The objective of this research was to determine the effects of harvesting frequency and fertilization levels on botanical composition, dry matter yield, and forage feed compositions of Alpine grassland at 800 m altitude. This research lasted for three years at National Alpine Agricultural Research Institute in Pyeongchang with two harvesting frequency schedules (two and three times annually) and two levels of fertilizer application (conventional level of fertilizer at 280-200-240 kg/ha and a lower level of fertilizer at 200-200-200 kg/ha for N, P2O5, and K2O). Mixture combinations with seeding rate (kg/ha) were as follows: Orchardgrass 18, Tall fescue 9, Timothy 8, Kentucky bluegrass 3, and Ladino Clover 2. The gramineae ratio ranged from 93.2 to 95.3%. Therefore, gramineae forage was considered as the dominant plant in this experiment. No significant (p>0.05) difference was observed in forage dry matter yield between the two harvesting frequency treatments (two times at 9.8 ton/ha and three times at 8.6 ton/ha). However, forage dry matter yield in the two times of harvesting frequency tended to be greater than that in the three times of harvesting frequency. Significantly (p<0.05) higher forage dry matter yield in the standard fertilization level group than the lower fertilization level group (9.8 ton/ha vs. 8.7 ton/ha) was observed. However, there was no significant (p>0.05) difference in forage crude protein concentration between the two harvesting frequency treatment groups, although the concentration in the group with three times of harvesting frequency tended to be higher. In contrast, crude fiber concentration in the group with two times of harvesting frequency tended to be higher, although the difference was not statistically significant (p>0.05). Crude protein, ether extract, crude fiber, and organic matter concentrations were not significantly (p>0.05) different between the two groups with different fertilization levels. Based on these results, it was concluded that the group with two times of harvesting frequency with conventional fertilization level might be proper for obtaining better forage productivity for Alpine grassland at 800 m altitude.

Acoustic surveys using a scientific echosounder and trawl surveys were concurrently carried out in between Geoje and Tongyeong of the South Sea by season. The anchovy schools were identified by trawling in each station and used for frequency response analysis. Frequency responses of anchovy schools by season and species composition ratio were examined using multi-frequencies (18, 38, 70, 120 and 200 kHz). The frequency response r(f), is one of the acoustic characteristics which means the volume back-scattering strength ratio between a reference frequency and other frequencies. In spring, the r(f) of anchovy schools decreased with increased frequency, with the exception of 120kHz. While, in winter, the r(f) continuously decreased inversely proportional to the increase in frequency. Frequency response of anchovy schools presented a distinctive difference between spring and winter, however it did not different in spife of different species composition ratios in schools.

PURPOSES : The objective of this study is to determine the optimal frequency of ground penetrating radar (GPR) testing for detecting the voids under the pavement. METHODS : In order to determine the optimal frequency of GPR testing for void detection, a full-scale test section was constructed to simulate the actual size of voids under the pavement. Voids of various sizes were created by inserting styrofoam at varying depths under the pavement. Subsequently, 250-, 500-, and 800-MHz ground-coupled GPR testing was conducted in the test section and the resulting GPR signals were recorded. The change in the amplitude of these signals was evaluated by varying the GPR frequency, void size, and void depth. The optimum frequency was determined from the amplitude of the signals. RESULTS: The capacity of GPR to detect voids under the pavement was evaluated by using three different ground-coupled GPR frequencies. In the case of the B-scan GPR data, a parabolic shape occurred in the vicinity of the voids. The maximum GPR amplitude in the A-scan data was used to quantitatively determine the void-detection capacity. CONCLUSIONS: The 250-MHz GPR testing enabled the detection of 10 out of 12 simulated voids, whereas the 500-MHz testing allowed the detection of only five. Furthermore, the amplitude of GPR detection associated with 250-MHz testing is significantly higher than that of 500-MHz testing. This indicates that 250-MHz GPR testing is well-suited for the detection of voids located at depths ranging from 0.5~2.0 m. Testing at frequencies lower than 250 MHz is recommended for void detection at depths greater than 2 m.

In this study, we compared diet related attributes such as food taste preference, food consumption frequency and nutrition intake between elderly residents in their 80’s of areas in Jeollanam-do that are well known for longevity and those of a part of Seoul. Structured in-depth interviews were conducted by trained interviewers on 125 consented subjects (67 Jeonnam and 58 Seoul). Differences of groups were tested using Chi-square tests for nominal or ordinal data and t-tests and ANOVA tests for ratio data. The elderly from Jeonnam tended to sleep longer, express emotion more freely, and interact with others more often than those from Seoul. The elderly tended to prefer sweet or salty tastes, which might be highly related to serious health problems. The most frequently consumed foods were napa cabbage kimchi (2.19 times/day) and multigrain rice (1.99 times/day). Elderly from Jeonnam tended to consume garlic, milk, beans and roasted barley/corn teas less often; whereas, they consumed porridge, dried radish greens, potato, fermented fish, dried fish, pork rib, pork belly, soybean paste soup, soybean paste/Ssamjang, other kimchis, pickled vegetables, snacks, cookies, and green/black teas more often than elderly residents from Seoul. Differences in nutrition intake between the regions were greater than differences between the perceived levels of household economic status. NAR and INQ for folate were lower among elderly from Jeonnam than those from Seoul, while those for protein, vitamin C, niacin, vitamin B6 were higher. The study results indicated that elderly from Jeonnam engaged in a more diverse diet than the elderly from Seoul.

본 논문에서는 전동기 구동장치를 선정하여 리액터 용량 및 종류, 부하의 크기에 따라 고조파 왜형률 변화추이를 검토하여 선박 및 해양플랜트에 적용 가능한 최적의 용량선정 근거를 마련하였다. AC라인 리액터와 DC링크 리액터는 가변주파수 구동장치 입력전류의 고조파를 크게 저감시키는 역할을 하며, 동일한 효과를 얻기 위한 DC링크 리액터의 인덕턴스가 AC라인 리액터 인덕턴스의 약 1.7배가 되어야 한다는 것을 시뮬레이션을 통하여 고찰하였다. 소프터웨어 PSIM을 활용하여 각 상황에 따른 전류 고조파 왜형률을 분석하였다.

Active Galactic Nuclei (AGN) with bright radio jets oer the opportunity to study the structure of and physical conditions in relativistic out ows. For such studies, multi-frequency polarimetric very long baseline interferometric (VLBI) observations are important as they directly probe particle densities, magnetic eld geometries, and several other parameters. We present results from rst-epoch data obtained by the Korean VLBI Network (KVN) within the frame of the Plasma Physics of Active Galactic Nuclei (PAGaN) project. We observed seven radio-bright nearby AGN at frequencies of 22, 43, 86, and 129 GHz in dual polarization mode. Our observations constrain apparent brightness temperatures of jet components and radio cores in our sample to > 108:01 K and > 109:86 K, respectively. Degrees of linear polarization mL are relatively low overall: less than 10%. This indicates suppression of polarization by strong turbulence in the jets. We found an exceptionally high degree of polarization in a jet component of BL Lac at 43 GHz, with mL  40%. Assuming a transverse shock front propagating downstream along the jet, the shock front being almost parallel to the line of sight can explain the high degree of polarization.

We present results of long-term multi-wavelength polarization observations of the powerful blazar 3C 279 after its -ray flare on 2013 December 20. We followed up this flare with single-dish polarization observations using two 21-m telescopes of the Korean VLBI Network. Observations carried out weekly from 2013 December 25 to 2015 January 11, at 22 GHz, 43 GHz, 86 GHz simultaneously, as part of the Monitoring Of GAmma-ray Bright AGN (MOGABA) program. We measured 3C 279 total flux densities of 22–34 Jy at 22 GHz, 15–28 Jy (43 GHz), and 10–21 Jy (86 GHz), showing mild variability of ≤ 50% over the period of our observations. The spectral index between 22 GHz and 86 GHz ranged from −0.13 to −0.36. Linear polarization angles were 27◦–38◦, 30◦–42◦, and 33◦–50◦ at 22 GHz, 43 GHz, and 86 GHz, respectively. The degree of linear polarization was in the range of 6–12%, and slightly decreased with time at all frequencies. We investigated Faraday rotation and depolarization of the polarized emission at 22–86 GHz, and found Faraday rotation measures (RM) of −300 to −1200 rad m−2 between 22 GHz and 43 GHz, and −800 to −5100 rad m−2 between 43 GHz and 86 GHz. The RM values follow a power law with a mean power law index a of 2.2, implying that the polarized emission at these frequencies travels through a Faraday screen in or near the jet. We conclude that the regions emitting polarized radio emission may be different from the region responsible for the 2013 December -ray flare and are maintained by the dominant magnetic field perpendicular to the direction of the radio jet at milliarcsecond scales.

The Interferometric Monitoring of Gamma–ray Bright Active galactic nuclei (iMOGABA) program provides not only simultaneous multifrequency observations of bright gamma–ray detected active galactic nuclei (AGN), but also covers the highest Very Large Baseline Interferometry (VLBI) frequencies ever being systematically monitored, up to 129 GHz. However, observation and imaging of weak sources at the highest observed frequencies is very challenging. In the second paper in this series, we evaluate the viability of the frequency phase transfer technique to iMOGABA in order to obtain larger coherence time at the higher frequencies of this program (86 and 129 GHz) and image additional sources that were not detected using standard techniques. We find that this method is applicable to the iMOGABA program even under non–optimal weather conditions.

This study was conducted on wine consumers to explore their behavioral characteristics concerning their drinking frequency of wine, wine selection factors, and difficulties in selecting wines. Data were collected during February 19th 2014 to April 20th 2014. Respondents were students who were taking classes about wine at a University located in the Gyeonggido area. Prior to the analysis, wine consumers were classified based on frequency of consumption: those who consumed wine less than once a month were classified as “Tell me consumers”, whereas those who consumed wine once or more a month were classified as “Engage me consumers.” The wine selection factors of the two groups were as follows: ‘label aspect’, ‘taste and aroma’, ‘use purpose’, and ‘price and recommendation’. Regarding ‘label aspect’ and ‘use purpose’, there were significant differences between the two groups. Regarding difficulties in selecting wines, “Tell me consumers” mentioned the following: ‘experience’, ‘price’, and ‘food pairing’. “Engage me consumers” mentioned the following: ‘ability to identify new wines’ and ‘tastes of others who drink with or oneself’. Classifying domestic wine consumers and their behavioral features of drinking frequency of wine can be used for market segmentation of wine consumers.

여성은 연령과 사회경제적 위치에 따라 건강문제에 상당 한 차이가 있어 여성건강증진을 위해 지속적 노력을 기울여 야 한다. 숲은 현대인의 스트레스를 해소하고 면역력을 높 여주는 더할 나위 없는 자연환경이다. 숲 체험 경험이 있는 경우와 경험횟수가 많은 경우에 중년여성이 지각하는 삶의 만족도, 행복감, 희망수준이 유의하게 높은 것으로 나타났 다. 숲을 자주 이용할 수 있는 직장인들은 그렇지 못한 직장 인들에 비해 직무에 대한 스트레스가 낮은 것으로 나타났다. 이에 본 연구는 평소 숲 방문 빈도가 성인 여성의 스트레스 수준에 있어 어떤 차이를 가져오는지를 살펴보고자 했다. 20대 이상의 성인 여성 407명을 연구 대상으로 선정하여 숲 방문 빈도(숲 방문 빈도가 월 1회 이상인 144명은 “높음” 으로, 분기별 1회 이하인 263명은 “낮음”으로 분류)에 따라 구분한 두 집단 사이의 사회·심리적 스트레스(SF-PWI)와 스 트레스 반응(SRI)을 독립 t검증으로 비교하였다. 연구 결과 숲 방문 빈도에 따라 구분한 두 집단 사이의 사회·심리적 스트레스(SF-PWI)와 스트레스 반응(SRI)을 비교한 결과, 연령, 교육수준, 결혼 상태, 직업 등의 인구학 적 특성에서 통계적으로 유의한 차이를 발견하였다. 특히 50대 이상, 고학력의 전문․연구직, 교직, 400만원 이상이 각 각 숲 방문 빈도가 높게 나타났다. 우리나라 인구의 고학력 화와 고학력에 따른 경제활동 우위, 그로부터 얻어지는 경 제적 안정에서 원인을 찾을 수 있을 것이다. 고학력 전문직 에 종사하는 여성은 건강과 스트레스 감소를 위해 숲을 자 주 방문한다는 것으로 해석할 수 있다. 또한, 고졸, 100만원 미만의 저학력, 저소득의 무직·기타의 여성도 숲을 자주 방 문하는 것으로 나타났다. 이는 소득이 적을수록 비용이 상 대적으로 적게 드는 산책과 같은 활동을 선호하는 것으로 사료된다. 두 집단의 스트레스 수준을 분석한 결과 숲 방문을 통한 산림환경이용 빈도에 따른 차이를 확인할 수 있었다. 사회· 심리적 척도(SF-PWI), 스트레스 반응척도(SRI)에서 숲 방 문을 통해 산림환경 이용 빈도가 높은 집단이 사회·심리적 스트레스와 우울, 피로 등의 스트레스 반응이 적은 것으로 나타났다. 본 연구는 ‘숲 방문 빈도’만으로 숲 방문을 통한 효과를 측정했기 때문에 대상자들이 숲을 ‘어떻게 이용하는지’에 대해서는 확인할 수 없었다. 추후 연구에서는 스트레스 완 화에 더 효과적인 숲 이용방식과 산림치유 프로그램에 대한 후속연구가 필요하다. 본 연구 결과는 숲을 평소에 적극적으로 방문하는 것이 성인 여성들로 하여금 스트레스를 좀 더 적게 받게 하고, 피로도와 우울도를 낮추는데 도움이 됨을 시사한다. 본 연 구를 계기로 차후 성인 여성의 산림환경 이용방식에 대한 다각화된 조사와 함께 숲 방문 빈도가 비교적 활발한 직업 의 교사, 주부, 회사원 등의 직업에 대한 검증, 숲 방문 빈도 를 통한 산림환경이 일반 성인의 스트레스를 감소시키는데 어떻게 영향을 미치는지에 대한 연구가 이루어지기를 기대 한다.

In this proceedings, preliminary results of the KVN Source-Frequency Phase-Referencing (SFPR) observation of 3C 66A and 3C 66B are presented. The motivation of this work is to measure the core-shift of these 2 sources and study the temporal evolution of the jet opacity. Two more sources were observed as secondary reference calibrators and each source was observed at 22, 43, and 86 GHz simultaneously. Our preliminary results show that after using the observations at the lower frequency to calibrate those at the higher frequency of the same source, the residual visibility phases for each source at the higher frequencies became more aligned, and the coherence time became much longer; also, the residual phases for different sources, within 10 degrees angular separations, follow similar trends. After reference to the nearby calibrator, the SFPRed maps were obtained as well as the astrometric measurements, i.e. the combined coreshift. The measurements were found to be affected by structural blending effects because of the large beamsize of KVN, but this can be corrected with higher resolution maps (e.g. KAVA maps).

We present the results from analysis of the Hilbert-Huang transform (HHT) for the 4 Hz quasi-periodic oscillations (QPO) around the black hole X-ray binary XTE J1550-564. The resultant Hilbert spectra demonstrate that the QPO is composed of a series of intermittent signals appearing occasionally. From the analysis of the HHT, we further found the distribution of the lifetimes for the intermittent oscillations and the distribution for the time intervals with no significant signal (the break time). The mean lifetime is 1.45 s and 90% of the oscillation segments have lifetimes less than 3.1 s whereas the mean break time is 0.42 s and 90% of break times are less than 0.73 s. We conclude that the intermittent feature of the QPO could be explained by the Lense-Thirring precession model and rules out interpretations of continual frequency modulation.