• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.556-562
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• 2013

The blueberry eco-friendly farming requires the soil condition of pH 4.2 ~ 5.2 and high in organic matters for stable growth. Most of soil types of blueberry-growing land in Korea, however, belongs to alkaline soils with low organic matter content. As a result, the eco-friendly blueberry growers use peat moss and sulfur powder heavily to improve the soil condition, but the guideline on the effective use of organic materials was not established yet. Therefore, this sturdy was performed to investigate the effect of increasing soil acidity and organic matters by using organic materials. Among 5 organic materials, the pH of soil was lowest in degradable sulfur + bentonite (pH 4.1) and followed by Peat moss+Chaff+Pine Needlesmixtures(pH 4.5), OrganicAcid +vinegar (pH 4.7), Sulfur powder (pH 4.8), Temperature response Elutioner (pH 5.2). The soil organic matter content were increased in the following order: Peat moss+Chaff+Pine Needlesmixtures (8.4%) > degradable sulfur + bentonite (7.8%) > Organic Acid + vinegar (7.2%) > Sulfur powder ${\fallingdotseq}$ Temperature response Elutioner (6.3%). Although different in the degree, all organic materials treated was recognized a good material for improving soil pH and organic matter content. The plant height and stem diameter of blueberry were no clear difference among 5 organic materials. Another study was carried out to investigate amending soils with organic matter by soil mulching with pine needles for soil surface management in blueberry organic cultivation. The effect of increasing the soil pH by pine needle mulching in blueberry eco-friendly farming was recognized in four test fields. Pine needle mulching for soil surface management in blueberry appeared several advantages, such as improving of soil pH and organic matter content. Therefore, pineneedle mulching in blueberry organic farming is considered as the most efficient means of mulching cultivation for amending soil pH, weed suppression and moisture conservation among mulching materials.

• Publications of The Korean Astronomical Society
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• v.29 no.1
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• pp.1-16
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• 2014

Sambok (三伏, Three Hottest Days) is the common designation of Chobok (初伏, Early Hot Day), Jungbok (中伏, Middle Hot Day), and Malbok (末伏, Late Hot Day), and widely known to be one of the Korean folk customs. Hence, Sambok is notated in Manseryeok (Ten Thousand-Year Almanac) and in the annual astronomical almanac published by Korea Astronomy and Space Science Institute. In this paper, we investigate the changes of Sambok in Korea based on various documents such as Joseonwangjosilok (朝鮮王朝實錄, Annals of the Joseon Dynasty), Jeungbo-Jakryeoksik (增補作曆式, The Supplement of Manual for Calendar Making), astronomical almanacs, and so forth. According to Jeungbo-Jakryeoksik preserved in Kyujanggak Institute for Korean Studies, Chobok and Jungbok are defined as the third and fourth Gyeongil (庚日, The Day Starting with the Seventh Heavenly Stems in Sexagenary Cycles Assigned to Each Day) after the summer solstice, respectively, and Malbok is the first Gyeongil after Ipchu (Enthronement of Autumn). However, if the summer solstice is Gyeongil, then the third Gyeongil counting from the solstice becomes Chobok. Malbok depends on the time of Ipchu. Ipchu itself becomes Malbok if the time of Ipchu is in the morning, or next Gyeongil becomes Malbok if it is the afternoon. On the other hand, Malbok is defined as Ipchu itself regardless of its time according to Chiljeongbobeob (七政步法, Calculating Method for Sun, Moon, and Five Planets), Chubocheobryeo (推步捷例, Quick Examples for Calendrical Calculations), and so on. To verify the methods used to determine Sambok, we examined the record in the extant almanacs during the period of 1392 to 2100 for which the summer solstice or Ipchu is Gyeongil. As a result, we found a periodicity that if the time of Ipchu is in the morning, in general, the time is in the afternoon after two years and then is back into in the morning after nineteen years, i.e., the 2 + 19 years periodicity. However, we found the 2 + 17 years periodicity in some years. We also found that the Chobok method of Jeungbo-Jakryeoksik has been used since 1712, the thirty-eighth reign of King Sukjong (肅宗). In addition, we supposed that Malbok had been determined by the method like Chubocheobryeo since either 1846, the twelfth reign of King Heonjong (憲宗), or 1867, the fourth reign of King Gojong (高宗). At present, these methods of Sambok are customarily used without any legal basis. We, therefore, think that this study will help conventionalize the method defining Sambok in the future.

• Journal of Wetlands Research
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• v.14 no.1
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• pp.75-87
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• 2012

Hyporheic zone is a region beneath and alongside a stream, river, or lake bed, where there is mixing of shallow groundwater and surfacewater. Hyporheic exchange controls a variety of physical, biogeochemical and thermal processes, and provides unique ecotones in a aquatic ecosystem. Field and experimental observations, and modeling studies indicate that hyporheic exchange is mainly in response to pressure gradients driven by the geomorphological features of stream beds. In the reach scale of a stream, pool-riffle structures dominate the exchange patterns. Flow over a pool-riffle sequence develops recirculation zones and stagnation points, and this flow structures make irregular pressure gradient which is driving force of the hyporheic exchange. In this study, 3 D hydro-dynamic model solves the Reynolds-averaged Navier-Stokes equations for the surface water and Darcy's Law and the continuity equation for ground water. The two sets of equations are coupled via the pressure distribution along the interface. Simulation results show that recirculation zones and stagnation points in the pool-riffle structures dominantly control the upwelling and downwelling patterns. With decrease of recirculation zones, length of donwelling zone formed in front of riffles is reduced and position of maximum downwelling point moves downward. The numerical simulation could successfully predict the behavior of hyporheic exchange and contribute the field study, river management and restoration.

• Journal of The Korean Association of Information Education
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• v.24 no.2
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• pp.177-188
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• 2020

The purpose of this study was to examine the relationship between techno-stress perceived by elementary school teachers and related variables in a flipped learning environment. To achieve the purpose, the following research question have been established: First, what is the difference between techno-stress perceived by elementary school teachers? Second, what is the difference between techno-stress related variables perceived by elementary school teachers? Third, how do the TPACK, teacher effectiveness, and school environment support, perceived by elementary school teachers, affect technostress? 207 teachers at elementary school responded on a questionnaire to measure their perceived techno-stress, TPACK, teacher efficacy, and school environment support. Data were analyzed with using independent two-sample t-test, one-way ANOVA, and multiple regression analysis. The results were as follows: First, the elementary school teachers working on a leading school perceived higher techno-overload and techno-complexity more than those in ordinary school. Second, the elementary school teachers showed differences in the perception of TPACK, teacher efficacy, and school environment support according to the teacher's career, and leading school. Third, the elementary schools teachers perceived in TK, TCK, TPACK, educational support, and technology have a positive affect with techno-stress. The results are significant in that they provided data for reducing techno-stress of elementary school teachers in a flipped learning environment.

• Journal of Haehwa Medicine
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• v.16 no.1
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• pp.41-59
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• 2007

From the study of prescription on low back pain, the following conclusions are obtained. 1. Among classified cause of low back pain, ShinHur(腎虛) lowback pain and its prescription was most mentioned. 2. Prescriptions such as ChungAWhan(靑娥丸), KookBangAnShinWhan(局方安腎丸) BoSooDan(補髓丹) BaekBaeWhan(百倍丸) DooChungWhan(杜沖丸) JangBonDan(壯本丹) NokKakWhan(鹿角丸) were used in ShinHur(腎虛) type low back pain. 3. Prescription such as TaekRanTang(澤蘭湯) JiRyongSan(地龍散) YoeShinSan(如神散) ShinKookJoo(神麴酒) SoeGuenSan(舒筋散) were used in JwaSumJilBak(閃挫跌撲) type low back pain. 4. Prescription such as ChangChulTang(蒼朮湯) JumTongTang(拈痛湯) ChulBuTang(朮附湯) YiChoChangBaekSan(二炒蒼栢散) were used in SeupYoel(濕熱) type low back pain. 5. Prescription such as ChunGoongYookGaeTang(川芎肉桂湯) GaMiSaMulTang(加味四物湯) PaHoelSanDongTang(破血散疼湯) JiRyongSan(地龍散) were used in UhHoel(瘀血) type low back pain. 6. Prescription such as (蒼術復煎散) (五積散) (摩腰丹) (滲濕湯) were used in HanSeup(寒濕) type low back pain. 7. Prescription such as GaMiYiJinTang(加味二陳湯) GongYeonDan(控涎丹) SaMoolTangHapYiJinTangGaMi(四物湯合二陳湯加味) were used in DamUem(痰飮) type low back pain. 8. Prescription such as OhJukSanGaMi(五積散加味) OhYakSoonGiSanGaMi(烏藥順氣散加味) GaMiYongHoSan(加味龍虎散) SoSokMyoungTang(小續命湯) were used in Poong(風) type low back pain. 9. Prescription such as (四物湯合二陳湯) (仰腰湯) were used in SikJuk(食積) type low back pain and (五積散) (煨腎散) (三花神祐丸) in Seup(濕) type low back pain. 10. Prescription such as ChilKiTang(七氣湯) ChimHyangGangKiTang(沈香降氣湯) ChoKiSan(調氣散) InSamSoonKiSan(人參順氣散) were used in Ki(氣) type low back pain.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.575-578
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• 2005

We report on a low-cost V-band wireless transceiver with no use of any local oscillator in the receiver block using a self-heterodyne architecture. V-band Microwave monolithic IC (MMIC) modules were developed to demonstrate the wireless transceiver using coplanar waveguide (CPW) and GaAs PHEMT technologies. The MMIC modules such as the MMIC low noise amplifier (LNA), medium power amplifier (MPA) and the up/down-mixer were installed in the transceiver system. To interface the MMIC chips with the component modules for the transceiver system, CPW-to-waveguide fin-line transition modules of WR-15 type were designed and fabricated. The fabricated LNA modules showed a $S_{21}$ gain of 8.4 dB and a noise figure of 5.6 dB at 58 GHz. The MPA modules exhibited a gain of 6.9 dB and a $P_1$ $_{dB}$ of 5.4 dBm at 58 GHz. The conversion losses of the up-mixer and the down-mixer module were 14.3 dB at a LO power of 15 dBm, and 19.7 dB at a LO power of 0 dBm, respectively. From the measurement of V-band wireless transceiver, a conversion gain of 0.2 dB and a P $_{1dB}$ of 5.2 dBm were obtained in the transmitter block. The receiver block showed a conversion gain of 2.1 dB and a P $_{1dB}$ of -18.6 dBm. The wireless transceiver system demonstrated a successful data transfer within a distance of 5 meters.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.11
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• pp.48-53
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• 2007

In this paper, a high LO-RF isolation W-band MIMIC single-balanced mixer was designed and fabricated using a branch line coupler and a ${\lambda}/4$ transmission line. The W-band MIMIC single-balanced mixer was designed using the $0.1\;{\mu}m$ InGaAs/InAlAs/GaAs Metamorphic HEMT diode. The fabricated MHEMT was obtained the cut-off frequency($f_T$) of 154 GHz and the maximum oscillation frequency($f_{max}$) of 454 GHz. The designed MIMIC single-balanced mixer was fabricated using $0.1\;{\mu}m$ MHEMT MIMIC process. From the measurement, the conversion loss of the single-balanced mixer was 12.8 dB at an LO power of 8.6 dBm. P1 dB(1 dB compression point) of input and output were 5 dBm and -8.9 dBm, respectively. The LO-RF isolations of single-balanced mixer was obtained 37.2 dB at 94 GHz. We obtained in this study a higher LO-RF isolation compared to some other balanced mixers in millimeter-wave frequencies.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.11
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• pp.45-54
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• 2008

In this paper, we use particle swarm optimization (PSO) to design a randomly excited and randomly spaced linear array with either the lowest side lobe level (SLL) or the narrowest beamwidth. The positions and the excitation amplitudes of the array elements are considered as variables to be controlled. The beam pattern is optimized by controlling the two variables simultaneously and randomly. The best beam patterns are obtained using PSO in the fitness function where performance is improved by the random assignment of weight coefficients to each angular sector of the beam Pattern. The weight coefficients and angles are obtained through several trial runs. Also, an extra term, ${\beta}{\ast}BW$, is added to the fitness function to account for the beamwidth as well as the SLL. Is produces the best result for the beam pattern with either the lowest SLL or the narrowest beamwidth. In the former case, the SLL and beamwidth are about -43dB and $32.2^{\circ}$, respectively, with only 10 elements. In the latter case, the SLL and beamwidth are about -26dB and $24.2^{\circ}$, respectively.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.6 no.1
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• pp.91-101
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• 2008

The purpose of this study was to investigate the effects of Inline-skating exercise on the static balance. Total 10 subjects with common were recruited from university for student in Kwangyang, and the Inline-skating exercise was conducted 3times at a week during 2 weeks. Balance test was measured by using Good Balance with overall index, NSEO(normal standing when eye open), NSEC(normal standing when eye close), OLREO(one leg right standing when eye open), OLREC(one leg right standing when eye close), OLLEO(one leg left standing when eye open), OLLEC(one leg left standing There was statistically significant difference of the balance ability of the left-right only between the before and the after exercise in the case of NSEO position. however, the statistically difference was not found in terms of the Mean X speed, Mean Y speed, Velocity moment between the before and the after exercise in the case of NSEC position. There was statistically significant difference of the balance ability of the Mean X speed, Mean Y speed between the before and the after exercise in the case of OLLEO and OLLEC position, however, the statistically difference was not found in terms of the Velocity moment between the before and the after exercise in this case. There was statistically significant difference of the balance ability of all the terms between the before and the after exercise in the case of OLREO. however, the statistically difference was not found in terms of the Mean Y speed only between the before and the after exercise in the case of OLREC. In this case, the statistically difference was found in terms of Velocity moment between the before and the after exercise. This study showed that Inline-skating exercise was effected on the improvement of the balance ability in normal peoples.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.20 no.3
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• pp.107-112
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• 2010

The Cu$(In_{1-x}Ga_x)Se_2$ is the absorber material for thin film solar cell with high absorption coefficient of $1{\times}10^5cm^{-1}$. In the case of CIGS, the movable energy band gap from $CuInSe_2$ (1.00 eV) to $CuGaSe_2$ (1.68 eV) can be acquired while controlling Ga contain ratio. Generally, the co-evaporator method have used for development and fabrication of the CIGS absorption layer. However, this method should need many steps and lengthy deposition time with high temperature. For these reasons, in this paper, a new growth method of CIGS layer was attempted to hydride vapor transport (HVT) method. The CIGS mixed-source material reacted for HCl gas in the source zone was deposited on the substrate after transporting to growth zone. c-plane $Al_2O_3$ and undoped GaN were used as substrates for growth. The characteristics of grown samples were measured from SEM and EDS.