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Effects of Samki-eum ($s\bar{a}nq\grave{i}-y\check{i}n$ ) on Freund's Complete Adjuvant-induced Arthritic Rats (Adjuvant 유발 관절염 랫트에 대한 삼기음의 효과)

  • Choi, Eun-Sill;Jang, Hong-Gyu;Kwon, O-Gon;Woo, Chang-Hoon;An, Hee-Duk
    • Journal of Korean Medicine Rehabilitation
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    • v.23 no.3
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    • pp.1-14
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    • 2013
  • Objectives The object of this study was to observe the favorable anti-arthritic effects of Samki-eum ($s\bar{a}nq\grave{i}-y\check{i}n$) on Freund's complete adjuvant (FCA)-induced arthritic Wistar rats. Methods Rheumatoid arthritis was induced by intradermal injection of FCA, and 300, 150 or 750 mg/kg of Samki-eum ($s\bar{a}nq\grave{i}-y\check{i}n$) were orally administered once a day for 14 days from 14 days after FCA treatments, and 15 mg/kg of dexamethasone was intraperitoneally administered as reference drug in this experiment. All rats were sacrificed at 14 days after continuous oral treatment of Samki-eum ($s\bar{a}nq\grave{i}-y\check{i}n$) or intraperitoneal administration of dexamethasone, and changes on the body weight, knee circumferences, gross arthritis score, inflammatory tissue prostaglandin (PG) $E_2$ levels were monitored with cartilage collagen components and glucosaminoglycans compositions - chondroitin sulphate, heparan sulphate and hyaluronic acid in the present study. Results As results of FCA treatment, classic rheumatoid arthritis featuring dramatical decreases on the body weights, cartilage collagen contents and bone glucosaminoglycans-chondroitin sulphate, heparan sulphate and hyaluronic acid contents, with increases on the knee circumferences, gross arthritis scores and inflammatory tissue $PGE_2$ levels. However, these changes from FCA-induced rheumatoid arthritis were clearly reduced by treatment of dexamethasone and both two different dosages of Samki-eum ($s\bar{a}nq\grave{i}-y\check{i}n$) 300 and 150 mg/kg in the present study. Although FCA-induced arthritis were more favorably inhibited by treatment of dexamethasone 15 mg/kg as compared with Samki-eum ($s\bar{a}nq\grave{i}-y\check{i}n$) 300 mg/kg, marked decreases of body weights were detected in dexamethasone 15 mg/kg treated rats, and Samki-eum ($s\bar{a}nq\grave{i}-y\check{i}n$) 300 mg/kg showed similar preserve effects on the cartilage glucosaminoglycan compositions in this study. Conclusions The results obtained in this study suggest that over 300 and 150 mg/kg of Samki-eum ($s\bar{a}nq\grave{i}-y\check{i}n$) showed favorable anti-arthritic effects on the FCA-induced arthritis mediated by suppression of $PGE_2$, a inflammatory mediator. However, detail mechanism studies should be conduced in future with the screening of the biological active compounds in this herb. Although overall anti-inflammatory effects Samki-eum ($s\bar{a}nq\grave{i}-y\check{i}n$) 300 mg/kg were lowered than those of dexamethasone 15 mg/kg treated rats, Samki-eum ($s\bar{a}nq\grave{i}-y\check{i}n$) 300 mg/kg treated rats showed similar preserve effects on the cartilage glucosaminoglycan compositions in this experiment.

Tissue Engineered Cartilage Formation on Various PLGA Scaffolds (PLGA 종류와 담체의 형성 방법에 따른 인간의 조직공학적 연골형성)

  • 김유미;임종옥;정호윤;박태인;백운이
    • Journal of Biomedical Engineering Research
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    • v.23 no.2
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    • pp.147-153
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    • 2002
  • The purpose of this study was to evacuate the effect of different types of Poly(lactic-co-glycolic acid) (PLGA) scaffolds on the formation of human auricular and septal cartilages. All of the scaffolds were formed in a tubular shape for potential application for artificial trachea or esophagus with either 110,000 g/mol PLGA. 220,000 g/mol PLGA. or a combination of both. In order to maintain the tubular shape in vivo, two methods were used. One method was inserting polyethylene tube at the center of scaffolds made of 110,000 g/mol PLGA. The other method involved combination of the two different molecular weight PLGA's. The inner surface of tubular shaped scaffold made with 110,000 g/mol PLGA was coated with 220,000 9/mol PLGA to give more mechanical rigidity. Elastic cartilage was taken from the ear of a patient aged under 20 nears old and hyaline cartilage was taken from the nasal septum. The chondrocytes were then isolated. After second passage, the chondrocytes were seeded on the PLGA scaffolds followed by in vitro culture for one week. The cells-PLGA scaffold complex were implanted subcutaneously on the back of nude mice for 8 weeks. The tissue engineered cartilages were separated from nude mice and examined histologically after staining with the Hematoxylin Eosin. The morphology of the scaffolds were examined by scanning electron microscopy. The pores were well formed and uniformly distributed in the various PLGA scaffolds. After 8 weeks in vivo culture, cartilage was well formed with 110,000 g/mol PLGA. however lumen had collapsed. In contrast. a minimal amount of neocartilage was formed with 220,000 g/mol PLGA, while the architecture of scaffold and lumen were well preserved. Elastic cartilage formed more neocartilage than hyaline. Hyaline and elastic neocartilage were well formed on 110,000 g/mol PLGA with the polyethylene tube, exhibiting mature chondrocytes and preservation of the tubular shape. It was found that 110,000 g/mol PLGA was more appropriate for cartilage formation but higher molecular weight polymer was necessary to maintain the three dimensional shape of the scaffold.

Job consistency and occupational satisfaction of dental hygienists by educational period of college (일부 치과위생사의 대학졸업연한 차이에 따른 희망진로와 현 근무처와의 일치도 및 직업 만족도 조사)

  • Choi, Yong-Keum;Kim, Kyeong-Mi;Kim, Sun-Il;Shin, Bo-Mi;Ryu, Da-Young;Jung, Se-Hwan;Lee, Min-Sun
    • Journal of Korean society of Dental Hygiene
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    • v.11 no.5
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    • pp.685-693
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    • 2011
  • Objectives : Five years have passed since the departments of dental hygiene with four-year term released their graduates. It is necessary to investigate concordance between desired career and current job and job satisfaction in dental hygienists according to graduation term. Accordingly, a survey on concordance between desired career and current job and job satisfaction in dental hygienists according to graduation term was conducted to obtain a basis necessary for providing right job consciousness to students of departments of dental hygiene. Methods : Of departments of dental hygiene nationwide, a total of four departments consisting of two departments with 3-year term and two departments with 4-year term were randomly selected. Of 683 graduates for 2006-10 of the selected departments, 163 graduates who agreed to participate in this study through telephone and e-mail were chosen as subjects. The data of 159 graduates were analyzed except for 4 graduates who did not respond to job satisfaction. The questionnaire consisted of a total of 17 questions: 5 general questions such as graduation term, and current job and salary, 2 questions for desired career at the time of entrance and graduation, and 10 questions for the satisfaction of current job and working environments. Concordance between the desired career at the time of entrance and graduation and current job was calculated using Kappa-value. A cross analysis was conducted to investigate job satisfaction according to general features and graduation term. A statistical significance was examined using $X^2$-test (p<0.05). Results : The Kappa-value for concordance between the desired career at the time of graduation and the current job was 0.288, showing slightly low concordance. In particular, the Kappa-value was 0.089 in the graduates of departments of dental hygiene with 3-year term, which showed significantly low concordance. The job satisfaction of the graduates was 49.1%, which was higher in the graduates with 4-year term than in the graduates with 3-year term, but was statistically insignificant (p>0.05). The detailed job satisfaction was all higher in the graduates with 4-year term than in the graduates with 3-year term except for distance to a working place, but a statistical significance was only found in working place recognition and regional status (p<0.05 ). Conclusions : This study showed differences in concordance between desired career and current job and job satisfaction between the graduates of departments of dental hygiene with 3-year term and the graduates of departments of dental hygiene with 4-year term. Therefore, the curriculum of department of dental hygiene is required to be more specifically applied in accordance with graduation term. In addition, a further study is required to develop specialized curriculums in accordance with graduation term.

An Animated Documentary Study of Korean Youth Culture and Identity (한국 청소년들의 온라인 게임문화와 정체성에 관한 애니메이션 다큐멘터리 연구)

  • Park, Man
    • Cartoon and Animation Studies
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    • s.45
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    • pp.397-415
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    • 2016
  • This paper will investigate how animated practice can be a research form as practice-led research in an ethnography approach. This practice-led research will explore the issue of the construction of contemporary identities (based on the strange case of Dr. Jekyll and Mr. Hyde) and in particular, the Korean youth culture and identity, exemplified, for example, creation of 'avatars' in the virtual characters of animated online games such as Massively Multiplayer Online Role-playing Games (MMORPGs). In this proposed discussion, I will argue that the sudden period of change in contemporary Korea bears some resemblance to the Victorian era as explored in gothic fiction (e.g. Jekyll and Hyde). In this sense, my animation investigates the connection between the fictional Jekyll and Hyde and a real murder incident by a young Korean boy, which actually happened on the 16th November 2010, in SouthKorea.I will, therefore, construct this practice-led research to obtain the primary data consisted of online and offline practices in 'social ethnography'. These practices engage with specific Korean youth identity, comparing the 'avatar' with the real lives of participants. However, this paper will only focus on the (ethnographic) research process and strategy, using animated (visual) practices, rather than giving the meaning of the specific case of 'Korean-ness'. Eventually, I will explore the four different animated representations as it presents the distinctive animated realties or documentaries by online and offline practices. My intention is to visually interpret the issue of 'Korean-ness' within its socio-cultural context, adapting the convention and code of Jekyll and Hyde concept into an animated documentary in the 'virtual' world (auto-animated documentary by recording avatar interviews and online game footages) and the 'real' world (self-created animated documentary, based on real people and events).

Pressor Action of Intracerebroventricular Nicotine and Muscarine in the Rabbit (가토 측뇌실내 Nicotine 및 Muscarine의 혈압상승작용에 관하여)

  • Lee, Choong-Kyoung
    • The Korean Journal of Pharmacology
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    • v.27 no.1
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    • pp.21-31
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    • 1991
  • When administered intracerebroventricularly (icv), cholinergic nicotinic agents, nicotine and DMPP, as well as cholinergic muscarinic agents, muscarine and bethanechol, produced pressor responses in urethane-anesthetized vagotomized rabbits. The response patterns to nicotine and to DMPP were similar, while the bethanechol response resembled the muscarine pattern. The pressor response to nicotine and DMPP was markedly inhibited by icv mecamylamine but not by icv pirenzepine, whereas the response to muscarine and bethanechol was inhibited by icv pirenzepine but not by icv mecamylamine, suggesting that both nicotinic and muscarinic receptors in the brain are involved in the action. Intravenous pretreatments of animals with regitine, reserpine, enalapril, saralasin, both regitine and enalapril, both regitine and saralasin, SK&F-100273 did not prevent the pressor response to nicotine and muscarine. Iv pretreatments with both regitine and SK&F-100273 inhibited the nicotine response without affecting the muscarine response, whereas pretreatments with three agents, regitine, enalapril and SK&F-100273, inhibited the muscarine response. The nicotine-induced elevated blood pressure as well as the muscarine-induced were lowered by regitine but not by enalapril or by SK&F-100273. Enalapril was without effect on the nicotine hypertension in rabbits treated with regitine or both regitine and SK&F-100273, whereas SK&F-100273 lowered the nicotine hypertension in regitine-treated animals. Enalapril did not enhance the lowering effect of SK&F-100273 in regitine-treated ones, nor did it cause a fall of the muscarine hypertension induced in regitine-treated rabbits, but it did lower the blood pressure in animals treated with both regitine and SK&F-100273. Likewise, SK&F-100273 did not cause a fall of the muscarine hypertension induced in regitine-treated rabbits, but it did lower the blood pressure in animals treated with both regitine and enalapril. These data suggest that the nicotine-induced hypertensive state is related to at least two systems in the periphery-sympathetic and vasopressin, whereas in the muscarine-induced hypertensive state three systems in the periphery are involved, i.e., the sympathetic, vasopressin and angiotensin system. The hypotensive effect of regitine on basal arterial blood pressure levels of rabbits was not influenced by pretreatment with either of enalapril or SK&F-100273, but significantly potentiated by treating with both enalapril and SK&F-100273, suggesting participation of the sympathetic and the renin-angiotensin system as well as the vasopressin system in maintenance of arterial blood pressure.

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Hydrochemistry and Occurrence of Natural Radioactive Materials within Borehole Groundwater in the Cheongwon Area (청원지역 시추공 지하수의 수리화학 및 자연방사성물질 산출 특성)

  • Jeong, Chan-Ho;Kim, Moon-Su;Lee, Young-Joon;Han, Jin-Seok;Jang, Hyo-Geun;Jo, Byung-Uk
    • The Journal of Engineering Geology
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    • v.21 no.2
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    • pp.163-178
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    • 2011
  • A test borehole was drilled in the Cheongwon area to investigate the relationship between geochemical environment and the natural occurrence of radioactive materials (uranium and Rn-222) in borehole groundwater. The borehole encountered mainly biotite schist and biotite granite, with minor porphyritic granite and basic dykes. Six groundwater samples were collected at different depths in the borehole using the double-packed system. The groundwater pH ranges from 5.66 to 8.34, and the chemical type of the groundwater is Ca-$HCO_3$. The contents of uranium and Rn-222 in the groundwater are 0.03-683 ppb and 1,290-7,600 pCi/L, respectively. The contents of uranium and thorium in the rocks within the borehole are 0.51-23.4 ppm and 0.89-62.6 ppm, respectively. Microscope observations of the rock core and analyses by electron probe microanalyzer (EPMA) show that most of the radioactive elements occur in the biotite schist, within accessory minerals such as monazite and limenite in biotite, and in feldspar and quartz. The high uranium content of groundwater at depths of -50 to -70 m is due to groundwater chemistry (weakly alkaline pH, an oxidizing environment, and high concentrations of bicarbonate). The origin of Rn-222 could be determined by analyzing noble gas isotopes (e.g., $^3He/^4He$ and $^4He/^{20}Ne$).

A New Forma of Acanthopanax Species(I) (신품종(新品種)을 포함한 한국산(韓國産) Acanthopanax속(屬)의 분류(分類)(I))

  • Yook, Chang-Soo;Lee, Dong-Ho;Seo, Yoon-Kyo
    • Korean Journal of Pharmacognosy
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    • v.7 no.3
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    • pp.179-190
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    • 1976
  • 1. The Korean Acanthopanax genus includes 12 kinds consisting of 9 species and 3 forma. 2. The Korean Oga-pi which is on market sale has been used as bark for the medicinal purpose, and Oga-pi shall use Radicis Cortex. That is why it is basic rule that herbalogy shall use Radicis Cortex. 3. The origin of Oga-pi on sale is Acanthopanax sessiliflorum forma chungbunensis C.S. Yook. 4. $C_{HUNG}\;and\;N_AKAI'S}$ report on A. koreanum told us that there are brown hair on the mid-leaf junction, but in addition to it, our investigation was resulted in the fact that there are thorn along mid-rib sometimes. 5. 2 kinds of new forma are similar to A. sessiliflorum, but are different in the view-point of chemotaxonomy, compared with A. sessiliflorum. In its morphology, we can find some difference between 2 kinds of new forma and A. sessiliflorum. Our effort of examination on documents tell us that the all plants growing in the central part of our country is A. sessiliflorum forma chungbunensis C.S. Yook. The one which has thorn on both side among the plants collected in Mt. Dukyu, is called A. sessiliflorum forma nambunensis C.S. Yook. 6. A. sessiliflorum is growing in the southern part in Korea, and most Chungbu Oga-pi A. sessiliflorum forma chungbunensis in the central part of our country. For the convenience of our study, the key of Korean Acanthopanax plant is classified into, I-IV, as shown on the following items: I. No hair on both side of leaf A. Flower stalk is longer than petiole, and there are thorn under the petiole (5-7 stigma).${\cdots}A.\;sieboldianum$. B. Flower stalk is longer than petiole, or same length. The serration lie down, and the stem has short thorn (stigma is divided into 3 part).${\cdots\;\cdots}A.\;seoulense$ II. There are a lot of thorn or hair on back of leaf. A. A lot of thorn and hair on the vein of leaf back, and a number of small thorn on petiole.${\cdots}A.\;chiisanensis$. B. There are thorn on the vein of leaf back.${\cdots\;\cdots}A.\;sessiliflorum\;forma\;chungbunensis.$ III. There are hairs on both side of leaf. A. There are small hairs on the back of leaf.${\cdots\;\cdots}A.\;sessiliflorum.$ B. There are small hairs on both side of leaf.${\cdots\;\cdots}A.\;sessiliflorum\;f.\;nambunensis.$ C. There are thick hairs on junction of main vein on back of leaf.${\cdots\;\cdots}A.\;koreanum.$ D. There are brown hairs on vein of leaf back, and brown hairs on small petiole.${\cdots\;\cdots}A.\;rufinerve.$ E. There are shrunk hairs in grey-brown on back of leaf, and tense hairs on new branch (one stigma).${\cdots\;\cdots}A.\;divaricatum.$ IV. There are long thorn, just like needles, on the stem and petiole. A. Long needle grows on whole stem tensely, and long needles on petiole.${\cdots\;\cdots}A.\;senticosus.$ B. There are no needles, just like needles aid hairs on petiole, and needles grow on the stem thinly.${\cdots\;\cdots}A.\;asperatus.$ C. There are no needle on small brarch, leaf and inflorescence are larger than A. senticosus. ${\cdots\;\cdots}A.\;senticosus\;forma\;inermis.$.

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An Empirical Study on the Importance of Psychological Contract Commitment in Information Systems Outsourcing (정보시스템 아웃소싱에서 심리적 계약 커미트먼트의 중요성에 대한 연구)

  • Kim, Hyung-Jin;Lee, Sang-Hoon;Lee, Ho-Geun
    • Asia pacific journal of information systems
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    • v.17 no.2
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    • pp.49-81
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    • 2007
  • Research in the IS (Information Systems) outsourcing has focused on the importance of legal contracts and partnerships between vendors and clients. Without detailed legal contracts, there is no guarantee that an outsourcing vendor would not indulge in self-serving behavior. In addition, partnerships can supplement legal contracts in managing the relationship between clients and vendors legal contracts by itself cannot deal with all the complexity and ambiguity involved with IS outsourcing relationships. In this paper, we introduce a psychological contract (between client and vendor) as an important variable for IS outsourcing success. A psychological contract refers to individual's mental beliefs about his or her mutual obligations in a contractual relationship (Rousseau, 1995). A psychological contract emerges when one party believes that a promise of future returns has been made, a contribution has been given, and thus, an obligation has been created to provide future benefits (Rousseau, 1989). An employmentpsychological contract, which is a widespread concept in psychology, refers to employer and employee expectations of the employment relationship, i.e. mutual obligations, values, expectations and aspirations that operate over and above the formal contract of employment (Smithson and Lewis, 2003). Similar to the psychological contract between an employer and employee, IS outsourcing involves a contract and a set of mutual obligations between client and vendor (Ho et al., 2003). Given the lack of prior research on psychological contracts in the IS outsourcing context, we extend such studies and give insights through investigating the role of psychological contracts between client and vendor. Psychological contract theory offers highly relevant and sound theoretical lens for studying IS outsourcing management because of its six distinctive principles: (1) it focuses on mutual (rather than one-sided) obligations between contractual parties, (2) it's more comprehensive than the concept of legal contract, (3) it's an individual-level construct, (4) it changes over time, (5) it affects organizational behaviors, and (6) it's susceptible to organizational factors (Koh et al., 2004; Rousseau, 1996; Coyle-Shapiro, 2000). The aim of this paper is to put the concept, psychological contract commitment (PCC), under the spotlight, by finding out its mediating effects between legal contracts/partnerships and IS outsourcing success. Our interest is in the psychological contract commitment (PCC) or commitment to psychological contracts, which is the extent to which a partner consistently and deeply concerns with what the counter-party believes as obligations during the IS project. The basic premise for the hypothesized relationship between PCC and success is that for outsourcing success, client and vendor should continually commit to mutual obligations in which both parties believe, rather than to only explicit obligations. The psychological contract commitment playsa pivotal role in evaluating a counter-party because it reflects what one party really expects from the other. If one party consistently shows high commitment to psychological contracts, the other party would evaluate it positively. This will increase positive reciprocation efforts of the other party, thus leading to successful outsourcing outcomes (McNeeley and Meglino, 1994). We have used matched sample data for this research. We have collected three responses from each set of a client and a vendor firm: a project manager of the client firm, a project member from the vendor firm with whom the project manager cooperated, and an end-user of the client company who actually used the outsourced information systems. Special caution was given to the data collection process to avoid any bias in responses. We first sent three types of questionnaires (A, Band C) to each project manager of the client firm, asking him/her to answer the first type of questionnaires (A).

Identifying Antecedents of Service Innovation: Based on Service-Dominant Logic and Resource-Advantage Theory (서비스 혁신의 선행요인에 관한 연구: 서비스 지배적 논리와 자원 우위 이론을 중심으로)

  • Ryu, Hyun-Sun;Han, Jin Young
    • Information Systems Review
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    • v.18 no.2
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    • pp.79-106
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    • 2016
  • Service innovation is one means of gaining an advantage in a highly competitive environment. Although numerous studies have stressed the importance of service innovation, traditional good-dominant logic is still used in service innovation literature. Furthermore, few studies have been conducted on the link between service innovation and its antecedents in terms of service-oriented approach. To fill the gap, this article theoretically and empirically examines service innovation and its antecedents and consequences. Based on service-dominant logic and resource advantage theory, the current study aims to understand the effect of antecedents on service innovation as well as to identify the effect of service innovation on firm performance (i.e., non-financial and financial performance). Three service innovation activities, namely service creation-focused innovation, service delivery-focused innovation, and customer interaction-focused innovation, and four antecedents of service innovation, including human resource management capability, collaboration capability, marketing capability, and information technology capability, are identified based on Den Hertog (2000)'s service innovation framework. By using the empirical data collected from 189 service firms in Korea, this study explores the causal relationship among antecedents, service innovation and firm performance. Findings indicate that human resource management and marketing capabilities influence the three types of service innovation, whereas collaboration and information technology capabilities have a significant effect on both service creation-focused innovation and service delivery-focused innovation. In particular, human resource management capability is strongly related to customer interaction-focused innovation. The three types of service innovation have a positive influence on non-financial performance, whereas service delivery-focused innovation and customer interaction-focused innovation positively influence financial performance. These results support the crucial effects of antecedents, such as human resource management, collaboration, marketing and information technology capabilities, on service innovation.

An Examination of Knowledge Sourcing Strategies Effects on Corporate Performance in Small Enterprises (소규모 기업에 있어서 지식소싱 전략이 기업성과에 미치는 영향 고찰)

  • Choi, Byoung-Gu
    • Asia pacific journal of information systems
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    • v.18 no.4
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    • pp.57-81
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    • 2008
  • Knowledge is an essential strategic weapon for sustaining competitive advantage and is the key determinant for organizational growth. When knowledge is shared and disseminated throughout the organization, it increases an organization's value by providing the ability to respond to new and unusual situations. The growing importance of knowledge as a critical resource has forced executives to pay attention to their organizational knowledge. Organizations are increasingly undertaking knowledge management initiatives and making significant investments. Knowledge sourcing is considered as the first important step in effective knowledge management. Most firms continue to make an effort to realize the benefits of knowledge management by using various knowledge sources effectively. Appropriate knowledge sourcing strategies enable organizations to create, acquire, and access knowledge in a timely manner by reducing search and transfer costs, which result in better firm performance. In response, the knowledge management literature has devoted substantial attention to the analysis of knowledge sourcing strategies. Many studies have categorized knowledge sourcing strategies into intemal- and external-oriented. Internal-oriented sourcing strategy attempts to increase firm performance by integrating knowledge within the boundary of the firm. On the contrary, external-oriented strategy attempts to bring knowledge in from outside sources via either acquisition or imitation, and then to transfer that knowledge across to the organization. However, the extant literature on knowledge sourcing strategies focuses primarily on large organizations. Although many studies have clearly highlighted major differences between large and small firms and the need to adopt different strategies for different firm sizes, scant attention has been given to analyzing how knowledge sourcing strategies affect firm performance in small firms and what are the differences between small and large firms in the patterns of knowledge sourcing strategies adoption. This study attempts to advance the current literature by examining the impact of knowledge sourcing strategies on small firm performance from a holistic perspective. By drawing on knowledge based theory from organization science and complementarity theory from the economics literature, this paper is motivated by the following questions: (1) what are the adoption patterns of different knowledge sourcing strategies in small firms (i,e., what sourcing strategies should be adopted and which sourcing strategies work well together in small firms)?; and (2) what are the performance implications of these adoption patterns? In order to answer the questions, this study developed three hypotheses. First hypothesis based on knowledge based theory is that internal-oriented knowledge sourcing is positively associated with small firm performance. Second hypothesis developed on the basis of knowledge based theory is that external-oriented knowledge sourcing is positively associated with small firm performance. The third one based on complementarity theory is that pursuing both internal- and external-oriented knowledge sourcing simultaneously is negatively or less positively associated with small firm performance. As a sampling frame, 700 firms were identified from the Annual Corporation Report in Korea. Survey questionnaires were mailed to owners or executives who were most erudite about the firm s knowledge sourcing strategies and performance. A total of 188 companies replied, yielding a response rate of 26.8%. Due to incomplete data, 12 responses were eliminated, leaving 176 responses for the final analysis. Since all independent variables were measured using continuous variables, supermodularity function was used to test the hypotheses based on the cross partial derivative of payoff function. The results indicated no significant impact of internal-oriented sourcing strategies while positive impact of external-oriented sourcing strategy on small firm performance. This intriguing result could be explained on the basis of various resource and capital constraints of small firms. Small firms typically have restricted financial and human resources. They do not have enough assets to always develop knowledge internally. Another possible explanation is competency traps or core rigidities. Building up a knowledge base based on internal knowledge creates core competences, but at the same time, excessive internal focused knowledge exploration leads to behaviors blind to other knowledge. Interestingly, this study found that Internal- and external-oriented knowledge sourcing strategies had a substitutive relationship, which was inconsistent with previous studies that suggested complementary relationship between them. This result might be explained using organizational identification theory. Internal organizational members may perceive external knowledge as a threat, and tend to ignore knowledge from external sources because they prefer to maintain their own knowledge, legitimacy, and homogeneous attitudes. Therefore, integrating knowledge from internal and external sources might not be effective, resulting in failure of improvements of firm performance. Another possible explanation is small firms resource and capital constraints and lack of management expertise and absorptive capacity. Although the integration of different knowledge sources is critical, high levels of knowledge sourcing in many areas are quite expensive and so are often unrealistic for small enterprises. This study provides several implications for research as well as practice. First this study extends the existing knowledge by examining the substitutability (and complementarity) of knowledge sourcing strategies. Most prior studies have tended to investigate the independent effects of these strategies on performance without considering their combined impacts. Furthermore, this study tests complementarity based on the productivity approach that has been considered as a definitive test method for complementarity. Second, this study sheds new light on knowledge management research by identifying the relationship between knowledge sourcing strategies and small firm performance. Most current literature has insisted complementary relationship between knowledge sourcing strategies on the basis of data from large firms. Contrary to the conventional wisdom, this study identifies substitutive relationship between knowledge sourcing strategies using data from small firms. Third, implications for practice highlight that managers of small firms should focus on knowledge sourcing from external-oriented strategies. Moreover, adoption of both sourcing strategies simultaneousiy impedes small firm performance.