• Journal of Environmental Science International
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• v.24 no.11
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• pp.1417-1430
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• 2015

In this study we were to explore the seasonal variation of water temperature distributions before and after weir construction at Gumi, Chilgok, Gangjung(Goryung), Dalsung in the Nakdong River using Landsat satellite images. Relationship between in-situ water temperature and radiance values of Landsat-5, 7, 8 satellite images showed high correlation. Seasonal variation of water temperature in Nakdong River showed that the fluctuation ranges of water temperature before weir construction were larger than those after weir construction. This indicated that the variation of water temperature is due to the difference of heat storage volume by weir construction and dredging work. In particular, the water temperature after weirs construction in autumn was 4-8 times lower than that before weirs construction. Water temperature after weir construction decreased in spring and summer at the downstream of Gumi weir and Gangjung(Goryung) weir, and the upstream of Dalsung weir. In autumn and winter, the water temperature after weir construction increased in the upstream and downstream of the whole weirs except upstream of Gumi weir. Relationship between water temperature and meteorological elements (air temperature, wind speed, sunshine, radiation) showed high correlation of above 94% in air temperature, and then radiation was high correlation before and after 65%.

• Journal of Environmental Science International
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• v.18 no.1
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• pp.33-39
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• 2009

Based on the monthly weather report of Korea Meteorological Administration (KMA) and daily sea surface temperature (SST) data from National Fisheries Research and Development Institute (NFRDI) in 2006, heat budget was estimated at Gampo in the eastern coast of Korea, the region occuring the cold water known as upwelling in summer. Net heat flux was transported from the air to the sea surface during February to November, and it amounts to $345Wm^{-2}$ in monthly mean value. During December to January, the transfer of net heat flux was conversed from the sea surface to the air with $-56Wm^{-2}$ in minimum of monthly mean value in January. Long wave radiation was ranged from $6Wm^{-2}\;to\;106Wm^{-2}$. Sensible heat was varied from $-36Wm^{-2}$(June) to $61Wm^{-2}$(February) and showed negative values from April to August. Latent heat showed $20Wm^{-2}$(July) with its minimum in July and $49Wm^{-2}$ with its maximum in March in monthly mean value. The annual mean of net heat flux is $129Wm^{-2}$, giving an annual heat surplus of $22Wm^{-2}$. Thus, during summer, the upwelled cold water at Gampo, appears to compensate the heat gain. However the ways in which these compensations are accomplished remains to be clarified.

• Journal of Korean Medicine Rehabilitation
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• v.30 no.3
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• pp.117-127
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• 2020

Objectives The purpose of this study was to compare the effect of herb medication based on 'Go-bang' treatment, 'Huse-bang' treatment for patients with acute neck pain caused by traffic accidents. Methods We studied 40 patients with acute neck pain after traffic accidents who had admitted to Department of Korean Medicine Rehabilitation, College of Korean Medicine, Daejeon University from November 25, 2018 to November 25, 2019. 20 patients had received Herb Medication Based on 'Go-bang' and 20 patients had received herb medication based on 'Huse-bang' three times a day. The study was conducted as a retrospective observation study which analyze the patient's medical records. We used visual analogue scale (VAS) to evaluate pain reduction and neck disability index (NDI) to evaluate function improvement twice (hospitalization day and 5 days later). Statistical analysis was performed using the IBM SPSS statistics 25 program. Result The VAS scores, NDI scores decreased statistically significantly after treatment in all patients. Both 'Go-bang' and 'Huse-bang'groups showed a statistically significant VAS reduction and improvement of NDI on the fifth day of hospitalization. In the 'Huse-bang' group, there was a statistically significant improvement of NDI than in the 'Go-bang' group. Conclusion We found that both types of herbal-medication were significantly effective on acute neck pain and neck disability after traffic accident. Further study is needed about the comparison of effectiveness between Go-bang' and 'Huse-bang'groups.

• Advances in pediatric surgery
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• v.3 no.2
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• pp.117-125
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• 1997

Seventy neonates with congenital intestinal atresia and stenosis who were treated at pediatric surgical service. Hanyang University Hospital from September 1979 to December 1996 were analyzed retrospectively. The lesion occurred in 27 cases at the duodenum, in 26 cases at the jeiunum, in 13 cases at the ileum and in 2 cases at the pylorus and colon each. There were 10 multiple atresias and 7 apple-peel anomaly cases. The atresia predominated over the stenosis by the ratio of 4 : 1. Male to female ratio was 1.3 : 1. The average gestational age was 38 weeks, and the average birth weight was 2,754 grams. Though 22.9 % were borne prematurely and 34.3 % had low birth weight, 92.3 % of them had a weight appropriate for gestational age. Polyhydramnios(40 %) was more frequently observed in duodenal and jeiunal atresia while microcolon in ileal atresia(58.3 %). Weight loss and electrolyte imbalance occurred more frequently in the duodenal stenosis cases because of delayed diagnosis. Twenty(55.6 %) of 37 jeiunoileal atresia cases had evidence of intrauterine vascular accident : 4 intrauterine intussusception, 3 intrauterine volvulus and 3 strangulated intestine in gastroschisis, and 10 cases of intrauterine peritonitis. There were one or more associated anomalies in 45 patients (64.3 %). Preoperatively proximal loop volvulus developed in 3 cases and proximal loop perforation in 5 cases and one case each of distal loop perforation, duodenal perforation and midgut volvulus occurred in the jeiunoileal atresia. Overall mortality rate was 20 %.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.3 s.94
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• pp.327-334
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• 2005

In this paper, a new PAPR reduction method using correlation of input data sequence is proposed in order to overcome the serious drawbacks, such as necessity of side information transmission or increase of system complexity and calculation which are the basis of previous SLM, PTS and DSI method. A new PAPR reduction method can be classified into Method 1 and Method 2. Method 1 reduces the correlation between the smallest sub-sequence and neighbor smallest sub-sequence. And, to consider the own correlation in detail, the Method 2 reduces two case of correlation between neighbor smallest sub-sequences and neighbor largest sub-sequences. According to simulation result, Method 1 and Method 2 has about 0.5 $\~$ O.8 dB and 1 $\~$ l.2 dB PAPR reduction effect respectively. If more detailed process to reduce the correlation of input data sequence is considered, we can achieve better PAPR reduction performance.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.10
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• pp.1030-1035
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• 2003

In this paper, we compare the performance of IS-OFDM(interference suppressing orthogonal frequency division multiplexing) system with that of the conventional OFDM system. Each parallel branch symbol of IS-OFDM is multiplied by the orthogonal sequence and distributed into all sub-carriers. Then, each sub-carrier transmits information composed of the symbol components of all parallel branches in the given frame. The structure of IS-OFDM shows the frequency diversity characteristic. Therefore, IS-OFDM can be robust to the narrowband interference. BER performances are found in the narrow-band interference and a harmonic noise channels. When JSR(Jamming to signal ratio) increases from -10 dB to +10 dB in the constant interference bandwidth, IS-OFDM outperforms the conventional OFDM and the BER difference between IS-OFDM and OFDM is reduced as JSR increases. Also, the similar properly can be shown when interference bandwidth increases at the constant JSR. In the harmonic noise channel, we can find the good performance of IS-OFDM when the h-rate(harmonic noise bandwidth to signal bandwidth ratio) increases from 0.01 to 0.8. So, simulation results show that the IS-OFDM is more robust to the interference than the conventional OFDM.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.11 s.102
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• pp.1147-1154
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• 2005

In this paper, we propose some PAPR(Peak to Average Power Ratio) reduction methods using WHT(Walsh Hadamard Transform) to reduce high PAPR generated in OFDM system because of multi carrier modulation. These proposed methods are the methods which has additional PAPR reduction performance without a loss of bandwidth efficiency and a large increment of calculation complexity than common PAPR reduction methods by combining the WHT with some common methods. In this paper, we propose two PAPR reduction methods made by combining a SLM(Selective Mapping) and DSI(Dummy Sequence Insertion) with a WHT. From simulation result, we can find that the PAPR reduction methods using a WHT can get about 1 dB additional PAPR reduction performance than common PAPR reduction methods; they are SLM and DSI. And, because our proposed methods have not only PAPR reduction effect, but also frequency diversity effect, more stabile data transmission is possible in nonlinear HPA and multipath fading channel.

• Proceedings of the Korean Environmental Health Society Conference
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• 2002.04a
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• pp.40.1-43
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• 2002

The purpose of this study was to evaluate a new sampling and analytical method for the determination of hexavalent chromium, Cr(VI) in mist from field plating operation. The Procedures of this new method (Shin & Paik's Method) are as the following: Airborne hexavalent chromium is collected on polyvinyl chloride (PVC) filter according to the National Institute for Occupational Safety and Health (NIOSH) Method 7600, and the filter sample is placed in a screw-capped vial and soaked with 2％ NaOH/3％ Na₂CO₃ solution immediately after sampling. The Cr(VI) sample is analyzed by ion chromatography/visible spectrophotometry (IC/VS) according to the U.S. Environmental Protection Agency (EPA) Method 218.6. The airborne Cr(VI) concentrations measured by this method were compared with those determined by three reference methods: One (NIOSH/EPA Method) consisted of sampling airborne Cr(VI) on PVC filters and storing the sample filters in screw-capped vials according to the NIOSH method, and analyzing Cr(VI) in samples using IC/VS according to the EPA method. The second method (Impinger Method/NaHCO₃) consisted of absorbing airborne Cr(VI) into 0.02 MN/sub a/Hco₃ solution in midget impinger, and analyzing the Cr(VI) in samples using IC/VS. The third method was the OSHA Method Id-215. Using these four different methods, four replicates of air samples were collected at an electroplating process and analyzed simultaneously. Two-way ANOVA and Paired t-test were used to test difference among values determined by the methods. There was no significant difference and a strong correlation (r/sup 2/=0.99) between Cr(VI) concentrations measured by the shin & Paik's Method and an impinger method (p＞0.05). However, Cr(VI) concentrations determined by Shin & Paik's Method were Significantly different form those by the NIOSH/EPA Method (p＜0.05) or the OSHA method (p＜0.05). The Cr(VI) concentrations of Shin & Paik's Method were Significantly higher than those of the NIOSH/EPA Method or the OSHA method. We concluded that the Shin & Paik's Method could prevent Cr(VI) losses caused by reduction and give more reliable results of airborne Cr(VI) concentrations in work environments.

• Tuberculosis and Respiratory Diseases
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• v.42 no.2
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• pp.238-243
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• 1995

Sleep Apnea Syndrome is characterized by hypersomnolence, snoring, and sleep apnea. The symptoms of hypothyroidism include apathy, somnolence, lethargy, personality change, and intellectual deterioration and may be related to hypothyroid-related sleep disorders. Central, obstructive, and mixed patterns of sleep apnea may be observed in hypothyroidism. A 60-yr-old man was admitted due to hypersomnolence, snoring and generalized edema. Polysomnogram showed obstructive pattern of sleep apnea syndrome. Neck CT scan revealed narrowing of upper airway which is consistent with obstructive sleep apnea syndrome. Physical examination and hormonal study also disclosed the evidence of hypothyroidism. We report a case of sleep apnea syndrome due to primary hypothyroidism with review of literatures.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.10
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• pp.3048-3057
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• 1996

Analysis model containing two inclined surface cracks on semi-infinite elastic body is established and analyzed on the basis of linear fracture mechanics to examine mutual interference of two surface cracks. Muskhelishvili's complex stress functions are introduced and a set of singular integral equations is obtained for a dislocation density function. The stress intensity factors at crack tip are obtained by using the Gerasoulis'method. When two surface cracks are parallel and have the same length, the values of $K_1$and $\Delta K_11$(variation of $K_11$) for crack 1 and crack 2 decrease by the mutual interference of two surface cracks as the distance between the two surface cracks shortens. The effect of mutual interference is remarkable in high friction coefficient. In case that two surface cracks are parallel, the values of $K_1$and $\Delta K_11$for crack 2 decrease as the length ratio ot crack 2 to crack 1 becomes small. As the crack inclination angle rises, the value of $K_1$ and the mutual interference of $K_1$for crack 2 increase and the value of$\Delta K_11$ for crack 1 becomes smaller than that for crack 2.