We investigate the properties of AGB and post-AGB (PAGB) stars, planetary nebulae, and young stellar objects (YSOs) in our Galaxy through an analysis of observational data covering visual and infrared (IR) wavelengths. Utilizing datasets from IRAS, 2MASS, AllWISE, Gaia DR3, and the SIMBAD object database, we perform an in-depth comparison between observational data and theoretical models. For this comparison, we present various color-magnitude diagrams (CMDs) in visual and IR bands, as well as IR two-color diagrams (2CDs). Our results demonstrate that the CMDs, incorporating the latest distance and extinction data from Gaia DR3 for a majority of sample stars, are effective in distinguishing different classes of stars. To improve the precision of our analysis, we apply theoretical radiative transfer models for dust shells around AGB and PAGB stars. A thorough comparison of the theoretical models with observations across various IR 2CDs and CMDs shows a significant agreement. We find that AGB and PAGB stars are among the brightest classes in visual and IR bands. Furthermore, most YSOs are clearly distinguishable from AGB stars on various IR CMDs, exhibiting fainter absolute magnitudes in IR bands.

We present various infrared two-color diagrams (2CDs) using WISE data for asymptotic giant branch (AGB) stars and Planetary Nebulae (PNe) and investigate possible evolutionary tracks. We use the sample of 5036 AGB stars, 660 post-AGB stars, and 2748 PNe in our Galaxy. For each object, we cross-identify the IRAS, AKARI, WISE, and 2MASS counterparts. To investigate the spectral evolution from AGB stars to PNe, we compare the theoretical model tracks of AGB stars and post-AGB stars with the observations on the IR 2CDs. We find that the theoretical dust shell model tracks can roughly explain the observations of AGB stars, post-AGB stars, and PNe on the various IR 2CDs. WISE data are useful in studying the evolution of AGB stars and PNe, especially for dim objects. We find that most observed color indices generally increase during the evolution from AGB stars to PNe. We also find that Fe0.9Mg0.1O dust is useful to fit the observed WISE W3-W4 colors for O-rich AGB stars with thin dust shells.

고추 유래 유전자(CaMsrB2-23)를 도입하여 내건성을 갖도록 형질전환된 가뭄저항성벼(Agb0103)에 대한 식품안전성 평가를 위해 가뭄저항성벼 종실(현미)의 일반성분, 지방산, 아미노산, 무기질, 비타민 함량 등 영양성분과 항영양소를 분석하였다. 벼는 수원과 군위 2개 지역에서 2013년에 재배하였으며, 가뭄저항성벼와 일미벼 현미는 조단백질, 조지방, 조회분, 조섬유 등 일반성분 함량에 유의적인 차이가 없었으며 지방산 조성 및 아미노산 함량이 서로 유사하였다. Agb0103과 일미벼 현미의 무기질 함량은 Na 함량에서 차이가 있었으나 Na를 제외하고 모든 무기질 함량이 유사하였으며 OECD 기준 범위 내에 있었다. 대체적으로 수원에서 재배한 벼 현미의 무기질 함량이 약간 높게 나타나 재배지역간의 환경적 차이가 무기질의 함량에 영향을 주는 것으로 나타났다. 두 지역에서 재배한 Agb0103과 일미벼 현미의 비타민 함량은 유의적인 차이가 없었으나 비타민 B 함량이 OECD 자료 범위보다 낮게 나타났다. 가뭄저항성벼(Agb0103)의 사료용 평가를 위해 지상부(유숙기 잎줄기와 볏짚)에 대한 영양성분을 분석한 결과 조단백질, 조지방, 조회분, 조섬유, ADF, NDF, Ca, P의 함량에서 Agb0103과 모품종벼 간의 차이는 없는 것으로 분석되었다. 따라서 본 연구를 통해 조사한 가뭄저항성벼(Agb0103)는 모품종 대비 종실의 주요 영양성분과 항영양소 뿐만 아니라 벼 지상부의 성분분석 비교 결과 실질적 동등성을 확인 할 수 있었다.

We present a new catalog of AGB stars based on infrared two-color diagrams (2CDs) and known properties of the pulsations and spectra. We exclude some misclassified objects from previous catalogs. We identify color areas in two IR 2CDs where most O-rich and C-rich objects listed in previous catalogs of AGB stars are found. By collecting new objects in these color selection areas in the two IR 2CDs, we find candidate objects for AGB stars. By using the color selection method, we identify 3996 new objects in the O-rich areas, 1487 new objects in the C-rich areas, and 295 new objects in the overlap areas of the two 2CDs simultaneously. We have found that 470 O-rich and 9 C-rich objects are Mira variables with positive spectral identification and they are newly identified AGB stars. We present a new catalog of 3828 O-rich AGB stars and 1168 C-rich AGB stars excluding misclassified objects and adding newly identified objects.

We present the results of simultaneous monitoring observations of H2O 61,6–52,3 (22GHz) and SiO J=1–0, 2–1, 3–2 maser lines (43, 86, 129GHz) toward five post-AGB (candidate) stars, using the 21-m single-dish telescopes of the Korean VLBI Network. Depending on the target objects, 7 – 11 epochs of data were obtained. We detected both H2O and SiO maser lines from four sources: OH16.1−0.3, OH38.10−0.13, OH65.5+1.3, and IRAS 19312+1950. We could not detect H2O maser emission toward OH13.1+5.1 between the late OH/IR and post-AGB stage. The detected H2O masers show typical double- peaked line profiles. The SiO masers from four sources, except IRAS 19312+1950, show the peaks around the stellar velocity as a single peak, whereas the SiO masers from IRAS 19312+1950 occur above the red peak of the H2O maser. We analyzed the properties of detected maser lines, and investigated their evolutionary state through comparison with the full widths at zero power. The distribution of observed target sources was also investigated in the IRAS two-color diagram in relation with the evolutionary stage of post-AGB stars. From our analyses, the evolutionary sequence of observed sources is suggested as OH65.5+1.3! OH13.1+5.1! OH16.1−0.3! OH38.10−0.13, except for IRAS 19312+1950. In addition, OH13.1+5.1 from which the H2O maser has not been detected is suggested to be on the gateway toward the post-AGB stage. With respect to the enigmatic object, IRAS 19312+1950, we could not clearly figure out its nature. To properly explain the unusual phenomena of SiO and H2O masers, it is essential to establish the relative locations and spatial distributions of two masers using VLBI technique. We also include the 1.2 – 160 μm spectral energy distribution using photometric data from the following surveys: 2MASS, WISE, MSX, IRAS, and AKARI (IRC and FIS). In addition, from the IRAS LRS spectra, we found that the depth of silicate absorption features shows significant variations depending on the evolutionary sequence, associated with the termination of AGB phase mass-loss.

We investigate optical properties of amorphous alumina (Al2O3) dust grains in the envelopes around O-rich asymptotic giant branch (AGB) stars using laboratory measured optical data. We derive the optical constants of amorphous alumina over a wide wavelength range that satisfy the Kramers- Kronig relation and reproduce the laboratory data. Using the amorphous alumina and silicate dust, we compare the radiative transfer model results with the observed spectral energy distributions. Comparing the theoretical models with observations on various IR two-color diagrams for a large sample of O-rich AGB stars, we find that the amorphous alumina dust (about 10-40%) mixed with amorphous silicate better models the observed points for the O-rich AGB stars with thin dust envelopes.

농업환경의 급속한 변화에 의한 농업생명공학과 GM작물의증가는 인간의 건강과 자연환경에 대한 깊은 관심을 초래하였고, 이에 대한 환경위험 여부를 확인하기 위해 GM작물의 안전성 평가가 필수 요소가 되었다. 이에 본 연구는 가뭄저항성(Agb0103)벼와 일미벼의 잉어(Carp, Cyprinus carpio)와 미꾸리(Loach, Misgurnus anguillicaudatus)에 대한 급성독성시험을 평가한 결과 48시간과 96시간의 LC50은 1,000 mg/L이상으로 분석되었다. 48시간과 96시간의 무영향농도는 1,000 mg/L이었다. 잉어와 미꾸리의 급성독성 시험기간 중 가뭄저항성(Agb0103)벼와 일미벼 간의 체중, 전장, 수온, DO 및 pH에대한 유의적인 차이는 없었다.

The main site of dust formation is believed to be the cool envelopes around AGB stars. Nearly all AGB stars can be identified as long-period variables (LPVs) with large amplitude pulsation. Shock waves produce by the strong pulsation and radiation pressure on newly formed dust grains drive dusty stellar winds with high mass-loss rates. IR observations of AGB stars identify various dust species in different physical conditions. Radio observations of gas phase materials are helpful to understand the overall properties of the stellar winds. In this paper, we review (i) classification of AGB stars; (ii) IR two-color diagrams of AGB stars; (iii) pulsation of AGB stars; (iv) dust around AGB stars including dusty stellar winds; (v) dust envelopes around AGB stars; (vi) mass-loss and evolution of AGB stars; and (vii) contribution of AGB dust to galactic environments. We discuss various observational evidences and their theoretical interpretations.

약관규제법은 사업자에 의하여 일방적으로 작성된 계약내용에 의하여 고객이 부당하게 불리하게 취급당하는 것을 방지하기 위한 목적으로 제정되었다. 따라서 이러한 목적을 실현하기 위하여 모든 약관규제법의 규정을 해석해야 하며, 약관의 개념도 이러한 목적 하에서 고찰해야 한다. 결국 약관의 개념은 사업자가 계약의 내용을 정하기 위하여 사전에 마련하기만 하면 충족되는 매우 넓은 개념으로 이해하여야 한다. 그리고 그 존재는 고객이 증명해야 하지만, 전문적인 시장참가자에 의하여 다수 계약의 체결을 위하여 마련한 것으로 보이면 사실상 약관으로 추정된다. 따라서 오히려 사업자가 반증을 통하여 약관이 아니라는 점 또는 개별적인 흥정에 의한 개별약정이라는 점을 증명해야 한다.약관의 개념은 되도록 넓게 해석되어야 하고 그 증명도 쉽게 인정되어야 하며, 그 존재를 부정하려고 하면 사업자에 의한 증명이 엄격히 이루어지도록 해야 할 것이다. 이러한 개념의 해석 및 증명을 요구하는 것이 약관규제법의 입법취지를 최대한 발휘하도록 하게 하는 것이다.

We investigate the properties of OH, SiO, and H2O maser emission in O-rich AGB stars. We use a sample of 3373 objects, which is an updated version of the list of O-rich AGB stars presented in Suh & Kwon (2011). We divide the 3373 O-rich AGB stars into four different groups based on the maser emission: OH maser sources (1533), SiO sources (1627), H2O sources (452), and sources with no maser (610). To understand the nature of the maser sources, we present various infrared two-color diagrams (2CDs) using IRAS, 2MASS, and AKARI data. For each group, we compare the positions on various infrared 2CDs with theoretical models. We ¯nd that the OH maser sources generally show larger color indices and larger dust optical depths than SiO or H2O sources. We suggest that the differences of the color indices for different maser sources are due to different mass-loss rates and dust formation processes.

We make a new catalog of AGB stars in our Galaxy from the sources listed in the Infrared Astronomical Satellite (IRAS) point source catalog (PSC) compiling the lists of previous works with verifying processes. We verify the class identification of AGB stars into oxygen-rich and carbon-rich stars using the information from recent investigations. For the large sample of AGB stars, we present infrared two-color diagrams from the observations at near infrared bands and IRAS PSC. On the two-color diagrams, we plot the tracks of theoretical radiative transfer model results with increasing dust shell optical depths. Comparing the observations with the theoretical tracks, we discuss the meaning of the infrared two-color diagrams.

We investigate the spectral energy distributions (SEDs) of low mass-loss rate O-rich asymptotic giant branch (AGB) stars using the infrared observational data including the Infrared Space Observatory (ISO) data. Comparing the results of detailed radiative transfer model calculations with observations, we find that the dust formation temperature is much lower than 1000 K for standard dust shell models. We find that the superwind model with a density-enhanced region can be a possible alternative dust shell model for LMOA stars.