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검색결과 3,693건 처리시간 0.045초

Crystal Structure and Physical Property of Tetragonal-like Epitaxial Bismuth Ferrites Film

  • Nam, Joong-Hee;Biegalski, Michael;Christen, Hans M.;Kim, Byung-Ik
    • 한국자기학회:학술대회 개요집
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    • 한국자기학회 2011년도 임시총회 및 하계학술연구발표회
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    • pp.7-8
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    • 2011
  • Basically, the lattice mismatch between film and substrate can make those BiFeO3(BFO) films distorted with strain structure. BFO phase can be stabilized on LaAlO3(LAO) represents the example of a multiferroic with giant axial ratio. Its crystal structure is not strictly tetragonal, but tetragonal with a slight monoclinic distortion and related to the rotation of the oxygen octahedra. In this study, we show that phases with a tetragonal-like epitaxial BFO films can indeed be ferroelectric and also can be stabilized via epitaxial growth onto LAO. Recent reports on epitaxial BFO films show that the crystal structure changes from nearly rhombohedral ("R-like") to nearly tetragonal("T-like") at strains exceeding approximately -4.5%, with the "T-like" structure being characterized by a highly enhanced c/a ratio. While both the "R-like" and the "T-like" phases are monoclinic, our detailed x-ray diffraction results reveal asymmetry change from MA and MC type, respectively. By applying additional strain or by modifying the unit cell volume of the film by substituting Ba for Bi, the monoclinic distortion in the "T-like" MC phase is reduced, i.e. the system approaches a true tetragonal symmetry. There are two different M-H loops for $Bi_{1-x}Ba_xFeO_{3-{\delta}}$(BBFO) and BFO films on SrTiO3(STO) & LAO substrates. Along with the ferroelectric characterization, these magnetic data indicate that the BFO phase stabilized on LAO represents the first example of a multiferroic with giant axial ratio. However, there is a significant difference between this phase and other predicted ferroelectrics with a giant axial ratio: its crystal structure is not strictly tetragonal, but tetragonal with a slight monoclinic distortion. Therefore, in going from bulk to highly-strained films, a phase sequence of rhombohedral(R)-to-monoclinic ["R-like" MA-to-monoclinic, "T-like" MC-to-tetragonal (T)] is observed. This sequence is otherwise seen only near morphotropic phase boundaries in lead-based solid-solution perovskites (i.e. near a compositionally induced phase instability), where it can be controlled by electric field, temperature, or composition. Our results show that this evolution can occur in a lead-free, stoichiometric material and can be induced by stress alone. Those major results are summarized as follows ; 1) Ba-doping increases the unit cell volume, 2) BBFO on LAO can be fully strained up to x=0.08 as a strain limit (Fig. 1), 3) P(E) & M(H) properties can be tuned by the variation of composition, strain, and film thickness.

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달맞이꽃 발효액 첨가 양념 돈육의 품질 특성 (Quality Characteristics of Seasoned Pork with Fermented Oenothera biennis Juice)

  • 안유복;박나영;이신호
    • 한국식품영양과학회지
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    • 제45권7호
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    • pp.1010-1016
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    • 2016
  • 달맞이꽃 발효액을 식품소재로써 활용 가능성을 모색하기 위해 달맞이꽃 발효액 5%(5-SP, seasoned pork), 10%(10-SP), 15%(15-SP)를 첨가한 소스로 제조한 양념 돈육을 $10^{\circ}C$에서 저장하면서 품질 특성을 비교하였다. pH는 저장초기 6.09에서 대조구와 5-SP, 10-SP, 15-SP 등 모든 시험구에서 저장 6일 이후부터 감소하여 저장 15일째 pH 4.83~4.90 범위를 나타내었다. 산도는 처리구별 뚜렷한 차이는 없었으나 모든 처리구에서 저장 6일 이후부터 뚜렷하게 증가하였다. 총균수는 저장 9일째 대조구 $10^7CFU/g$보다 5-SP와 10-SP는 $10^5CFU/g$을 나타내어 약 1~2 log cycle 억제되는 경향을 나타내었다. 휘발성 염기태질소 함량은 저장 초기 7.70 mg%에서 저장 12일째에 대조구 17.65 mg%, 5-SP 12.61 mg%, 10-SP 12.62 mg%를 나타내었다. 가열 감량은 저장 15일째 대조구 44.98%, 5-SP, 10-SP는 각각 37.66%, 38.59%로 달맞이꽃 발효액 첨가 소스로 처리한 양념 돈육이 우수하였다. 적색도는 달맞이꽃 발효액 첨가 소스로 제조한 양념 돈육이 대조구에 비해 유의적으로 높았으며, 저장기간 동안 감소하였다(P<0.05). 관능검사 결과 맛, 색, 풍미, 종합적 기호도에서 5-SP가 각각 4.00, 4.00, 3.91, 4.09로 가장 높은 기호도를 나타내었다.

무선 LAN에서 이상 및 페이딩 채널 환경의 DCF 처리율 비교 분석 (A DCF Throughput Analysis of the Ideal and Fading Channel in the Wireless LAN)

  • 이용식;이하철;이병호
    • 한국전자파학회논문지
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    • 제19권7호
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    • pp.741-753
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    • 2008
  • 본 논문에서는 IEEE 802.11a 무선 LAN의 이상적인 채널 환경과 페이딩 채널 환경에서 패킷의 페이로드 크기에 따른 MAC(Medium Access Control) 계층의 CSMA/CA(Carrier Sense Multiple Access/Collision Avoidance) 기반 DCF(Distributed Coordination Function) 처리율을 비교 분석하였다. 이상적인 채널 환경인 경우 에러가 없는 채널을 의미하고, 임의의 전송 주기 동안 패킷을 전송하는 단말이 1개만 존재하며, 다른 단말은 패킷을 수신한 후 응답한다고 가정한다. 페이딩 채널 환경인 경우 채널상에서 비트 에러는 랜덤하게 발생되며, 단말수 n은 고정되고, 각각의 단말은 항상 전송 패킷을 가지고 있는 포화 조건(saturation condition) 하에서 동작된다고 한다. IEEE 802.11a 무선 LAN의 처리율을 구하기 위해 기존 연구에서는 주로 이상적인 채널 환경을 가정하여 최대 처리율을 구하였는데, 실제의 통신 환경은 페이딩 패널이므로 본 연구에서는 $E_b/N_o$를 25 dB, 부 채널에서 직접 수신된 신호와 산란되어 수신된 신호의 전력비 $\xi$는 복합 Rayleigh/Ricean 페이딩을 고려하여 6으로 정하였다. 분석 결과, 이상적인 채널 환경에서의 처리율에 비교하여 페이딩 채널 환경에서의 처리율이 모든 페이로드 크기에서 더 작아진다는 것을 알 수 있으며, 전송율이 증가할수록 이상적인 채널의 최대 처리율에 대한 페이딩 채널의 포화 처리율의 감소 비율이 더 커진다는 것도 알 수 있다.

함초 분말 첨가가 식빵의 품질 특성에 미치는 영향 (Effect of Salicornia herbacea L. Powder on the Quality Characteristics of Bread)

  • 배종윤;박나영;이신호
    • 한국식품영양과학회지
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    • 제37권9호
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    • pp.1196-1201
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    • 2008
  • 함초 분말을 이용한 식빵의 품질에 대해 검토하였다. 함초분말 첨가에 의해 식빵의 조섬유, 칼슘 그리고 철분함량이 뚜렷하게 증가하였으며, pH는 함초 첨가 식빵이 대조구에 비해 높았다. 함초 분말을 0.6%에서 2.4%까지 첨가한 식빵의 염도는 대조구와 유의적인 차이를 나타내지 않았다. 함초분말 첨가 식빵의 표면 색도는 대조구에 비해 L값과 b값은 감소하였으나 a값은 증가하였고, 빵 내부의 색도는 함초 분말 첨가량 1.8%까지는 대조구와 유의적인 차이를 나타내지 않았다. 함초를 첨가한 식빵의 조직감(hardness, spinginess, chewiness, cohesiveness)은 대조구보다 높았으며, 함초 첨가량이 증가할수록 증가하였다. 식빵의 전자공여능을 조사한 결과, 함초 분말 0.6, 1.2 1.8, 2.4 및 6.0% 첨가구 각각 30.42, 33.91, 39.51, 41.17 및 63.82%로 대조구의 27.95%보다 높았으며, 함초 첨가량이 증가할수록 식빵의 지방산패 억제 활성은 증가하였고 폴리페놀 함량도 증가하였다.

pN2 이상인 조기위암 환자의 수술 전과 수술 중의 평가 (What is the Prognosis for Early Gastric Cancer with pN Stage 2 or 3 at the Time of Pre-operation and Operation)

  • 김찬영;이세열;양두현
    • Journal of Gastric Cancer
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    • 제6권2호
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    • pp.114-119
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    • 2006
  • 목적: pN2 이상의 조기 위암환자들은 수술 전, 중에 병기 진행의 예측이 가능하였는지 아니면 전혀 예측하지 못한 채 낮은 병기를 기대하다가 병리조직검사의 결과를 보고서야 알게 되는지를 알고자 하였다. 대상과 방법: 1990년부터 2003년까지 본 연구기관에서 위암으로 위 절제술을 받은 1,430명 중 조기위암 환자는 552명(38.6%)이었고 이들 중 pN2, pN3 환자 8명을 대상으로 수술 전의 임상적 병기 예측과 수술 중의 수술자가 예측한 병기 예측을 병리조직검사의 결과와 비교하고 환자의 경과를 알아보았다. 결과: pN2와 pN3인 조기위암 환자들은 모든 연령층에 분포하였고 남자가 7명으로 여자보다 많았다. 수술 전 전산화단층촬영의 평가에서 T1의 평가는 25% (2/8)로 대체로 과평가되었고 N2 이상 평가는 50% (4/8)이었다. cTNM병기 Ia의 예측환자는 한 명으로 나머지 환자는 진행된 병기로 예측하였다. 수술 중의 T1의 평가는 57.1%(4/7), N2 이상 평가는 66.7% (4/6)이었고 sTNM병기 Ia로 평가한 환자는 2명으로 나머지 환자들은 진행된 병기의 예측이 가능하였다. 5년 이상 장기생존 환자는 단 1명이었고 이들 8명의 중앙 생존기간은 15개월$(95%\;Cl:\;0{\sim}35.5)$이었다. 결론: pN2 이상의 조기위암 환자들은 수술 전이나 중에 진행된 병기로 예측이 어느 정도 가능하였다. 그러나 전혀 예측할 수 없었던 환자도 있어서 보다 정확히 예측할 수 있는 방법의 연구가 필요하겠다.

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인터루킨-4를 발현하는 재조합 백시니아 바이러스에 의한 암성장의 억제 (Effective Antitumor Activity of a Recombinant Vaccinia Virus Expressing Murine Interleukin 4)

  • 윤기정;김영일;김선영
    • 대한바이러스학회지
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    • 제28권1호
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    • pp.71-78
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    • 1998
  • Vaccinia virus is the prototype orthopoxvirus that has been used as a vaccine strain for small pox. This virus has been used to express a variety of cellular and viral genes in mammalian cells at high levels. Interleukin-4 (IL-4) has been found to stimulate the proliferation of T cells and enhance the cytolytic activity of cytotoxic T lymphocytes. To test the immunotherapeutic potential of IL-4 delivered in vivo by poxvirus, a recombinant vaccinia virus expressing the murine IL-4 gene (RVVmIL-4) was constructed. A high level of IL-4 production was confirmed by infecting HeLa cells and measuring IL-4 in cell culture supernatant by ELISA. As a tumor model, two cell lines were used; the murine T leukemic line P388 and the murine breast cancer line TS/A. CDF1 mice were intraperitoneally inoculated with $1\;{\times}\;10^5$ cells of P388. Mice were injected at the same site with $5\;{\times}\;10^5\;PFU$ of recombinant vaccinia virus; first, 3 days after the injection of tumor cells and thereafter once every week for 3 weeks. Intraperitoneal injections of RVVmIL-4 significantly prolonged the survival time of mice inoculated with tumor cells. All mice injected with RVVmIL-4 remained alive for 30 days after the postinoculation of tumor cells, while 100% and 70% of the animals injected with saline or wild type vaccinia virus died, respectively. In another tumor model using TS/A, tumor was established by subcutaneously inoculating $2{\times}10^5$ tumor cells to BALB/c mice. After tumor formation was confirmed on day 4 in all mice, $5\;{\times}\;10^6\;PFU$ of RVVmIL-4 was inoculated subcutaneously three times, once every week for 3 weeks. The TS/A tumor was eradicated in two of the nine mice. Seven of the nine mice treated with RVVmIL-4 developed a tumor, but tumor growth was significantly delayed compared to those treated with saline or wild type vaccinia virus. These results indicate that recombinant vaccinia viruses may be used as a convenient tool for delivering immunomodulator genes to a variety of tumors.

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Association of Metastasis with Clinicopathological Data in Mexican Patients with Osteosarcoma, Giant Cell Tumor of Bone and Chondrosarcoma

  • Estrada-Villaseor, E;Escamilla-Uribe, R;De la Garza-Montano, P;Dominguez-Rubio, R;Martinez-Lopez, V;Avila-Luna, A;Alfaro-Rodriguez, A;Ruvalcaba-Paredes, EK;Garciadiego-Cazares, D;Bandala, C
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권17호
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    • pp.7689-7694
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    • 2015
  • Background: Bone tumors are neoplasias with a high overall mortality; one of the main factors that reduce survival is their high capacity to develop metastases. It has been reported that finding lung metastases at diagnosis of osteosarcoma (OS), chondrosarcoma (CS) and giant cell tumor of bone (GCTb) is quite common. In this study, we inquire the relationship of metastases caused by these tumors with different clinical and pathological aspects, in order to guide medical personnel in the diagnosis and opportune treatment of metastases or micro metastases. Materials and Methods: We collected data of 384 patients with clinical, radiological and histopathological diagnosis of OS, GCTb and CS that attended the National Rehabilitation Institute (INR) during 2006 to 2014. Chi-square and Fisher's exact tests were performed for data analysis. Results: In the three tumor types, the presence of metastases at diagnosis was variable (p=0.0001). Frequency of metastases was 36.7%, 31.7% and 13.2% for OS, CS and GCTb respectively. The average age had no significant difference (p>0.05) in relation to metastases, even so, patients with OS and GCTb and metastases, were older while patients with CS and metastases were younger, in comparison to patients without metastases. Males had a higher frequency of metastases (68.2%, p = 0.09) in contrast to CS and GCTb, in which the metastases was more frequent in women with 51.9% (p = 0.44) and 57.9% (p = 0.56) respectively. Broadly, metastasis was associated with primary tumors located in the femur (44.4%), followed by the tibia (15.6%); metastases was more frequent when primary tumor of GCTb and OS were in the same bones, but were located in the hip (26.3%) for CS. Conclusions: The frequency of metastases in OS, GCTb and CS is high in our population and is determined by different clinicopathological variables related to the kind of tumor. Further studies are needed in order to evaluate metastases subsequent to diagnosis and associations with survival and clinicopathological factors, as well as to determine the sensitivity and specificity of current methods of detection.

Sex-related Differences in Rat Hepatic Cytochromes P450 Expression Following Treatment with Phenobarbital or 3-Methylcholanthrene

  • Lee, Yoon-Sook;Park, Sang-Shin;Kim, Nak-Doo
    • Archives of Pharmacal Research
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    • 제15권1호
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    • pp.78-86
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    • 1992
  • The induction of hepatic cytochromes P450 and metabolic effects have been examined in male and female Sprague-Dawley rats following treatment with either phenobarbital or 3-methylcholanthrene. Hepatic cytochrome P450 levels were higher in males than in females by ~40%. Treatment of male and female rats with phenobarbital or 3-methylcholanthrene resulted in an ~1.6 and 2-fold increase, respectively, in heptic microsomal cytochrome P450 levels in both sexes, relative to untreated animals. Immunoblot analyses were performed to compare sex-related changes in P450 levels. Hepatic P45IIB1 levels in males were greater than those in females following phenobarbital treatment. 3-Methylcholanthrene-induced male hepatic microsomes exhibited greater levels of P450 females failed to exhibit a band. Mab PCN 2-13-1 against P-45-IIIA recognized an intense in uninduced microsomes from female rats. The levels of P450IIIA in males were increased 2 to 3-fold following treatment with phenobarbital, while the increase of IIIA levels in females by phenobarbital was minimal, as monitored by immunoblot analysis. Solid phase radiommunoassay using monoclonal antibodies supported the results of immunoblot analysis. Phenobarbital treatment caused a 6.5-fold increase in the monoclonal iantibody binding to IIBI in males, whereas treatment of females with phenobarbital resulted of IA levels by 3-methylcholanthrene was also greater in females than in males (10-vs. 8-fold) although the levels of induced IA were comparable inboth sexes, as assessed by radiommunoassay. Radioimmunoassay also showed that hepatic IIEI level was 1.5-fold higher in males than in females and that either phenobarbital or 3-methylcholanthrene treatment caused 80% to 40% decrease in IIEL levels, relative to control, in both sexes. Sex-related metabolic activities were examined in hepatic microsomes. Hexobarbital hydroxylase activity was 2-to 3-fold higher in uninduced microsomes from males than that from females. This hydroxylase activity was increased 2-and 3-fold in males and females, respectively, following phenobarbital treatment, as compared to controls. Addition females produced 64% and 84% inhibition of hexobarbital oxidation, respectively. Aryl hydrocarbon hydroxylase activity was increased -12 and 26-fold in males and females respectively. Following phenobarbital treatment, as compared to controls. Addition of anti-P450IIB1 antibody to phenobarbital-induced hepatic microsomes from males and females produced 64% and 84% inhibition of hexobarbital oxidation, respectively. Aryl hydrocarbon hydroxylase activity was increased -12 and 26 fold in males and females, respectively, following 3-methylcholanthrene treatment relative to controls. The anti-P-450IA antibody inhibitable rate of aryl hydrocarbon hydroxylase activity was comparable in both sexes following 3-methylcholanthrene treatment relative to controls. The anti-P450LA antibody inhibitable rate of aryl hydrocarbon hydroxylase activity was comparable in both sexes following 3-methylcholanthrene treatment (-70%). These results demonstrate that levels of hepatic P450IIB1 or P450IA are greater in male than in female for untreated, phenobarbital-or-3-methylcholanthrene treated rats. In addition, the relative for untreated phenobarbital-or 3-methylcholanthrene treated rats. In addition, the relative increase of phenobarbital-or 3-methylcholanthrene treated rats. In addition, the relative increase of phenobarbital-or 3-methylcholanthrene treated rats. In addition, the relative increase of P450IIB1 or IA phenobarbital or 3-methylcholanthrene is more significant in females.

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영남육괴 중부 무주 지역에 위치하는 선캠브리아기 화강편마암 및 앰피볼라이트 시추코아의 Sm-Nd 연대 및 지구화학적 특징 (Geochemistry and Sm-Nd isotope systematics of Precambrian granitic gneiss and amphibolite core at the Muju area, middle Yeongnam Massif)

  • 이승구;김용제;김건한
    • 암석학회지
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    • 제14권3호
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    • pp.127-140
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    • 2005
  • 영남육괴의 중부의 무주군 적상면 삼유리 일대에는 선캠브리아기 원남층군에 해당되는 화강암질 편마암, 반상변정 화강암질 편마암과 우백질 편마암이 분포한다. 이 논문에서는 화강암질 편마암 지역에서 200m심도 까지 굴착한 시추코아의 주성분, 미량성분, 희토류원소 그리고 Sm-Nd, Rb-Sr 동위원소 자료의 지구화학적 의의를 토의하고자 한다. 시추코아의 암상은 심도에 따라 변하고, 주로 화강암질 편마암과 앰피볼라이트로 구성되어 있다. 주성분 및 미량성분의 화학조성 자료를 토대로 한 연구지역내 화강암질 편마암 및 앰피볼라이트의 기원물질은 각각 TTG(Tonalite-Trondhjemite-Granodiorite) 계열 및 솔레아이트 계열의 암석에 속한다. 희토류원소의 분포도를 보면 경희토류(La-Sm)와 중희토류(Gd-Lu)의 변화 및 Eu의 부(-)의 이상이 매우 다양하다. Sm-Nd 동위원소자료에 따른 등시선에 의하면 $2,026{\pm}230(2{\sigma})$ Ma의 연대를 보여주며, 이때의 Nd 초기치는 $0.50979{\pm}0.00028(2{\sigma})$이다. 그리고 ${\epsilon}_{Nd}$(2.0 Ga)값은 -4.4로 연구지역 변성암류의 기원물질이 고기의 지각물질임을 지시해준다. 이 값은 북중국지괴 시생대 기반암의 진화영역에 속하며, 특히 Lee et al.(2005)이 제안한 영남육괴내 Nd 동위원소 초기치의 진화와 일치하는 상관성을 갖는다. 그리고 앰피볼라이트의 희토류원소 분포도와 Nd 초기치는 앰피볼라이트의 기원물질이 결핍된 맨틀과 지각을 형성하기 시작한 초기마그마와 매우 유사함을 지시해준다.

가정식사 대용식(Home meal replacement) 제품 유형별 소비자의 선호도, 만족도, 재구매 의사 분석 (Preference, Satisfaction, and Repurchase Intention of Consumers for Home Meal Replacements(HMR) by Product Categories)

  • 정라나;양일선;이혜영
    • 한국식품조리과학회지
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    • 제23권3호통권99호
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    • pp.388-400
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    • 2007
  • The purpose of this study was to identify the characteristics of consumers who purchase home meal replacements (HMR) and to analyze the differences for frequency of use, preference, satisfaction, and repurchase intention based on HMR product categories. The subjects were adults in their twenties or older, who had used HMRs and lived in Seoul and the Gyeonggi Province of Korea. Five-hundred and fifty subjects were chosen by random sampling, and questionnaires were distributed from March 12 to 30, 2005. A total of 451 questionnaires were returned (the rate of return was 82%). The primary results of the study are as follows. First, by analyzing for differences based on the demographical characteristics of the HMR consumers, men had higher 'frequencies of use' and preference, whereas women had higher satisfaction and 'intentions to purchase again.' This implies that HMRs assist women who are usually in charge of home food preparation, based on time and cooking effort; hence a higher satisfaction among the women. Second, by analyzing for differences based on the characteristics of HMR consumers who ate the products, 'frequency of use' (p<.001), preference (p<.01), satisfaction (p<.001), and 'intention to repurchase' (p<.001) for the 'ready to eat' HMR category, by the person who prepared the food, were significantly higher for those subjects in their 20s than for those in other age groups. As for persons influenced by the meal, the teen age group had significantly lower 'frequency of use'(p<.001), preference (p<.05), satisfaction (p<.01) and 'intention to repurchase' (p<.01) than other age groups. 'Frequency of use' (p<.001) and preference (p<.05) were lower if the person influenced by the meal was one's spouse or child than if the person influenced by the meal was oneself. Third, regarding the preference for eating at home or eating out, 'frequency of use' was significantly higher than the other analyzed factors for the 'ready to eat,' 'ready to heat,' and 'ready to end-cook' HMR categories. In short, the 'frequency of use' for HMRs was higher for those who preferred to eat at home versus eating out, simply as a result of being bored with eating out, which is essentially the reason for the origin of HMR.