• Korean Journal of Materials Research
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• v.4 no.1
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• pp.81-89
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• 1994

Ti film of lOnm thickness and Co film of 18nm thickness were sequentially e-heam evaporated onto Si (100) substrates. Metal deposited samples were rapidly thermal-annt.aled(KTA) in thr N1 en vironment a t $900^{\circ}C$ for 20 sec. to induce the reversal of metal bilayer, so that $CoSi_{2}$ thin films could be formed. The sheet resistance measured by the 4-point probe was 3.9 $\Omega /\square$This valur was maintained with increase in annealing time upto 150 seconds, showing high thermal stab~lity. Thc XRII spectra idrn tified the silicide film formed on the Si substrate as a $CoSi_{2}$ epitaxial layer. The SKM microgr;iphs showed smooth surface, and the cross-sectional TKM pictures revealed that the layer formed on the Si substrate were composed of two Co-Ti-Si alloy layers and 70nm thick $CoSi_{2}$ epl-layer. The AES analysis indicated that the native oxide on Si subs~rate was removed by TI ar the beginning of the RTA, and Ihcn that Co diffused to clean surface of Si substrate so that epitaxial $CoSi_{2}$ film could bt, formed. In thc rasp of KTA at $700^{\circ}C$. 20sec. followed by $900^{\circ}C$, 20sec., the thin film showed lower sheet resistance, but rough surface and interface owing to $CoSi_{2}$ crystal growth. The application scheme of this $CoSi_{2}$ epilayer to VLSI devices and the thermodynarnic/kinetic mechan~sms of the $CoSi_{2}$ epi-layer formation through the reversal of Co/Ti bdayer were discussed.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.3 no.1
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• pp.106-116
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• 1992

This study were purposed to find out parental perceptions of child adjustment associated with parenting stress with autistic children and differences of parenting stress between autistic children's parents and normal children's. Subjects were 27 autistic children's parents, 28 normal children's, 4 teachers with autistic children. 'Scales were Parenting Stress Index(PSI), Eyberg Child Behavior Index(ECBI), Childhood Autism Rating Scale(CARS), Social Maturing Scale(SMS). The results of this study were as follows. 1) In total parenting stress, parents with autistic children had significantly higher scores than normal's. 2) In child domain of parenting stress, fathers with autistic children had significantly higher than mothers on the other components except Mood and Demandingness. 3) In parent domain of parenting stress, parents with autistic children had significantly higher than nomal's on Restrict of role, Attachment, Sense of Competence. All mothers of normal and autistic children had significantly higher than fathers on the other components except Repression. 4) In parenting perceptions associated with parenting stress level of autistic children's parents. Low level group perceived their children as higher adaptibility than teacher's evaluation and high level group perceived them as equal to teacher's.

• Journal of Information Management
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• v.35 no.4
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• pp.1-16
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• 2004

In this paper, we outline the user interface problems that the text messaging users face to provide empirical basis for developing better improved mobile text messaging system. Our initial hypothesis was that the majority of the problems that the text messaging users face, namely, 1) difficulty in correctly understanding the intent of the incoming messages and 2) problem with frequently mis-addressing the recipient of the outgoing messages, can be accounted for by the poor usability of the text messaging user interface. Our analysis is based on the text message-based communication diaries, which were recorded for one week by each and every one of 75 college students, and survey taken from the same subjects. The data was collected in 2004. The students listed various difficulties including the limited message length, obscure input method, lack of mean to express emotional content, lack of receipt confirmation, lack of auto save feature when preparing messages to send, and lack of means to permanently save messages. Some of these problems were also identified in the previous studies. However, we were able to gather additional problems that the users face and also elicit potential solutions to remedy the problems. From these findings and analysis, we attempted to provide ways to improve the text messaging user interface.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.2349-2354
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• 2014

While the number of smart phone subscribers excessing 30 million people, Korea is leaping into the 'smart powerhouse' from IT powerhouse. The popularizat+ion of smart devices so called 'PC in the hand', brought surely change to people's life style, and also it had led to a revolutionary change to and also to business and government. In several corporations of each countries, a variety of smart devices smart devices such as smart phone, tablet PC and E-books have been developing. Nowadays, the usage of the smart phone is not only the simple function calling. It has become a culture of the terminal type in the hand anywhere at any time, which makes can communicate with the others in anywhere and anytime. However, some of the subscribers who visit the website for PC version with the mobile devices screen, can feel kind of discomfort while surfing the net on a smartphone devices because the install of the existing video and flash files and the screen size for computer is not available for mobile devices. Therefore, in this paper, we studied on effective mobile contents generation program using QR code that is two dimensions bar code under the smart device environment. Also, unlike previous QR code generator that decorate standardized design, we realize an original QR code generation system from user perspective.

• Economic and Environmental Geology
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• v.56 no.6
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• pp.765-779
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• 2023

The Daum Vent Field (DVF) was newly discovered in the Central Indian Ridge during the hydrothermal expedition by the Korea Institute of Ocean Science & Technology (KIOST) in 2021. In this paper, we describe the detailed mineralogy and geochemistry of hydrothermal chimney and mound to understand the nature of hydrothermal mineralization in the DVF. The mineral assemblages (pyrite±sphalerite±chalcopyrite) of dominant sulfides, FeS contents (mostly <20 mole %) of sphalerite, and (Cu+Zn)/Fe values (0.001-0.22) of bulk compositions indicate that the DVF has an strong affinity with basaltic-hosted seafloor massive sulfide (SMS) deposit along the oceanic ridge. Combined with the predominance of colloform and/or dendritic-textured pyrite and relatively Fe-poor sphalerite in chimneys, the fluid-temperature dependency of trace element systematics (Co, Mn, and Tl) between chimney and mound indicates that the formation of mound was controlled by relatively reducing and high-temperature fluids compared to chimney. The δ³⁴S values (+8.31 to +10.52‰) of pyrite reflect that sulfur and metals were mainly leached from the associated basement rocks (50.6-61.3%) with a contribution from reduced seawater sulfur (38.7-49.4%). This suggests that the fluid-rock interaction, with little effect of magmatic volatile influx, is an important metal source for the sulfide mineralization in the DVF.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.11 s.353
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• pp.37-47
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• 2006

This work proposes a 10b 25MS/s $0.8mm^2$ 4.8mW 0.13um CMOS A/D Converter (ADC) for high-performance wireless communication systems such as DVB, DAB and DMB simultaneously requiring low voltage, low power, and small area. A two-stage pipeline architecture minimizes the overall chip area and power dissipation of the proposed ADC at the target resolution and sampling rate while switched-bias power reduction techniques reduce the power consumption of analog amplifiers. A low-power sample-and-hold amplifier maintains 10b resolution for input frequencies up to 60MHz based on a single-stage amplifier and nominal CMOS sampling switches using low threshold-voltage transistors. A signal insensitive 3-D fully symmetric layout reduces the capacitor and device mismatch of a multiplying D/A converter while low-noise reference currents and voltages are implemented on chip with optional off-chip voltage references. The employed down-sampling clock signal selects the sampling rate of 25MS/s or 10MS/s with a reduced power depending on applications. The prototype ADC in a 0.13um 1P8M CMOS technology demonstrates the measured DNL and INL within 0.42LSB and 0.91LSB and shows a maximum SNDR and SFDR of 56dB and 65dB at all sampling frequencies up to 2SMS/s, respectively. The ADC with an active die area if $0.8mm^2$ consumes 4.8mW at 25MS/s and 2.4mW at 10MS/s at a 1.2V supply.

• The Journal of the Korea Contents Association
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• v.16 no.8
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• pp.90-96
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• 2016

The 3390 million people, around 83% of the adult population in Korea use smartphone. Although the safety problem of the certificate has been occurred continuously, most of these users use the certificate. These safety issues as a solution to 'The owner of a mobile phone using SMS authentication technology', 'Biometric authentication', etc are being proposed. but, a secure and reliable authentication scheme has not been proposed for replace the certificate yet. and there are many attacks to steal the certificate and private key. For these reasons, security experts recommend to store the certificate and private key on usb flash drive, security tokens, smartphone. but smartphones are easily infected malware, an attacker can steal certificate and private key by malicious code. If an attacker snatchs the certificate, the private key file, and the password for the private key password, he can always act as valid user. In this paper, we proposed a safe way to keep the private key on smartphone using smartphone's unique information and user password. If an attacker knows the user password, the certificate and the private key, he can not know the smart phone's unique information, so it is impossible to use the encrypted private key. Therefore smartphone user use IT service safely.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.8 no.4
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• pp.49-56
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• 2013

KakaoTalk, a Korean mobile instant messenger service launched by KAKAO Inc., has grown remarkably popular in a short period of time, with its number of subscribers exceeding 100 million as of July 2013. Today, KakaoTalk is an everyday communication tool among most Korean mobile users. Although KAKAO has been the subject of many business and consumer studies, the KakaoTalk platform strategy has not been studied thoroughly. In this study, we analyze its platform strategy through the lens of several widely utilized frameworks such as Platform Leadership (Gawer & Cusumano 2002, 2008), Winner-take-all dynamics (Eisenmann et al. 2006), and Open Service Innovation (Chesbrough 2011). Our results show that Eisenmann et al (2006)'s "Winner-Take-All" platform best explains how KakaoTalk dominated its rivals, Mypeople by Daum Communications and Line by Naver Corporation. In surpassing its rivals, KAKAO delivered a solution to the 'essential problem' that mobile social communication should be upgraded from mobile companies' paid "Short Message Service" (SMS). By doing so, KakaoTalk fulfilled the first requirement of Gawer & Cusumano (2008)'s "Coring" strategy, which explains how a new platform is created. KakaoTalk also satisfied the second requirement of "Coring" by providing economic incentives for KakaoTalk members to interact through its Games and Items store. Actively accepting its customers' ideas and upgrading its services, KAKAO reinforced its platform leadership to its customers and put Chesbrough (2011)'s "Outside In - Open Service" innovation strategy into practice.

• Journal of The Korean Society of Agricultural Engineers
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• v.49 no.5
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• pp.11-20
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• 2007

In this study, we reviewed the optimal space for the fishway and fish storage establishment in the section between the downstream of the Hwacheon dam and the confluence of the Pungsan river. The hydraulic stability of these facilities was also examined. In the section between the downstream of Hwacheon dam and the confluence of Pungsan river, the release flow of Hwacheon dam was set at $5,495m^3/s,\;6,110m^3/s$ and $7,537m^3/s$, and numerical simulations were executed for each instance using the HEC-RAS model and RMA-2. In the analysis of the flow velocity distributions in the subject section by release flows of Hwacheon dam, it was shown that there was over 5.0m/s of high flow velocity at Sta. $#1{\sim}Sta.$ #3, Sta. $#4{\sim}Sta.$ #6, and Sta. $#12{\sim}Sta.$ #13 of the sections analyzed in this study. The Sta. $#0{\sim}Sta.$ #1 was considered appropriate for the fishway and fish storage establishment. As seen in the results of the numerical stability review by release flow conditions of Hwacheon dam subject to the selected available areas fur fishway and fish storage, the topographically available section for the establishment of fishway and fish storage exists at Sta. $#1{\sim}Sta.$ #3 when the release flow of Hwacheon dam is $5,495m^3/s$, whereas Sta. $#0{\sim}Sta.$ #1 should be reviewed for the subject section for the establishment of fishway at release flows of $6,110m^3/s$ and $7,537m^3/s$, in addition to the figures gathered at the $5,495m^3/s$ release flow. Finally, the available section for the establishment of fishway and fish storage was determined to be Sta. $#0{\sim}Sta.$ #3. Further, if fishway and fish storage are established in the outer bank within this section, the high flow velocity section should be avoided. An alternative would be to establish for the fishway in the inner band on the section of Sta. #1 or Sta. #3.

• Quality Improvement in Health Care
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• v.15 no.1
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• pp.89-100
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• 2009

문제: 소화기병검사실에서 대장내시경 검사의 부도건수가 최근 월 200명 정도로 예약인원의 16%에 달한다. 이는 본원 외래진료 부도율이 평균 10%인 것과 비교할 때 상당히 높은 결과이므로 대장내시경 예약환자를 대상으로 부도율 관리를 위한 활동이 필요하였다. 목적: 외래 및 입원환자의 부도건수 및 부도환자의 특성을 분석하고, 개선활동을 통하여 대장내시경 검사의 부도율을 줄인다. 의료기관: 서울 아산병원. 질 향상 활동: 부도관리를 위한 개선활동으로 SMS 횟수를 2주전, 4일전, 1일전 3회로 변경하고, 내용도 각 시기마다 차별화하였다. 대장내시경 검사 예약을 하고 기다리는 환자를 대상으로 처방일 순, 예약 날짜순서 등 필요한 항목 순으로 볼 수 있는 리스트가 필요하여 예약대기 프로그램을 개발하였고, 처방일로부터 2주 이내 자동예약을 금지하였다.(7월 10일부터 시작) 예약대기명단에 있는 환자를 대상으로 전화로 예약 변경을 하여 2주 이내에는 예약의 빈자리가 없도록 하였다. 미리 부도를 예측하여 추가로 예약하던 방법에서 정원조정을 하여 정원 외 추가 예약을 하지 않았다. 입원환자 일정관리를 위하여 일정관리 프로그램을 개발하여 타과의뢰 회신을 하는 전임의가 직접 날짜를 전산에 입력하여 회신과 동시에 검사실, 담당주치의, 담당 간호사가 모두 일정을 확인할 수 있도록 하였으나 프로그램이 늦어져 9월 12일부터 시행하였다. 개선효과: 부도건수가 개선 전 8주 동안 385건(예약인원 대비 16%) 에서 개선 후 6주의 평가기간 동안 256건(예약인원대비 14.1%)으로 129건이 감소하였으며, 검사 1-2일전 일정 변경 연락 환자 감소 및 검사 비용 수납 환자의 부도건수가 감소하였다. 대장내시경 검사 예약대기 프로그램 운영 및 예약 변경 전화 활동으로 2달씩 기다리던 환자의 예약일을 약 한 달 정도 단축하여 줄 수 있었다. 검사 정원 관리의 결과로 검사 예약 시 예약기준이 명확해지고, 부적절한 예약으로 인한 검사지연 등이 확실히 줄었다. 또한 입원환자 일정관리 프로그램 적용으로 입원환자의 검사일정과 관련된 전화업무는 확실히 줄어들 것으로 예상된다.