• 천문학회지
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• 제55권6호
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• pp.195-205
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• 2022

We investigate infrared properties of OGLE4 Mira variables in our Galaxy. For each object, we cross-identify the AllWISE, 2MASS, Gaia, and IRAS counterparts. We present various IR two-color diagrams (2CDs) and period-magnitude and period-color relations for the Mira variables. Generally, the Mira variables with longer periods are brighter in the IR fluxes and redder in the IR colors. In this work, we also revise and update the previous catalog of AGB stars in our Galaxy using the new sample of OGLE4 Mira variables. Now, we present a new catalog of 74,093 (64,609 O-rich and 9,484 C-rich) AGB stars in our Galaxy. A group of 23,314 (19,196 O-rich and 4,118 C-rich) AGB stars are identified based on the IRAS PSC and another group of 50,779 (45,413 O-rich and 5,366 C-rich) AGB stars are identified based on the AllWISE source catalog. For all of the AGB stars, we cross-identify the IRAS, AKARI, MSX, AllWISE, 2MASS, OGLE4, Gaia, and AAVSO counterparts and present various infrared 2CDs. Comparing the observations with the theory, we find that basic theoretical dust shell models can account for the IR observations fairly well for most of the AGB stars.

• Steel and Composite Structures
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• 제45권1호
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• pp.23-38
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• 2022

This paper presents experimental and analytical studies of eccentrically loaded concrete-filled double steel (CFDST) and concrete-filled double skin tube (DCFST) columns having outer stainless steel tube. Eighteen CFDST and DCFST column specimens were manufactured and tested to examine the strength and load-deflection responses. In the study, the main parameters were concrete strength, load eccentricity, cross section and slenderness. The strengths, load-deflection diagrams and failure patterns of the columns were observed. In addition, the tested CFDST and DCFST columns were analyzed to attain the capacity and load versus lateral deflection responses. The obtained theoretical results were compared with the test results. A parametric study was also performed to research the effects of the ratio of eccentricity (e/H_o) slenderness ratio (L/r), H_o/t_o ratio, H_i/t_i ratio and the concrete compressive strength on the behavior of columns. In this work, the obtained results indicated that the ductility and capacity of columns were affected by cross section, concrete strength, steel strength, loading eccentricity and slenderness.

• Asia pacific journal of information systems
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• 제31권1호
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• pp.1-16
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• 2021

Cyberbullying has become a social problem as malicious text messages and online comments among teenagers have increased in the late 2000s. Some serious reporting has attempted to impress on us the need to pay more attention to reducing malicious online content as a typical type of cyberbullying. Meanwhile, despite environmental changes that have made it easier to report perpetrators of such messages, it is often the case that the crime occurs in a public place and is tolerated. However, there is a growing tendency for people to exhibit the bystander effect, the problem of personal indifference to witnessing or knowing about crimes, but individuals do not offer any means of help to a victim when other people are present. This effect is rampant in the case of cybercrimes. This study aims to extract the motivations behind posting malicious comments through in-depth interviews and to suggest recommendations for relative issues by demonstrating how the bystander effect can be reduced using causal relationship diagrams of the system dynamics methodology. Hopefully, this work will contribute to a better understanding of factors that could cause a decrease in malicious online comments.

• 대한지역사회영양학회지
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• 제16권1호
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• pp.98-112
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• 2011

This study aimed to suggest a 1300 scale of a middle school foodservice facility floor plan which was compliant to the principle of HACCP, as well as ensuring food and work safety, and the flow of personnel and food materials. which consisted of 46 nutrition teachers and 6 experts, responded with a questionnaire on the relationship of functional area and space. Using their opinions, key principles for the design of the facility were single direction movement of food materials, customers and workers; minimization of the cross-contamination through the separation of functional space; and securement of customer-focused efficiency; staff-centered convenience and efficiency; and work and food safety. After the completion of an adjacency diagram, bubble diagram and program statement, the functional areas of a 1300 scale middle school food-service facility were allocated as follows: $9.9\;m^2$ for the receiving area, $56.1\;m^2$ for the pre-preparation area, $10.5\;m^2$ for the food storage area, $6.0\;m^2$ for the supplies storage area, $97.8\;m^2$ for the cooking area, $33.6\;m^2$ for the service area, $52.5\;m^2$ for dish washing area, cafeteria $410.5\;m^2$, $4.5\;m^2$ for the front room, for a total of $725.8\;m^2$. Expert groups have pointed to limitations within this model as there are no windows in the office for the influx of fresh outside air and a need for the straight line installation of steam-jacket and frying kettles on the sides of windows. This study can be useful as the guidelines for estimating the investment cost of the facility and placing the placement of functional areas and equipment in the renovation of the facility. It can be also useful data for a methodology of foodservice facility design.

• 천문학회보
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• 제41권2호
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• pp.44.1-44.1
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• 2016

The Sagittarius-Carina spiral arm in the Galaxy contains several massive young open clusters. We present a deep optical photometric study on the massive young open clusters in the Sagittarius-Carina arm, Westerlund 2 and the young open clusters in the ${\eta}$ Carina nebula. Westerlund 2 is a less studied starburst-type cluster in the Galaxy. An abnormal reddening law for the intracluster medium of the young starburst-type cluster Westerlund 2 is determined to be $R_{V,cl}=4.14{\pm}0.08$. The distance modulus is determined from zero-age main-sequence fitting to the reddening-corrected color-magnitude diagrams of the early-type members to be $V_0-M_V=13.9{\pm}0.14mag$. The pre-main sequence (PMS) members of Westerlund 2 are selected by identifying the optical counterparts of X-ray emission sources from the Chandra X-ray observation and mid-infrared emission sources from the Spitzer/IRAC (the Infrared Array Camera) observation. The initial mass function (IMF) shows a slightly flat slope of ${\Gamma}=-1.1{\pm}0.1$ down to $5M_{\odot}$. The age of Westerlund 2 is estimated to be. 1.5 Myr from the main-sequence turn-on luminosity and the age distribution of PMS stars. The ${\eta}$ Carina nebula is the best laboratory for the investigation of the Galactic massive stars and low-mass star formation under the influence of numerous massive stars. We have performed deep wide-field CCD photometry of stars in the ${\eta}$ Carina nebula to determine the reddening law, distance, and the IMF of the clusters in the nebula. We present VRI and $H{\alpha}$ photometry of 130,571 stars from the images obtained with the 4m telescope at Cerro Tololo Inter-American Observatory (CTIO). RV,cl in the η Carina nebula gradually decreases from the southern part (~4.5, around Trumpler 14 and Trumpler 16) to the northern part around Trumpler 15 (~3.5). Distance to the young open clusters in the ${\eta}$ Carina nebula is partly revised based on the zero-age main-sequence fitting to the reddening-corrected color-magnitude diagrams (CMDs) and the (semi-) reddening-independent CMDs. We select the PMS members and candidates by identifying the optical counterparts of X-ray sources from the Chandra Carina Complex Survey and mid-infrared excess emission stars from the Spitzer Vela-Carina survey. From the evolutionary stage of massive stars and PMS stars, we obtain that the northern young open cluster Trumpler 15 is distinctively older than the southern young open clusters, Trumpler 14 (${\leq}2.5 Myr$) and Trumpler 16 (2.5-3.5 Myr). The slopes of the IMF of Trumpler 14, Trumpler 15, and Trumpler 16 are determined to be $-1.2{\pm}0.1$, $-1.5{\pm}0.3$, and $-1.1{\pm}0.1$, respectively. Based on the RV,cl of several young open clusters determined in this work and the previous studies of our group, We suggest that higher RV,cl values are commonly found for very young open clusters with the age of < 4 Myr. We also confirm the correlation between the slope of the IMF and the surface mass density of massive stars.

• 건축역사연구
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• 제3권2호
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• pp.47-66
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• 1994

Chosun dynasty had accepted the Confucianism as a means of governing whole society and in its practical aspect ${\ulcorner}$Garye${\lrcorner}$ and the ceremonies of family ritual regarded as important. As a result, after mid-Chosun dynasty family ritual was begun to popularized on a national scale, and the socio-culture system which was interrelated with it changed into confucian ones. These fill-scaled change, on the other hand, resulted into the change of spatial use and plan type of yangban houses. In this aspect, this study intends to clarify the influence of family ritual on spatial use of yangban houses through the comparison between ideal pattern and behavioral one of family ritual. And this study made Gwanhonrye except Sangjerye an object because these two ceremonies were peformed in sucession in those day's behavior. The research setting is the Korean traditional society prior to modernization. The collected materials are based on ethnographic information as well as personal documents, public records, field works and the books on family ritual. The methodology for the present study is primarily based on the comparison study between available documents and field work. Especially, as the books on family ritual include some explanatory diagrams of the ideal pattern, these diagrams are compared with another ones made by the author of the behavioral pattern. The major findings are as follows. Firstly, in the aspect of Gwanhonrye's process, the ideal pattern is similar to the behavioral one. But even the essential course of the ideal pattern of Honrye is 'chinyoung', it has never been accepcted in Chosun dynasty on account of 'seoryubuga'. Secondly, even though the names of the performing space of family ritual are different each pattern, the methods of spatial use in processing these two ceremonies are similar. In other words, according to the books on family ritual the major performing spaces of Gwanhonrye are 'chungsa' and 'jungchim', but in practical process of both ceremonies 'sarangchae' and 'anche' are used. Lastly, as family ritual like Gwanrye and Honrye had been practiced at yangban houses after mid-Chosun dynasty as mentioned above, the spatial arrangement had to be changed to a certain extent.

• 대한기계학회논문집A
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• 제35권8호
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• pp.889-897
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• 2011

본 연구에서는 핵연료 지지격자체의 재료인 Zircaloy-4 와 Zirlo 판재의 이론적 성형한계 예측모델을 제시했다. 먼저 인장시험 및 이방성시험으로 응력-변형률곡선과 이방성계수를 획득했으며, NUMISHEET 96을 따르는 돔장출시험으로 두 재료의 실험적 성형한계도들을 얻었다. 이론적 성형한계도는 성형한계모델과 항복조건의 영향을 받는다. Swift 확산네킹이론, Marciniak-Kuczynski 의 재료결함 모델, Storen-Rice 의 정점이론을 이용해 부변형률이 양인 구간에서의 성형한계 곡선을 구했으며, 부변형률이 음인 구간에는 Hill 의 국부네킹 이론을 적용했다. 또한 재료이방성을 고려하기 위해 Hill 48, Hosford 79 항복조건을 사용 했다. Swift 확산네킹모델 (Hill 48 항복조건 적용)과 Hill 모델은 각각 변형률비가 양과 음인 영역에 대해 Zircaloy-4의 성형한계도를 비교적 정확히 예측하며, Zirlo의 성형한계도는 Hosford 79 항복조건 (a = 8)을 적용한 Storen-Rice 모델로 나타낼 수 있다.

• 한국인터넷방송통신학회논문지
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• 제9권4호
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• pp.145-152
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• 2009

본 우리나라 고리원전 1호기의 주제어실은 2007년에 부분 개선되었고 2013년에 완전 개량형화 될 예정이다. 부분 개선을 통해 원래의 아나로그 설비를 일부 대체하는 디지털 제어설비가 도입되었으며 안전변수표시 장치같이 단독으로 사용되던 전산시스템이 발전소 전산시스템에 통합되었다. 2015년에는 디지털화를 바탕으로 한 한국표준원전주제어실의 개량이 예정되어 있으나 현장 엔지니어와 운전원들은 개량형주제어실에 대해 호의적이지 않은 실정이다. 따라서 현장 운전원과 엔지니어들의 수용성을 제고하고 또한 사용자 인터페이스와 계측제어 구조를 평가하기 위한 표준형원전의 개량형주제어실 모형이 개발되었으며 모형에는 운전원들의 업무 지원성을 향상시킬 수 있도록 화면이 다중 층으로 구성되며 층간에는 상황추종메뉴로 연결되어 있는 P&ID 베이스 디스플레이 시스템이 채택되었다. 이 시스템은 첫 번째 층에는 간략화 된 P&ID가 디스플레이 되고 계속해서 자세한 추가 정보를 디스플레이 할 수 있도록 고안하였다. 디지털 시스템의 신뢰성과 운전성을 고려한 한국표준원전 개량형주제어실(MCR)의 최종형태가 제시되었으며 추가해서 운전에 영향을 미치지 않도록 발전소 정기보수 기간 중에 주제어실 현대화 작업을 수행할 수 있는 방안이 제시되었다.

• 한국건설관리학회논문집
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• 제19권6호
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• pp.124-134
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• 2018

모듈러 주택은 많은 장점이 있음에도 불구하고, RC구조에 익숙한 소비자들의 모듈러 주택에 대한 낮은 선호도가 모듈러 주택의 높은 공사비를 초래하고 있다. 모듈러 건축물의 공사비는 RC 구조 대비 130% 전후로 형성되어 있어 모듈러 건축물의 경제성 확보가 시급하다. 따라서 본 연구에서는 모듈러 주택의 공종별 절감가능 금액을 산출한 후, 장기적 관점에서의 경제성 분석을 진행하였다. 연구 진행을 위해 모듈러 주택의 내역서를 공장제작분 및 현장설치분으로 분개하여 공종별 발생하는 재료비, 노무비, 경비를 비교 분석을 진행했다. 그 후 파레토도를 작성하여 비용 누계 80% 내외에 포함되는 핵심 공종을 찾아 공사비 절감 가능대상으로 선정하였다. 국내 모듈러 건축의 시장규모가 일본, 유럽 국가 등 모듈러 선진국 수준과 비슷하다는 가정하에 전문가 인터뷰를 통해 모듈러 공법의 특성을 반영한 비용절감 방법을 설정하였고, 모듈러 업체 전문가를 대상으로 한 설문조사를 통해 비용절감 방법을 적용했을 때의 공종별 절감 가능 금액을 산출하고, 총 절감가능 금액을 산출했다. 비용절감 방법 중 '자동화 및 기계화'방법을 적용했을 때의 절감가능성이 1.54%로 가장 큰 것을 알 수 있었고, 국내 모듈러 생산 과정이 전자동화 및 기계화가 된다면 공사비 절감 뿐만 아니라 공기 단축도 기대해 볼 수 있다고 판단한다.

• 마이크로전자및패키징학회지
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• 제17권4호
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• pp.73-76
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• 2010

A two-facet approach was used to investigate the parametric performance of functional high-speed DDR3 (Double Data Rate) DRAM (Dynamic Random Access Memory) die placed in different types of BGA (Ball Grid Array) packages: wire-bonded BGA (FBGA, Fine Ball Grid Array), flip-chip (FCBGA) and lead-bonded $microBGA^{(R)}$. In the first section, packaged live DDR3 die were tested using automatic test equipment using high-resolution shmoo plots. It was found that the best timing and voltage margin was obtained using the lead-bonded microBGA, followed by the wire-bonded FBGA with the FCBGA exhibiting the worst performance of the three types tested. In particular the flip-chip packaged devices exhibited reduced operating voltage margin. In the second part of this work a test system was designed and constructed to mimic the electrical environment of the data bus in a PC's CPU-Memory subsystem that used a single DIMM (Dual In Line Memory Module) socket in point-to-point and point-to-two-point configurations. The emulation system was used to examine signal integrity for system-level operation at speeds in excess of 6 Gb/pin/sec in order to assess the frequency extensibility of the signal-carrying path of the microBGA considered for future high-speed DRAM packaging. The analyzed signal path was driven from either end of the data bus by a GaAs laser driver capable of operation beyond 10 GHz. Eye diagrams were measured using a high speed sampling oscilloscope with a pulse generator providing a pseudo-random bit sequence stimulus for the laser drivers. The memory controller was emulated using a circuit implemented on a BGA interposer employing the laser driver while the active DRAM was modeled using the same type of laser driver mounted to the DIMM module. A custom silicon loading die was designed and fabricated and placed into the microBGA packages that were attached to an instrumented DIMM module. It was found that 6.6 Gb/sec/pin operation appears feasible in both point to point and point to two point configurations when the input capacitance is limited to 2pF.