Late Quaternary inner shelf deposits in response to late Pleistocene-Holocene sea level changes: Nakdong River, SE Korea

Yoo, D.G.,Kim, S.P.,Chang, T.S.,Kong, G.S.,Kang, N.K.,Kwon, Y.K.,Nam, S.L.,Park, S.C. Pergamon Press 2014 QUATERNARY INTERNATIONAL Vol.344 No.-

The high-resolution seismic profiles from the inner shelf off the Nakdong River in SE Korea can be directly correlated with the lithologic characteristics in the borehole data. These correlations offer an opportunity to document the evolution of the inner shelf deposits with sediment supplies in response to the late Quaternary sea level changes. The inner shelf sequence in this area consists of four sedimentary units, which comprise a set of lowstand, transgressive, and highstand systems tracts deposited since the last glacial maximum: incised-channel fill (SU1), estuary (SU2), sand veneer (SU3), and subaqueous delta (SU4). The lowermost unit (SU1), which overlies the sequence boundary, is interpreted as fluvial deposits formed during the last glacial period and the early stage of transgression, and belongs to the lowstand to transgressive systems tract. The lower middle unit (SU2) lying below the ravinement surface represents a paralic component that consists of estuarine sandy mud or muddy sand developed between approximately 13 and 8 cal ka BP, whereas the upper middle unit (SU3) above the ravinement surface corresponds to a marine component that consists of sand veneer produced by the shelf erosion during the ensuing sea-level rise. These two units (SU2 and SU3) belong to the transgressive deposits. The uppermost unit (SU4), regarded as the highstand systems tract, formed the Nakdong subaqueous delta including the proximal and distal systems developed after the highstand sea level at approximately 6 cal ka BP. The lateral transition from the proximal to distal facies suggests a prograding delta system in the Nakdong River.

자기 저항 센서의 민감성 향상에 관한 연구

장충근,손대락,유중렬,윤만영,김영일,박재형 경북대학교 센서기술연구소 1994 연차보고서 Vol.1994 No.-

본 연구에서는 MR센서의 민감성을 향상시키기 위하여 current path의 잡음 거동을 면밀히 조사 분석한 결과 센서의 잡음이 current path의 저항값에 의존함을 확인하고 저저항, 저잡음 MR 센서를 설계, 제작하였다. 이 과정에서 current path의 폭(w)과 두께(t)의 값이 추적되었으며 t/w=10^-3에서 가장 예리한 민감성이 확인되었다. 한편 센서의 선형성을 향상시키기 위하여 current path를 주축에 대하여 45°로 배열하였으며 지향성을 향상시키기 위하여 full brige센서를 half bridge센서로 분리하였다. 또한 높은 SNR을 얻기 위해 센서를 AC bias로 여기시키고 이 여기 유기된 신호를 동기 정류할 수 있도록 시스템을 설계 제작하였다. 이상의 연구에서 33V/T의 민감도를 얻었다. In this experiment we have investigated and carefully analyzed the' noise phenomena of the current path of magnetoresistive sensors for high sensitivity. We confirmed that the noise depended on the resistance of the current path. We likewise tried to manufacture the sensors which haxe low resistance and low noise characteristics. Also, when we increased the width of the current path and current density and decreased the width of gaps, the sensitivity of sensors was improved. In this process we have searched the value of current path thickness(t) and path width, and we obtained the best sensitivity in the ratio of t/w = 10^-3. On other hand we arranged the current paths to be inclined at an angle of 45 degrees from the main axis for the improvement of the linearity of the sensor response, and separated the full-bridge sensor to half bridge sensor in order to improve the sensor's directivity. Furthermore, exiting the sensor with AC bias in order to get higher SNR we manufactured a system that can synchronously rectify the signal induced by the excitation and obtained the sensitivity of 33V/T.

객체 중심 프로그램의 소프트웨어 척도

유철중,이종득,김용성,장옥배 全北大學校 基礎科學硏究所 1991 基礎科學 Vol.14 No.2

객체 중심 언어에 있어서 데이타 추상화에 의한 캡슐화와 상속성이 가장 중요한 개념으로 인식되고 있다. 특히, 프로그램이 객체간의 메시지 전달에 의해서 수행되고 상속에 의해 재사용되는 특성이 있으므로, 이러한 객체 중심 프로그램의 복잡도를 보다 잘 나타내기 위해서는 클래스에 기반을 둔 척도가 요구된다. 따라서 본 논문에서는 객체 중심 프로그램의 복잡도 측정에 적합한 복잡도 척도를 얻기 위해 고려하여야 할 특성들을 제시하였으며, 이를 바탕으로 클래스에 기반을 둔 새로운 복잡도 척도를 제안하고 그 타당성을 보였다.

자기저항센서를 이용한 자력계 제작에 관한 연구

장충근,유중열,남선우,손대락 경북대학교 센서기술연구소 1993 연차보고서 Vol.1993 No.-

자기저항 센서를 이용한 저자장 계측용 자력계를 제작하기 위하여 니켈·코발트(0.7Ni-0.3Co)합금을 유리기판에 600Å 두께로 진공증착한 후 박막을 bridge 구조의 격자 무늬로 사진 식각하는 과정에서 4개의 birdge arm을 주축과 45°의 각도를 유지하도록 배열하고 격자무늬의 면적율을 늘여서 자기저항 센서를 제작한 다음 센서에 유기된 자기저항 신호를 자속밀도로 변환시킬 수 있는 자력계를 제작하였다. 제작된 센서는 인가자장 범위 ±5×10 exp (-4)T에서 직선성이 양호하였으며 분해능은-132㏈이였고, 백색잡음은 -142㏈이었다. 그리고 주파수 대역폭은 -3㏈ point에서 445㎐이었으며 온도계수는 2.33㎵/℃이었다. 완성된 자력계의 민감도는 0.1μT 이었고 측정범위는 1μT∼1.999mT이었다. 그리고 analog 출력단자의 임피던스는 60ohm로 하였고 digital 출력은 3·1/2 LED로 가시화 시켰다. To manufacture low-field magnetometer using magnetoresistive(MR) sensors, we deposited thin layers 600Å of thickness Ni-Co(0.7Ni∼0.3Co) alloy on slide glasses. In the layers, we ordered 4 arms of the bridge sensors in the shape of grid structure be inclined at an angle of 45° to main axis and made increase the areal rate to 67% so that be manufactured as magnetometer that can transform the induced magnetoresistive signal to magnetic flux density after production of the MR sensors using the photolithographic process. While the response characteristic of the fabricated sensors had good linearity in the magnetic field of ±5×10 exp (-4)T ranges, the white noise was -142㏈ and the resolution -132㏈. The frequency band width was 445㎐ when the response amplitude ratio was -3㏈ point and temperature coefficient of the sensors was 2.33㎵/℃. The sensitivity of the accomplished magnetometer was 0.1μT, and measurement range was between 1μT and 1.999mT. We made the impedance of the analog output terminal in the magnetometer be 60ohm and also digital display was 3·1/2 LED.

Late Quaternary transgressive deposits in a low-gradient environmental setting: Korea Strait shelf, SE Korea

Yoo, D.G.,Kim, S.P.,Lee, C.W.,Chang, T.S.,Kang, N.K.,Lee, G.S. Pergamon Press 2014 QUATERNARY INTERNATIONAL Vol.344 No.-

Analysis of high-resolution seismic profiles and sediment data from the Korea Strait shelf reveals that the late Quaternary deposits in this area consist of five sedimentary units deposited during transgression phases of sea-level changes between about 15 and 6 ka BP: ancient beach/shoreface complex (unit P1), estuarine deposits (unit P2), mid-shelf sand sheet (unit M1), sand ridge system (unit M2), and inner-shelf sand sheet (unit M3). They are paralic and marine, separated by a ravinement surface. The lower paralic component below the ravinement surface consists of two sedimentary units (P1 and P2) preserved from shoreface erosion. The top surface of the paralic unit is truncated by a sharp erosional surface. This surface is overlain by three sedimentary units (M1, M2, and M3), which were produced by shoreface erosion that shifted landward during transgression. The transgressive deposits in this area, considering geometries and distribution patterns, can be divided into three types (I, II, and III). Type I overlying the lowstand systems tract is confined to the shelf margin, and consists of a thick paralic unit P1 and a relatively thin marine unit M1. Type II on the mid shelf has no paralic component and the marine units M1 or M2 directly overly the sequence boundary. Type III, found in the inner shelf, includes a thick paralic (unit P2) and a thin marine (unit M3) component. It is completely covered by the highstand systems tract.

Changing prevalence of glomerular diseases in Korean adults: a review of 20 years of experience

Chang, J. H.,Kim, D. K.,Kim, H. W.,Park, S. Y.,Yoo, T.-H.,Kim, B. S.,Kang, S.-W.,Choi, K. H.,Han, D.-S.,Jeong, H. J.,Lee, H. Y. Oxford University Press 2009 Nephrology, dialysis, transplantation Vol.24 No.8

<P>BACKGROUND: The prevalence of glomerular diseases differs according to geographic area, race, age and indications for a renal biopsy. This study was conducted to evaluate the distribution and changing patterns of renal diseases during the past 20 years in a large patient population in Korea. METHODS: Patients aged 16 years or older who underwent a renal biopsy at Severance Hospital in the Yonsei University Health System from 1987 to 2006 were enrolled. All medical records were reviewed retrospectively. RESULTS: In total, 1818 patients (M:F = 1.02:1) were reviewed. Glomerulonephritis (GN) comprised 85.9% of the total biopsied cases. The most common primary GN was IgA nephropathy (IgAN) (28.3%), which was followed by minimal change disease (MCD) (15.5%), membranous nephropathy (MN) (12.3%), focal segmental glomerulosclerosis (FSGS) (5.6%) and membranoproliferative GN (MPGN) (4.0%). The most common secondary GN was lupus nephritis (8.7%). The most common idiopathic nephrotic syndrome was MCD (38.5%), which was followed by MN and IgAN. Among 128 (7.4%) patients who were HBsAg-positive, MN (30.5%) and MPGN (21.1%) were the most common GN. When the incidence rates between 1987-91 and 2002-06 were compared, IgAN increased from 25.6 to 34.5%, while MCD (from 23.2 to 7.0%) and MPGN (from 6.7 to 1.7%) decreased significantly (P < 0.01). CONCLUSIONS: IgAN was the most common primary GN, and MCD was the most common cause of nephrotic syndrome. In the 5-year quartile comparison, the relative frequency of IgAN increased, while the relative frequency of MCD and MPGN decreased significantly during the past 20 years.</P>

아파트 베란다 화단 유형별 실내식물의 생장 반응

장영득(Y. D. Chang),송정섭(J. S. Song),김형득(H. D. Kim),유은하(E. H. Yoo),김광진(K. J. Kim),류병열(B. Y. Ryu) 한국원예학회 2005 한국원예학회 학술발표요지 Vol.2005 No.5

The impact of dialysis modality on skin hyperpigmentation in haemodialysis patients

Moon, S. J.,Kim, D. K.,Chang, J. H.,Kim, C. H.,Kim, H. W.,Park, S. Y.,Han, S. H.,Lee, J. E.,Yoo, T.-H.,Han, D. S.,Kang, S.-W. Oxford University Press 2009 Nephrology, dialysis, transplantation Vol.24 No.9

<P>BACKGROUND: Skin hyperpigmentation in end-stage renal disease (ESRD) patients has been attributed to the accumulation of middle-molecular-weight (MMW) substances. Although an MMW mechanism suggests that hyperpigmentation may be improved by high-flux haemodialysis (HF-HD) and haemodiafiltration (HDF), this possibility has not been explored. In the present study, we investigated the impact of different dialysis modalities on skin colour in HD patients. METHODS: Eighty-two ESRD patients on HD were divided into low-flux HD (LF-HD), HF-HD and HDF groups. The melanin index (MI) and erythema index (EI) of the abdomen and the flexor side of the forearm (non-sun-exposed areas) and the forehead (sun-exposed area) were determined by using a narrow-band reflectance spectrophotometer at baseline and after 12 months. RESULTS: Even though absolute values of baseline and follow-up MI and EI of the three sites were comparable among the three groups, forehead MI and EI were significantly decreased after 12 months in the HDF group (P < 0.05). In addition, the change in forehead MI was significantly greater in the HDF than in the LF-HD group (-1.0 +/- 2.4% versus 0.3 +/- 1.6%, P < 0.05). Moreover, beta(2)-microglobulin reduction rates were negatively correlated with both changes in forehead MI (P < 0.01) and EI (P < 0.05). CONCLUSIONS: Skin colour of sun-exposed areas was signi- ficantly decreased in ESRD patients receiving HDF therapy, suggesting that enhanced removal of MMW substances by convection may prevent or reduce hyperpigmentation in HD patients.</P>

An Analysis of Acoustic Features Caused by Articulatory Changes for Korean Distant-Talking Speech

Kim Sunhee,Park Soyoung,Yoo Chang D. The Acoustical Society of Korea 2005 韓國音響學會誌 Vol.24 No.e2

Compared to normal speech, distant-talking speech is characterized by the acoustic effect due to interfering sound and echoes as well as articulatory changes resulting from the speaker's effort to be more intelligible. In this paper, the acoustic features for distant-talking speech due to the articulatory changes will be analyzed and compared with those of the Lombard effect. In order to examine the effect of different distances and articulatory changes, speech recognition experiments were conducted for normal speech as well as distant-talking speech at different distances using HTK. The speech data used in this study consist of 4500 distant-talking utterances and 4500 normal utterances of 90 speakers (56 males and 34 females). Acoustic features selected for the analysis were duration, formants (F1 and F2), fundamental frequency, total energy and energy distribution. The results show that the acoustic-phonetic features for distant-talking speech correspond mostly to those of Lombard speech, in that the main resulting acoustic changes between normal and distant-talking speech are the increase in vowel duration, the shift in first and second formant, the increase in fundamental frequency, the increase in total energy and the shift in energy from low frequency band to middle or high bands.

DROWSY DETECTION BASED ON LOW OXYGEN CONCENTRATION LEVEL ESTIMATION

Oh Chul Kwon(권오철),Chang D. Yoo(유창동) 대한전자공학회 2017 대한전자공학회 학술대회 Vol.2017 No.6

This paper proposes a drowsy detection algorithm that determines change in skin color: studies have shown that skin color correlates well with oxygen supply to the brain which is a leading cause for drowsiness. Hemoglobin serves as a carrier of oxygen, and it can be in various states exhibiting different absorption spectrum: oxyhemoglobin is much more reddish than de-oxyhemoglobin while hemoglobin is much greener than oxyhemoglobin. The algorithm incorporates the Viola-Jones algorithm and HSV to detect face, and use normalized RGB to exclude the light source which appear as noise. Experiment result show that change in skin color is accurate measure for detecting drowsiness.