite element methods were then proposed and applied to the frame analysis which aimed to elaborate the progressive collapse response at the frame level. Nonlinear static and dynamic analysis were employed to evaluate the dynamic increase factor (DIF) for stainless steel composite frames. The results suggest that the catenary action effect plays an important role in preventing the damaged structure from dramatic collapse. The beam-to-column joints could be critical components that influence the capacity of composite frames and dominate the determination of dynamic increase factor. The current design guidance is non-conservative to provide proper DIF for stainless steel composite frames, and thus new DIF curves are expected to be proposed.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.1
• /
• pp.683-690
• /
• 2015

Two basic FFT(Fast Fourier Transform) algorithms are the DIT(Decimation-In-Time) and the DIF (Decimation-In-Frequency). In spite of the advantage of the DIT algorithm is to generate a sequential output, various structures have not been made. In this paper, a new DIT Radix-4 FFT butterfly structure are proposed and implemented using Verilog coding. Through synthesis, it is shown that the 64-point FFT is implemented by 6.78 million gates. Since the proposed FFT structure has the advantage of a sequential output, it can be used in OFDM communication SoC(System on a Chip) which need a high speed FFT output.

• Physical Therapy Korea
• /
• v.22 no.3
• /
• pp.61-70
• /
• 2015

To develop an effective and efficient measurement system for tracking changes of functional status across two measures, it is essential to integrate information and communicate scores across two measures. The lack of communication between two measures leads to score incompatibility. A potential solution would be the development of a crosswalk table between those measures. Prior to creating a crosswalk table, selecting common items between two measures is critical. By using the Oswestry low back pain disability questionnaire (Oswestry) and a short form measuring disability resulting from low back pain, item level statistics as well as differential item functioning (DIF) using the Rasch measurement were investigated. Eighty-two participants with known group validity were recruited. Based on the application of the Rasch measurement model, item difficulties across the two measures were logically and hierarchically ordered. Ceiling effects for both measures were detected, which were not be able to be effectively measured with the two measures. The DIF analysis across the two measures confirmed that five paired items were found to have DIF and five common items were selected for common items. Although five paired items function differently across the Oswestry and the short form, all items of both measures were well targeted study participants. The common items selected by the Rasch measurement model may be effective when creating a crosswalk table between the Oswestry and the short form.

• Journal of Oral Medicine and Pain
• /
• v.41 no.1
• /
• pp.16-20
• /
• 2016

Purpose: Oral lichen planus (OLP) is relatively common mucosal disease in clinical dentistry. OLP is intractable and regarded having malignant potential. Until now, there is some debate on how far OLP can be malignant, and which characteristics can be a risk factor for malignant transformation. Clinician need to know some differences between OLP and lesions similar to OLP to manage properly and suppose prognosis correctly. Therefore, the aim of this study was to divide clinical OLP into two groups and to compare the results of direct immunofluorescence (DIF) between two groups. Methods: This study was conducted on outpatients who visited at the department of Oral Medicine in Chonbuk National University Hospital from January 2007 to November 2015. Patients with DIF result were retrospectively reviewed. The selected patients were classified 'clinical typical of OLP' (CTO) or 'clinical compatible with OLP' (CCW) by modified World Health Organization diagnostic criteria of OLP and oral lichenoid lesion. Results: DIF were classified by deposition intensity or pattern of anti-human antibody and fibrinogen. The classification of fluorescence pattern in each specimen was graded as positive, possibly positive or negative. Conclusions: Both CTO and CCW had positive and possibly positive pattern. Prevalence of positive pattern was 68.8% in CTO and 52.6% in CCW and that of possibly positive pattern was 9.4% in CTO and 5.3% in CCW. Prevalence of negative was 21.8% in CTO and 42.1% in CCW.

• Journal of Cadastre & Land InformatiX
• /
• v.47 no.1
• /
• pp.277-292
• /
• 2017

The development impact fee (DIF) zoning is a very beneficial public tool to provide the pre-planned urban infrastructures in those areas where significant urban sprawl had already taken place. In order to guarantee its benefit, however, it is required to designate the zone boundaries accurately and consistently. This study, in this context, tries to test the validity of the 50m-grid suggested in the official DIF manual, and to compare an alternative Hot Spot Analysis tool with the existing Spatial Aggregation method in configuring the zone boundaries. The results indicate that, unlike the case of population growth rate, current 50m grid size could not be much adequate in the case of using the development-permit increase rate to configure the primary DIF zones. Also, the optimal grid sizes seem to differ in the cases of Spatial Aggregation and Hot Spot Analysis. Further extended studies, in this regard, seem necessary to check the validity of the existing grid-size criteria as well as the boundary configuration methods.

• Journal of Bio-Environment Control
• /
• v.5 no.1
• /
• pp.1-6
• /
• 1996

For reducing planting distance in greenhouse grown watermelon(Citrullus vulgaris S.) this experiment was carried out to study the effect of DIF on stem elongation and growth. Day temperatures ranged from $25^{\circ}C$ to 35$^{\circ}C$ : night temperatures ranged from $25^{\circ}C$ to 35$^{\circ}C$ at 5$^{\circ}C$ interval. Stem elongation, leaf size, dry weight and flowering were influence by day and night temperatures. Stem elongation and length of internode decrease with increasing night temperature at same day temperature. The optimums for number of leaves categories was with day at 35$^{\circ}C$, and flower production was the lowest at $25^{\circ}C$. Total leaf area meter was maximized at 35/30(DT/NT), but for size pet one leave was the largest 25/25(DT/NT). Responses of leaf size per leaves were similar to that of internode length, with maximum day and night at $25^{\circ}C$. Total plant dry weight was the highest 35/30 (DT/NT) and minimum occurring at 25/30(DT/NT). The shoot/root ratios of dry weight Increased with day temperature up to 3$0^{\circ}C$ and were the highest with night at $25^{\circ}C$. Chlorophyll contents decreased with decreasing day and night temperature.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.61 no.2
• /
• pp.131-137
• /
• 2016

This study was conducted to investigate the effects of temperature and shade, which are basic environmental conditions, on growth, yield, inorganic components, and general components of Codonopsis lanceolata, in order to obtain basic data for improving yield capacity. In natural light, in the 15, 20, and $25^{\circ}C$ groups, the plant heights ranged between 218.9 cm and 223.9 cm, and there was no significant difference between groups. However, the leaf size was larger in shade, and the leaf area was significantly larger in the 15 and $30^{\circ}C$ groups. In natural light, root length and diameter were shorter and thinner when the temperature was higher, and growth was highly suppressed at $30^{\circ}C$. With regards to macroelements, the contents of Na, Mg, and P increased as temperature increased, regardless of the plant part; however, no constant tendency was observed in K and Ca according to temperature. The contents of Mg and Ca (from highest to lowest) were in the order leaf>stem>root, whereas the contents of Na, P, and K were in the order stem>leaf>root. Contents of general components varied according to temperature, and were highest at $30^{\circ}C$. While the plant height was increased under the constant $25^{\circ}C$+DIF (Difference between day and night temperature) condition, growth was suppressed in the -DIF group, in which the night temperature was higher than the day temperature, which suggests that a change in night temperature is one of the factors that affects the growth of C. lanceolata. As in the growth of the above-ground parts, fresh weight of the root was high in the constant $25^{\circ}C$ group and +DIF group. Notably, it was more than 2.5 times the fresh weights in the constant $15^{\circ}C$ group, constant $20^{\circ}C$ group, and -15 DIF group.

• Journal of Microbiology and Biotechnology
• /
• v.14 no.2
• /
• pp.367-372
• /
• 2004

Infection of Drosophila melanogaster adults with Pseudomonas aeruginosa (PA14) can kill the flies within 48h. We found that the virulence of PA14 was significantly attenuated when treated with a reducing agent, dithiothreitol (DTT), prior to infection. Infection with DTT-treated PA14 elevated Metchnikowin expression at 22 h post-infection and the virulence of DTT-treated PA14 was not attenuated in Dif and Relish mutants. These results suggest that DTT pre-treatment of PA14 can aggravate certain virulence factors that may be required to paralyze fly immune responses, triggering Metchnikowin expression via Dif and Relish activations.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2007.05a
• /
• pp.570-576
• /
• 2007

수중천퇴가 있는 지형을 통과하며 변형하는 파랑을 실험한 Vincent와 Briggs (1989)의 실험조건을 수치모의하여 파랑과 흐름의 상호작용 효과를 연구하였다. SHORECIRC 흐름모형을 결합한 파랑모형 REF/DIF 1과 SWAN, 그리고 파랑과 흐름을 동시에 수치모의 할 수 있는 FUNWAVE를 이용하여 수중천퇴상을 통과하며 변형하고 또 다시 수중천퇴상에서 발생한 쇄파에 의해 발생된 쇄파류에 의해 변형하는 규칙파를 수치모의하였다. 수중천퇴상에서 쇄파가 발생할 때 잉여파응력의 급격한 변화에 따른 강한 유사제트류가 발생하고, 이 흐름은 수중천퇴후면의 파집중현상을 방해하여 파랑을 천퇴중심축으로부터 바깥쪽으로 굴절시켜, 파고를 상대적으로 감소시키는 역할을 한다. 이러한 역학은 실험결과와 본 연구의 수치모의를 통해 확인할 수 있었고, 이는 파랑쇄파류의 파랑변형에 미치는 역할의 중요성을 확인시켜주는 것이다. 규칙파 모의에 한계가 있는 SWAN과 규칙파 특성상 강하게 나타나는 중복파의 잉여파응력계산에 한계가 있는 REF/DIF 1과 달리 FUNWAVE를 이용한 수치모의는 실험결과와 완벽히 일치하였으며, 수중천퇴 후면에 발생하는 쇄파류와 쇄파류에 의한 쌍 vortex의 발달과정을 잘 보여 주었다.

• Journal of Veterinary Clinics
• /
• v.17 no.2
• /
• pp.420-430
• /
• 2000

These studies were preformed to investigate the freezing conditions to achieve good post-thaw viability of spend and the practical methods of artificial insemination frozen canine semen. Semen were collected from nine male dogs which had been proved to be fertile in the past and the semen were treated for freezing procedure. Post-thaw motility and viability of canine sperm were evaluated to investigate individual tolerance of freezing, difference among freezing extenders, dif-ference among freezing equipments and freezing conditions, difference between fast and slow cooling rate, difference according to different glycerol concentration, effect of seeding on post-thaw viability, difference according to cutting part of straw, difference according to thawing temperatures, and dif-ference according to media added to thawed semen. Thawed semen for insemination were added with equal volnme of canine capacitation medium (CCM) and the volume of semen and the number per insemination were adjusted as 2-3 ml and $20-30 {\times}10^7,$ respectively. The semen were inseminated in vagina using balloon catheter and en17ryos were cellected from 9 to 11 days after the second Al to d determine fertilization.