• Journal of Positioning, Navigation, and Timing
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• 제11권1호
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• pp.23-28
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• 2022

The eLoran system is a high-power terrestrial navigation system that is recognized as the most appropriate alternative to complement the GNSS's vulnerability to radio frequency interference. Accordingly, Korea has conducted eLoran technology development projects since 2016. The eLoran system developed in Korea provides 20 m positioning accuracy to maritime user in Incheon and Pyeongtaek harbor. To accurately calculate the position with the eLoran signal, it is necessary to apply a compensation method that mitigates the propagation delay. In this paper, we develop the compensation method to mitigate the eLoran signal propagation delay and evaluate the positioning performance in Incheon harbor. The propagation delay due to the terrain characteristics is pre-surveyed and stored in the user receiver. Real-time fluctuations in propagation delay compared to the pre-stored data are mitigated by the temporal correction generated at a nearby differential Loran station. Finally, two performance evaluation tests were performed to verify the positioning accuracy of the Korean eLoran system. The first test took place in December 2020 and the second in April 2021. As a result, the Korean eLoran service has been confirmed to provide 20 m location accuracy without GPS.

• 한국지형학회지
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• 제27권4호
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• pp.89-112
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• 2020

The purpose of this study is as follows: First, we restore the optimal topographical environment of the Bronze Age settlements in the Yongdu Stream and its surrounding area in Asan City. Second, we reveal the relative importance of the topographical factors that the Bronze Age people considered when selecting their dwelling locations. We compared and analyzed topographical factors (ridge scale, ridge direction, slope direction of the ridge, micro-landform of the ridge, position of the ridge) from the ridge's environmental perspective of 123 Bronze Age dwellings (hereinafter referred to as dwellings) found in the survey area for that purpose. The results are as follows: First, from a macro perspective, the optimal topographical environment for the location of the Bronze Age settlement is the second ridge that have the E-W direction. And from a micro perspective, it is the southeast direction slope of the Crest slope at the summit. Second, it appears that the Bronze Age people have taken important consideration in determining the location of their dwelling in the following order: ① position (eg. summit), ② micro-landform (eg. Crest slope, Upper slope), ③ slope direction (eg. southward, South, Southeast), ④ scale (eg. sub-ridge, secondary, tertiary), ⑤ direction (eg. E-W, NNE-SSE).

• 식물분류학회지
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• 제39권1호
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• pp.4-11
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• 2009

한국에 자생하는 겨우살이과 4종, 겨우살이, 참나무겨우살이, 동백나무겨우살이, 꼬리겨우살이 등에 대해 잎과 줄기의 해부학적 특징과 기주식물별 2차 흡기구조의 해부학적 특징을 조사하였다. 그 결과 잎과 줄기의 해부학적 특징으로 한국산 겨우살이과 4 분류군을 종과 속 수준에서 구별할 수 있는 것으로 파악되었다. 잎에서는 향축면과 배축면의 축, 중앙맥에 발달된 유관속 형태, 후벽세포의 발달 여부 등이, 줄기에서는 횡단면에서 줄기의 전체적인 형태, 큐티클층의 발달 정도, 유관속의 배열, 후벽세포와 수의 발달 여부 등이 표징형질로 조사되었다. 기주별 2차 흡기의 특징을 확인하기 위해 참나무겨우살이와 동백나무겨우살이에서 각각 7종류 및 5종류의 기주식물을 대상으로 지상부 흡기 발달 정도, 종단면에서 2차 흡기의 모양과 플랜지 발달 여부, 기주내 침투 지역과 흡기 축의 발달 여부, 2차 흡기에서 흡기세포의 위치와 짧은 흡기 가도관의 발달 여부 등 형질을 조사하였다. 조사된 형질에서 참나무겨우살이와 동백나무겨우살이는 뚜렷하게 구별되었다. 한편, 기주식물의 강도와 흡기의 발달 정도에 따라 2차 흡기의 전체적인 형태가 기주별로 다소 차이가 있었으나, 침투 지역, 흡기 짧은 가도관 세포의 발달 등 정성적인 형질들은 기주와 발달 정도에 영향을 받지 않고 항상 일정하여 계통학적으로 의미 있는 특징으로 파악되었다.

• Bulletin of the Korean Chemical Society
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• 제27권5호
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• pp.687-693
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• 2006

Chromium(III) complexes, cis-[Cr([14]-decane)$(HOC _6H _4COO) _2$]$ClO _4$ I and cis-[Cr([14]-decane)(OH) $(OC _6H _4NO _2)$]$ClO _4{\cdot}H _2O$ II ([14]-decane = rac-5,5,7,12,12,14-hexamethyl-1,4,8,11-teraazacyclotetradecane) are synthesized and structurally characterized by a combination of elemental analysis, conductivity, IR and VIS spectroscopy, and X-ray crystallography. The complexes crystallizes in the monoclinic space groups, $C2 _1$/a in I and $P2 _1$/n in II. Analysis of the crystal structure of complex I reveals that central chromium(III) ion has a distorted octahedral coordination environment and two hydrogensalicylato ligands are unidentate to the chromium(III) ion via the carboxyl groups in the cis-position. For monomeric complex I the hydrogensalicylato coordination geometry is as follows: Cr-O(average) = 1.984(3) $\AA$;Cr-N range = 2.105(3)-2.141(4) $\AA$;C(24)-O(4) = 1.286(5) $\AA$;N(2)-Cr-N(4) (equatorial position) = 96.97(15)${^{\circ}}$; N(1)-Cr-N(3) (axial position) = 168.27(15)${^{\circ}}$; O(1)-Cr-O(4) = 85.70(13)${^{\circ}}$. The crystal structure of II has indicated that chromium(III) ion is six-coordinated by four secondary amines of the macrocycle, hydroxide anion and nitrophenolate anion.

• 한국전문물리치료학회지
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• 제20권3호
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• pp.45-53
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• 2013

The purpose of this study was to examine the differentiation of proprioception, invertor and evertor muscle strength, and time to peak torque at a velocity of $300^{\circ}/sec$ of the ankle joint in people with or without functional ankle instability (FAI). Nineteen subjects with a history of ankle sprain participated. All subjects were divided into FAI group ($n_1=9$, Cumberland ankle instability tool (CAIT)${\leq}24$) and a control group ($n_2=10$) based on their CAIT scores. Isokinetic dynamometer was used to measure the sense of active joint position of the ankle at mid-range and end-range of an inversion motion and invertor as well as the evertor muscle strength and time to peak torque at $300^{\circ}/s$. The FAI group showed a statistically reduction in invertor and evertor muscle strength and time to peak torque when compared to the control group (p<.05). Muscle strength and time to peak torque of the invertor and evertor, as well as the sense of active joint position at end-range were also lower in the FAI group than in the control (p<.05). Correlations between CAIT score and position sense at end-range (r=-.577) and invertor muscle strength (r=.554) were statistically significant (p<.05). Individuals with FAI showed reduction in invertor and evertor muscle strength and recruitment time as well as in proprioception of the ankle joint. Thus, proprioception and invertor and evertor muscle strength of the ankle joint at fast angular velocity may be investigated when examining and planning care for individuals with FAI.

• 무역상무연구
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• 제40권
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• pp.3-30
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• 2008

This article attempts to describe and analyze the rules on the buyer's remedies for lack of conformity under PELS. It shows that such remedies under the PELS operate in a two-tier remedial scheme which is alien to both domestic and international legal systems. That is, repair and replacement take the position of primary remedy, whereas termination, price reduction and damages are secondary remedies which are available only where the primary remedies cannot be invoked. Notwithstanding its superiority, the PELS have some drawbacks in several aspects. First, the PELS seems to place its focus on the factor of cost except the other factors, for instance, the significance of the lack of conformity, when one decides whether the first tier remedies cause the seller unreasonable effort or expense. It is argued that the factors can be considered by referring to art. 1:302 PECL. Second, the PELS does not expressively provide any exclusion of the seller's right to choose between repair or replacement on the basis of unreasonable uncertainty in reimbursing the expenses advanced by the buyer. It argues that if there is such uncertainty, it should be regarded as causing the buyer an unreasonable inconvenience under art. 4:204(1). Third, the PELS does not seem to properly reflect the consumer's interests in that most consumers prefer to have the absolute right of termination as against the commercial sellers who have a relatively stronger bargaining position. The reasons for that is that there is a big hurdle, i.e., a hierarchy of remedies, to be overcome by the consumer to battle with the commercial seller, and that unavoidable vagueness in defining a minor lack of conformity has been often used against the consumer, but in favour of the commercial seller with a strong bargaining position.

• 대한견주관절학회:학술대회논문집
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• 대한견주관절학회 2009년도 제17차 학술대회
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• pp.174-174
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• 2009

The acromioclavicular-hook-plate is one of the surgical treatments for distal clavicle fracture and traumatic acromioclavicular (AC) joint dislocation. Although this procedure can obtain rigid and accurate anatomical reduction of the AC joint, secondary widening of the hook-hole in the acromion is often seen during postoperative follow-up. This complication is owing to the high-degree of mobility of the AC joint. Therefore, it is important to evaluate the effect on these complications due to the position of the hook-hole. The purpose of the present study is to investigate three-dimensionally the effect due to the position of the hook-hole during arm abduction motion. We studied in vivo and three-dimensional kinematics of the normal shoulder joint with use of a markerless bone-registration technique. Magnetic resonance images of 14 shoulders of 7 healthy volunteers were acquired in 7 positions between $0^{\circ}$ and $180^{\circ}$ of abduction. We created three-dimensional computer models of the bones and the acromioclavicular-hook-plate. Based on the three-dimensional kinematics data, we simulated the widening of the hook-hole each different positioning of the hook-hole. The widths of the hook-holes almost linearly increased. And these widths significantly increased, when we put the hook-hole on the acromion from AC joint to 20 mm and 25 mm posterior position.

• Wind and Structures
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• 제12권4호
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• pp.349-381
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• 2009

Since 1998, several institutions have deployed mobile instrumented towers to collect research-grade meteorological data from landfalling tropical cyclones. This study examines the wind flow characteristics from seven landfalling tropical cyclones using data collected from eight individual mobile tower deployments which occurred from 1998-2005. Gust factor, turbulence intensity, and integral scale statistics are inspected relative to changing surface roughness, mean wind speed and storm-relative position. Radar data, acquired from the National Weather Service (NWS) Weather Surveillance Radar - 1988 Doppler (WSR-88D) network, are examined to explore potential relationships with respect to radar reflectivity and precipitation structure (convective versus stratiform). The results indicate tropical cyclone wind flow characteristics are strongly influenced by the surrounding surface roughness (i.e., exposure) at each observation site, but some secondary storm dependencies are also documented.

• 임상간호연구
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• 제20권3호
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• pp.348-358
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• 2014

Purpose: This was a descriptive correlation study to identify emergency room (ER) nurses' coping types and factors affecting compassion satisfaction (CS) and compassion fatigue. Methods: During March and April 2013, 170 questionnaires were distributed to ER nurses working in general hospitals in D and C regions. Data were analyzed using descriptive statistics, t-test, ANOVA, correlation analysis, and stepwise regression analysis. Results: Compassion fatigue was most strongly affected by emotional expression for burnout and by practical support pursuit for secondary traumatic stress. Positive coping, emotional expression, position, positive reinterpretation, and self-blame explained 42% of CS. Conclusion: Results indicate that nurses with moderate levels of career had high compassion fatigue and low compassion satisfaction. Thus these nurses need to be given an opportunity to achieve self-development and improve their ability as nurses; interventions that can reinforce positive coping strategies should be provided as personal coping strategies affect compassion fatigue and compassion satisfaction.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집E
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• pp.720-726
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• 2001

Two-dimensional, angle-resolved LDV(Laser Doppler Velocimetry) measurements of the turbulent rotating flow field in a confined cylinder have been performed. The configurations of interest are flows between a rotating upper disk with a rod attached by a disk or impeller(${\theta}= 90^{\circ},\;45^{\circ}$) and a stationary lower disk in a confined cylinder. The mean flow velocity as well as the turbulent intensity of the flow field have been measured. The results show that the flow is strongly dependent on the position of the impellers or the disk, negligibly affected by the Reynolds number in turbulent flow. It is observed that the mixing effect of the axial flow impeller(${\theta}= 45^{\circ}$) is better than that of the radial flow impeller(${\theta}= 90^{\circ}$) or a disk.